psych 3313 quiz 3

what is allowed in the blood brain barrier via active transport

(protein channel/pump using ATP) - glucose - amino acids which are important for the survival of brain

On Old Olympus Towering Tops A Finn And German Viewed Some Hops

(sensory, motor, both) some say marry money but my big sister believes brains matter more

what are epigenetic markers

Epigenetic marks tell your genes to switch on or off

Genes that are methylated are...

Essentially turned off. This process performs essential roles in cell differentiation and embryonic development

Fetus at 11 weeks, via radial glial cells, inside out development process radial glial cells

Even more specialization is seen - in the cross section we see the cells starting to divide in the ventricular zone (this is normal) however we see a specialized glial cell called the radial glia which are the structural scaffold that can be pictured as a rope that you have to climb in gym class - we see that the new neurons wrap themselves around the radial glia and climb their way out and expand the brain tissue out towards the surface of the brain - this is called INSIDE OUT DEVELOPMENT because we are starting at the center and moving outwards

What is part of the midbrain?

mesencephalon which is part of the brainstem (midbrain)

Efferent

motor nerve fibers, that conduct the impulses from the CNS to effectors Exit, descending

unplanned genetic diversity causes (3)

mutations: erros in DNA replication single nucleotide polymorphisms (SNPs): DNA sequence change at one nucleotide so for example changing an adenosine to a cytosine or a guanine (a single switch) copy number variations (CNVs): having too many or too few copies (variable numbers of genes/gene series - associated with Huntington's disease or Down syndrome or fragile x disease

contralateral

oppositve sides of the midline ex. right arm and left leg (think X)

Ectoderm

outermost germ layer of the gastrula; becomes skin, hair, and neural tissue (nervous system), ecto = "outer" - this is because it folds in and that is how the nervous system gets involved/where the nervous system starts in this layer

ACHOO Syndrome

sun sneezing (in dark room and go out in bright sunlight), a genetic condition and is dominant (affects 18-30% of population), - overstimulation of trigeminal nerve by the light and instead of blinking the body panicks and says if you are sneezing, you are going to blink (for a longer closing of eyes) - 5th cranial nerve pair

superior or dorsal

superior: toward the back dorsal: higher in brain vertical

gene x environment interactions

susceptibility to a trait depends on a particular combination of a gene and environment

codominate

the condition in which both alleles in a heterozygous organism are expressed

what is the purpose of DNA?

to give us the genes which is the "blueprint" for making different protein products that the cell can use to stay alive/perform diff functions ex. a lot of receptors are a combo of diff proteins

proximal

close to center - CNS ex. injured you arm where if you hurt your elbow that would be proximal ex. shoulders are proximal relative to elbows

exons

coding sequence - not all of our DNA

how did we figure out heritability?

combination of twin and adoption and family studies - the Minnesota study of twins reared apart is one of the ways we really accounted for that contribution of nature/nurture

do girls or boys hit puberty first?

girls start earlier and typically end earlier - there is a big range though, and lots of overlap of characteristics

Dr. Kilmar studies synaptogenesis in the developing cortex by using a technique to monitor ____ utilization.

glucose

Retroviral gene therapy

"hacking a virus" - most viruses enter an organism and makes copies of themselves BUT a retrovirus gets into the host and inserts it DNA into the host's DNA so when the host goes through its normal replication process it is now making copies of the virus gene - so if we can put the genes from making a specific protein into that virus we can use a retrovirus to do large-scale editing and make that new gene become expressed retrovirus ex: HIV

epigenetics

"the code above the code" - the study of environmental influences on gene expression/phenotype that occurs without a DNA change sequence = AGCT.. this stays the same/is the blueprint, but we change how accessible it is or how active a certain section of the gene is. recall that there are some sections that are coded and some that are regulatory, this would be shifting that balance - gene activity/expression are heritable changes so these epigenetic markers can be passed on to offspring

What is part of the hindbrain

1. Metencephalon which is the pons (part of the brainstem), and cerebellum 2. Myelencephalon which is the medulla oblongata (part of the brainstem)

Disorders of brain development: categories

1. Neural tube defects 2. Genetic disorders 3. Environmental toxins

what are the 12 pairs of cranial nerves

1. Olfactory (sensory) 2. Optic (sensory) 3. Oculomotor (motor) 4. Trochlear (motor) 5. Trigeminal (both) 6. Abducens (motor) 7. Facial (both) 8. Vestibulocochlear/auditory (sensory) 9. Glossopharyngeal (both) 10. Vagus (both) 11. Spinal Accessory (motor) 12. Hypoglossal (motor)

Fast steps of female differentiation of gonads (process of female gonads)

1. Starts at the undifferentiated gonads. 2. Nothing happens Then we see that the Mullerian system matures/grows and the Wollfian system fades away By 12 weeks we see that the internal ovaries/external genitalia are starting to show differentiation in the female typical pattern - uses no specific hormones

Fast steps of male differentiation of gonads (process of male gonads)

1. Starts at undifferentiated gonads and requires the SRY gene 2. This creates the testes determining factor protein 3. This protein activates the testes 4. The testes release the 2 hormones: testosterone and anti-mullerian which further matures the Wollfian system

What is part of the forebrain?

1. Telencephalon which is the cerebrum (includes cerebral cortex, white matter, basal nuclei) (a lot of the forebrain is in this category and is the lost to develop and mature in prenatal development) 2. Diencephalon which is the thalamus, hypothalamus, and epithalamus

Functions of the internal sex organs/gonads

1. To produce the eggs (female ovaries) or the sperm (male testes) which are called gametes for sexual reproduction 2. To secrete hormones throughout much of the lifespan

Description of the movements of neurites (neurite movement)

1. We see the developing axon (the neurite) attach to the surface of the neuron cell so that it hops over it and goes towards the attractants 2. When it is by the attractants, which release chemicals to tell them they are the attractant, by the target cell, it threads a needle around it to find the right connections, which then forms the new synapse on the target cells (The repellant cells release chemicals that repulse the growth cone filopedia, so that it knows to stay away from it)

process of synaptogenesis Another explanation of the formation of the connectoins

1. We see the developing axon pathfinding 2. Early in development, we really take a more is better approach and try and connect to all possible options. We begin to see the synapse differentiation. 3. As we go through time, we see activity dependence which means that the more a particular synapse is used the more it is likely to survive or be maintained. We do not need to connect all the things, we just need to have the best/most efficient connections. So we see overtime which synapses has the best opportunity to deliver messages and see the mature synapses, and remove those that are not important 4. The interaction with the target cells can be influenced by the type of neurotransmitter by the presynaptic cell and this movement of receptors to the synaptic site (especially postsynaptic) is guided by chemical changes both pre and post synaptically - so its this interaction process of being used is important for development

examples of males being more prone to sex linked characteristics than females?

1. hemophilia: "queen Victoria's disease" because in the British royal family it has been rampant in her descendants - it is a blood clotting disorder, so if they have a flesh wound they won't clot and they are a lot more at risk for bleeding out 2. color blindness (affects 10% of males in some way and less than 0.5% of females)

what are the 3 processes that produce lasting but reversible changes in gene expression (epigenetics)?

1. histone modification 2. DNA methylation 3. Gene silencing by noncoding RNA

OPTOGENETICS what happens if blue light hits the right part of the motor cortex? hypothalamus associated with drinking?

1. the animal starts running in a circle 2. a non thirst will go over to its water dish and starts drinking right away

Why is it the ectoderm that is the nervous system? process neural tube

18 days after fertilization: ectoderm has a region in the middle that thickens and forms the neural plate 20 days after: the thickened neural plate folds in on its self which is called invagination and creates a neural groove 21 days after: process is nearly complete as it is completely closed at the top most portion (the blue region is part of the ectoderm that becomes the nervous system) 23 days after: the neural tube is really starting to close off (Occurs all in 5 days) The top part = brain Bottom part = spinal cord Line in center = part of the central canal and the ventricle

discovery of the blood brain barrier

1880s by Paul Ehrlich (studied syphilis) - had dye called triptan blue and inject in mice, when inserted into periphery all the mouses tissues were blue except the brain/spinal cord, he does it again this occurs for CNS but not PNS - hypothesized a barrier between the blood and the brain that prevents a complete flow of molecules

The nervous system will begin to form when the human embryo is about ____ old.

2 weeks

female preference for masculine faces during ovulation study (2001)

2001 study by Johnston - started with computer composite of average male face and used photoshop to slightly tweak it - female participants turned a knob and stopped it at where they thought the perfect face was RESULTS: - when conception risk was high (during ovulation) the more masculine face was picked which is casual sex encounter

accuracy in judging male sexual orientation as a fuction of fertility status

2011 data - we are looking at time from ovulation (0 = ovulation occurs) dependent measure is accuracy (woman's ability to detect and correctly identify a man's sexual orientation - the data is noisy (everywhere), but it is most accurate around the time of ovulation (60% which is not far above chance but is better than when not ovulating) - also, they did not find any effect of the woman's fertility status on their ability to judge other women's sexual orientation (they could only do men) - suggesting there may be hormonal influences or subtle cues (whether it be visual, olfactory, etc) that can determine whether it is a viable mating partner for some of the mating women

average length of menstrual cycle

28 days

the meninges

3 layers of meninges provide protection 1. Dura Mater: outermost layer, feels like thin leather, very durable, wraps brain and spinal cord 2. Arachnoid mater (ONLY in CNS) takes up lots of space, lots of blood vessels flowing through it, and thin filament strands "spider like", cerebrospinal FLUID is in the subarachnoid as well 3. Pia Mater (deepest layer closest to the brain), it is so thin it is hard to point out with naked eye, last layer of protection, transparent - provides buffer between soft CNS tissue and the hard bones

spinal nerves

31 left/right pairs - starts mixed and then splits into the afferent dorsal sensory or the efferent ventral motor pathway - laterally from spinal cord it is a mixed nerve (both sensory/motor) & as it gets closer to ventral spinal cord it splits into 2 diff directions - the motor outputs start in the ventral horn and come out - the sensory input comes in by way of the mixed nerve and there is swelling by spinal cord called a dorsal root ganglion (processing hub) and then comes into the dorsal horn

When does the weight of the brain start to decrease (measurably)?

45 yrs

How many chromosomes do humans have?

46, we are diploid so we have 2 pairs of alleles for each gene

When does the peak number of synapses occur in the visual cortex

8 months

What is happening one month after fertilization of embryo?

(This is around the time we left off with the neural tube forming and closing) - we see some differentiation that is part of the larger brain structures of the hindbrain, midbrain, and forebrain. (The broadest way to think of the regions)

cranial nerves

- 12 pairs called cranial because they enter/exit directly from brain - can be purely sensory, motor, or mixed/both

concordance rates of homosexuality in males

- 20-25% in fraternal twins - 50% in identical twins because we see that jump from fraternal to identical it supports a genetic involvement, however this is still a coin flip to whether the other twin will identifiy as homosexual a well

Jacob Syndrome "Supermale), (47, XYY) polysomies

- A lot more rare than Kleinfelter's (1 in 1000 births) - genetically and phenotypically male - normal sexual development (normal testosterone levels) - may have very slightly reduced fertility (issues) - may have increased risk for acne, learning disabilities - minor risk factor for impulsive, antisocial, and criminal misbehavior** - most people with this condition is probably not away they have it, there is not substantial fetility, growth maturation, or behavior difference

What naturally opens or weakens the BBB?

- Having high blood pressure which is one reason it is a risk factor for many other brain based problems - microwaves, ultrasonic waves, radiation. trying to deliver chemotherapy for brain cancer (usually type of things that is kept out from the BBB). they used an ultrasonic screwdriver to target high frequency ultrasonic waves and created bubbles in wrapping around of blood vessels and they took advantage of bubbles to put in the drugs - infections also weaken the BBB - people with alzheimer's disease seem to have pretty weak BBB, is it contributing or a consequence of disease? both? feedback loop? - the BBB gets weaker after any sort of damage to the CNS which is why things like chronic traumatic encephalopathy can occur after multiple concussion/brain injuries

an example of a CNV: Huntington's Disease

- Huntington's disease is dominant, so if someone has the disease there is a 50% chance that they will pass it on to their offspring - something cruel: its onset is usually mid to middle adulthood (30-40 years) after many have had kids already - it is a copy number problem b/c there is a protein called Huntington that is associated with repetitions of a certain genome sequence of CAG (these are the nucleotides in the codon that get repeated) - if there is less than 35 copies then the person is going to have the normal form of the protein (no disorder) - if someone has more than 35 repeats, then the protein (Huntington) is going to mutate and affect the motor neurons which eventually results in Huntington's chorea (writhing painful dance where it's unwanted movement that occurs involuntarily, it has cognitive decline, and is a fatal condition) - the more repeats of CAG there are, it is associated with an earlier onset or a more severe/faster progression of the disease

Candidate gene approach (middle)

- Hypothesis driven "if this, then that" - Confirmatory (you expect there to be a relationship and you're looing for supporting evidence) - This is more systematic (scanning) approach rather than looking at as much data as you can - looks at specific examples, we know something about the underlying biology of certain disorders, so we can pick what genes are likely to be important in these outcomes, and we will study how the risk associated with that gene unfolds across development/interacts - already found genes

human menstrual cycle and mood conditions

- Premenstrual syndrome (PMS): Physical and psychological sympotoms immediately prior to onset of menstruation due to the changing hormonal environment - Premenstrual Dysphoric Disorder (PMDD): Premenstrual mood changes are unusually severe, affecting cognition and daily life (more severe than PMS and meet characteristics of psych disorder) - Postpartum depression (& anxiety & psychosis, less common): new mothers experience feelings of depression due to rapidly changing hormonal environment, occurs in 10% of new mothers, due to rapidly changing hormonal environment

Stages of neural development

- a lot of these are co-occuring (a lot of overlap, not you finish one step and then you start one step right after) and some are long processes 1. Neurogenesis/gliogenesis (making cells) 2. Migration via radial glial cells (all starting at one point and have to expand outward) 3. Differentiation (specialization, how they take on their specific structures/functions) 4. Circuit Formation/synaptogenesis (neurons communication with other neurons and how things get wired up/connected into circuits) once axons reach destination, they must establish new synapses 5. Neuron Death (Apoptosis) (normal and healthy and important most of the time) 6. Pruning and Rearrangment of connections (dynamic process and development can continue through many diff stages)

Experiment including activational/organizational through the lens of critical periods

- adults rodents show very sex typical reproductive behaviors -the female typically develops a receptive posture, arching their back (called lordosis) - the male typically mounting posture where they can engage in "intromission" (the male is humping the female) - if we have a male pup whose testes are cut off on day 1 (reduces ability to make testosterone) we change the organizational effect, then we give it estrogen later on, we find that the male rat exhibits that female mating posture (lordosis) - similarly, we can give a female rat testosterone on day 1 to masculinize the organizational effect. then, if we add more testosterone later on, the female will exhibit the intromission mounting male position

facts about the human genome

- approx. 23,00 genes in the human genome - the haploid human genome possesses about 3 billion nucleotides - this means we have 22 pairs of autosomes (most of the chromosomes) plus the 1 pair which is the sex chromosomes

monitoring centers

- area postrema, the brain's "vomiting center", so when toxic substance that enters bloodstream and crosses the area postrema. if too much activity the person vomits, protecting ourselves by purging the toxin, binge drinking vomitting occurs b/c of the area postrema - hypothalamus has areas that sample blood directly to measure fluid content/temp to be weak for BBB

What causes meningitis?

- bacterial (worst kind) - could be fungal reasons (pharma company made sterioids for medical and there was contamination that had outbreak of this) - viral which is most common and affects younger individuals, best hope of recovery (even neonates), self resolving

describe the blocking/unblocking of epigenetics

- blocking a gene to stop transcription and the expression - unlocking a gene to allow transcription and expression going back and forth between blocking and unblocking is a very dynamic process that allows certain parts to be more accessible than others which is based on part on some interaction in environment/experiences over time

Brain in adulthood

- brain is fully mature by at least age 25; weight of the brain measurably starts to decrease at age 45 Neurogenesis (new cells in adulthood?) - possible roles in adult learning and forming new memories - decline of neurogenesis is associated with cognitive decline (when we stop making new cells, we notice cognitive decline) (which is found in animal models) - multiple reserves help resist loss of function (lots of work in animals that suggests that neurogenesis may be one of the ways for things like antidepressants to gain their effectiveness) Brain changes in healthy aging - we see neural decline (outside of disorder like parkinson's/alzheimer's) in the medial temporal lobe which is the area associated with memory - we see neural decline in executive pathways connecting the basal ganglia and frontal lobes which is associated with the stereotypical behaviors of advanced age

optogenetics

- came on the scene around 2010, it has exploded since then - we got light sensitive channels (from algae) and insert them into the genome so that they could be expressed. - if we expose the light-sensitive channels to the right wavelength of light they will open and will be activate (turns the cell on) - and if we expose them to a different wavelength of light it will close the channel - light activates light responsive protein called opsin to turn a neuron on or off An ability to insert a gene into a cell and basically turn it off or on with light

Which approaches have to do with the genetic information as it is?

- candidate gene approach - genome wide association study - the black/white circles/squares

what are the differences between the sexes?

- continued expression of genes on both X and Y chromosomes, especially in the brain - organizational and activational hormone effects (testosterone and estrogens) - epigenetics (diff experiences changing gene expression) - societal and cultural influences (feedback loops)

hormones and sexual orientation

- early exposure to sex hormones influences adult sexual behavior in animals and humans (rat sex demonstration) (correlaive evidence in humans but this does not lead to causation) - possible biomarkers: how the otoacoustic emissions of lesbian and bisexual women showed a slightly more masculinized pattern - 2D:4D ratio between index and ring finger and how that can be different - correlative studies show that being the youngest male in a family of lots of males increases the likelihood of identifying as homosexual (this could be b/c the amount of prenatal androgens can almost build up over time in the maternal environment so the mother's immune response to the Y chromosome, which she does not normally have, may change with subsequent male pregnancies ovver time)

Environmental toxins that contribute to disorders of brain development

- fetal alcohol syndrome - prenatal exposure to other drugs

sexual orientation and verbal fluency tasks

- gay (homosexual) males outperformed straight (heterosexual) females - gay (homosexual) males and straight (heterosexual) females outperformed straight (heterosexual) males and lesbian (homosexual) females - very complicated, why asking, what does it mean

genetics and sexual orientation

- genetics appears to influence sexual orientation, although the exact mechanisms/specific genes/specific heritability ratios are not well understood - may have a direct effect on sexual orientation or indirect effects through diff things like the amount of prenatal androgen environments, etc - best correlations have been found on chromosome 8 and chromosome X which seemed to correlated with a predictive sexual orientation (slippery slope, compare to the supermale gene correlated with certain types of behavior)

sympathetic nervous system (output)

- has 2 different neurons involved here (whereas SNS only has one) that release the ACh as well as norepinephrine at the effector which increases heart rate/blood pressure/blood flow to skeletal muscles (tense) - pupils dilate (get bigger, more access to visual info) - inhibits digestive functions - mobilizes body systems during activity ("fight of flight") - signals can be stimulatory or inhibitory

How do we know which neurons to prune (apoptosis) or which connections to prune (synpatic pruning)?

- if a neuron is going to a specific target and it is late: kill it = apoptosis - if there is a more efficient synaptic pathway, why keep the less efficient one? (Synaptic pruning) this is based on the feedback from which ones are actually used and the "use it or lose it" principal

Process of male differentiation of gonads (testes)

- if there is a Y chromosome, there is a region that is called the sex determining region of the Y chromosome (SRY gene) - if this gene is present and expressed it will create a protein called testes determining factor which takes the undifferentiated set of gonads and lets it develop into the testes for male development pattern - this means there needs to be a specific gene (SRY) and protein (testes determinig factor) for male differentiation of gonads

What are examples of genetic modification approaches

- knock-in or Transgenic Models (usually in animals) - knock-out Deletion - Optogenetics - CRISPR-CAS9 Gene Editing - Retroviral gene therapy

what is not allowed in the blood brain barrier

- large molecules (like the triptan blue dye) - non lipid soluble molecules - highly charged molecules - potential neurotoxins are filtered out usually - many drugs are also usually filtered out (we could develop the best medications but if it can't cross BBB, it can't be used)

oxytocin receptors and pair bonding in the voles

- looking at the density of oxytocin receptors in the prairie vs montane vole - oxytocin is released a lot during orgasm, dark spots = this oxytocin - the prairie vole has a much higher density of oxytocin receptors which is associated with forming a social bond, allowing it to have more impant on the brain and therefore behavior "oxytocin" = cuddle hormone/love hormone - also associated with the bond between parents and children (not just romantic) - they both release a lot of oxytocin though

what things are males better at? what things are females better at?

- males (higher levels of testosterone) have a slight advantage in visuospatial tasks (relationship between objects and how they fit together), whereas females (higher levels of estrogen) have a slight advantage in verbal tasks (early in life, better language acquisition, better vocab) - this is linked to the current levels of testosterone/estrogen (activational) NOT prenatal

sexual orientation and visuospatial tasks

- males perform better than females on visuospatial tasks, regardless of sexual orientation - heterosexual females < homosexual/bisexual females < homosexual males < bisexual males < heterosexual males which outperform everyone else - homosexual and bisexual females scored about equally, outperforming heterosexual females (who did the worst)

Function of CSF (cerebrospinal fluid)

- mechanical/immunological protection (wash out waste products) - nutrition/excretion - regulation of cerebral blood flow (regulates blood pressure/flow) - buoyancy/cushioning to the brain so it "floats" in the pool of liquid rather than compressing itself, some protection for minor trauma - moves in pulsifying manner throughout CSF system with ZERO NET FLOW (as more is made, it is put back in blood)

What makes a critical period? (Hypothesis)

- myelination: it might coincide with the bursts of myelination, maybe in a particular pathway connecting one region to another at just the right time where it has the most impact - neurotrophins: the amount of neurotrophins as there isn't a constant supply. If there are more then it might be a time where more neurons are more able to survive/thrive b/c there's a lot of neurotrophins at a specific time

6 layers of the cortex showing the radial glia

- neurons move from the ventricular zone outward to the final location near the surface of the brain ("inside out" migration) - layer 6 (deepest, subcortical) to layer 1 (towards skull, very outward) - SO, the radial glia fills up layer 6 first of new cells, then 5, then 4, etc until the last layer is 1 - this is the typical development trajectory - schizophrenia patients do not have a completely even distribution of cells, layer 6 and 5 (inside) have more cells where the outer layers have less cells as the neurons are caught in a traffic jam and can not get through

Environmental toxins: fetal alcohol spectrum disorder

- one of the most frequent preventable causes of developmental disabilities and behavioral problems - the brain of infants who are about the same age is photographed. The one on the left had substantial fetal alcohol syndrome (right = neurotypical) - the brain of the fetal alcohol syndrome was much smaller, there are also differences in the structure where the grooves (convolutions) are almost absent and the brain is much smoother - right now the CDC says there is NO safe amount of alcohol that is safe for pregnancy, however FASD matches criteria of binge drinking (usually in 2 and 3 trimester)

rat brain: hypothalamus

- purple area = represents the size of the sexually dimorphic nucleus of the preoptic area - the size in the male rat is MUCH bigger than in the female - probably related to the androgen exposure from the testes right around organizational boom around birth that the male's experienced. if we were to castrate male rat pups right after they were born: we would not see this SDNPA in the typical male fashion (very large), instead it would be developed in the female fashion (smaller) - HOWEVER, if we gave testosterone later in life (past the critical period) it would not change the sexually dimorphic nucleus, organizational

Bacterial Meningitis (Meningococcal)

- rare, life threatening, antibiotics and vaccinations available, the worst kind

Cerebrospinal fluid (CSF)

- secretion/Made by ependymal cells of choroid plexus (lines walls of ventricles) or the cells in subarachnoid space of meninges - it then flows into central canal of spinal cord and come back so it is in the subarachnoid space, then goes in blood stream at superior sagittal sinus - an adult has about 100-150 mL at any time, replenished 3x/day - similar composition to clear plasma of blood (but NO proteins)

shingles

- something that typically affects older adults - similar to cold sores, it is caused by a virus (varicella, the one that causes chickenpox) - you know it is shingles because it is on one side, unilateral, affecting one narrow strip - it is very itchy rash but that one strip corresponds to the DERMATOME of the specific spinal where the viruses has become activated

CRISPR-CAS9 Gene editing

- technique that we got from bacteria 1. scientists create a genetic sequence that is called guide RNA that matches the DNA they want to modify 2. they add it to the cell with a protein called CAS9 which is from the bacteria which acts like scissors that cuts the DNA 3. then the guide RNA finds the target DNA sequence CAS9 cuts it right out and another piece of DNA is put back in place of the old one and enzymes repair it and make it smooth - this is a technique that has potential to treat many genetically based disorders AND ethical concerns - not well regulated, corporations can do this can be used in humans to cut a piece of DNA and use a DNA repair mechanism to change it, which can change gene expression or change modifier genes in the pathogenesis of disease

Synaptic rearrangement graph

- the brain does not develop in a one size fits all pattern - the peak of synapses in the visual cortex (4-8 months) is earlier on than the peak of synapses in the prefrontal cortex - infant toys are very visually stimulating at this point, with high contrasts patterns/black and white, to capture the newborns interest in this stage. - the amount of synapses in the visual cortex declines around 2 (actually 8 mo-4 yrs) which is around the time when they are walking and gaining depth. It then generally plateaus throughout adulthood (4 yrs-rest of adulthood) - the amount of synapses in the prefrontal cortex peaks around early childhood (1-8 years) early elementary school. They learn about delaying impulses, and learning to follow rules, which are skills that are suited to having lots of activity in the prefrontal cortex. It then drops in later childhood (8-20 yrs) and is flat until we get into advanced age (20-65 yes)

Kleinfelter Syndrome (47, XXY) polysomies

- the most common sex chromosome abnormality (still super rare, 1 in 600) - phenotypic male - external gentialia is the same as a male - small penis and testes, reduced beard growth - reduced fertility - extremelly tall height, some female secondary sex characteristics (those that develop during puberty) such as wide hips and breast growth - often requires testosterone treatment at puberty for masculine traits - intelligence: mild cognitive difficulties (does not generalize across everyone with condition), social awkwardness, delayed/reduced verbal skills in which it may be confused with autism spectrum disorder

young vervet monkeys study

- these monkeys prefer sex typed toys without any human like gender socialization RESULTS: the female monkeys were more likely to choose softer toys, those that required more fine motor or toys that supported idea of nurturing/caretaking male monkeys: preferred toys that were louder, more moving parts/gross motor skills - children as young as a year old-18 months show the preference for sex typical toys even when both types of toys are available

blood brain barrier

- tight junctions between endothelial cells and astrocytes whose swelling end feets wrap around the capillaries: these sweelings creates obstacles/barries so some molecules can not get through which protects brain from foregin substances

what activates sexual behavior in women

- was erroneously linked to testosterone as they completely removed a woman's adrenal glands and her sexual desire was harmfully impacted 1959 (however adrenal glands release a lot more than just testosterone, so this was a problem) - NO OTHER SPECIES shows Testosterone influencing female desire to mate - need more research on ovarian hormones (estrogen) in female sexual behavior now - interesting: as women go through menopause and decrease their production of estrogen that does not negatively impact sexual desire so there is more to the story

sex differences in behavior/cognition

- we are more similar than different - however there are differences

Organizational effects of hormones

- what we have been talking about so far, they occur very early on in prenatal development - they are long term and irreversible (has to do with the sex organs, gonads, the brain, as well as behavioral signs we see) - associated with critical/senstive period: having the hormones allows them to have that effect at aparticular time but if we give those hormones later they won't have that same impact - hormonal effects on the differentiation and development of the sex organs, brain, and behavior in early development

early neural development

-1st week following conception, the human zygote has divided into three germ layers: Ectoderm, Mesoderm, Endoderm -2nd week following conception, the zygote is referred to as an embryo -3rd week following conception, inducing factors differentiate the ectoderm layer into skin and neural plate The developing neural plate forms the neural tube (which becomes our central nervous system, ectoderm)

imprinted genes

-expression determined by contributing parent -both alleles are NOT equally expressed - Genes whose expression is determined by the parent that contributed them - very very early in life

When does the peak number of synapses occur in the prefrontal cortex

1 year of life

Another detailed explanation of apoptosis process

1. Healthy cell lacks the neurotrophin to sustain itself (the fertilizer) which triggers the cell death process 2. The membrane starts to weaken in integrity (called blubbing). It then breaks off into smaller parts due to enzymes 3. We have the macrophages and microglia that comes in and basically cleans up the mess. This is normal and healthy when it occurs within the timing and amount that it is supposed to happen

procedures involving meinges (diagnosing)

1. Lumbar Puncture (spinal tap) used as diagnostic procedure, they suck out the CSF fluid using a huge needle to see amounts of cells, presence of bacteria, etc. very current state as it is constantly replenished 2. epidural, space between the dura and the bone and at the very bottom (caudal) of spinal cord it narrows but there is still a space, local anesthetic applied here to stop action potentials, inhibiting sensory and some motor - has been used during childbirth (contraction pain inhibit, but they can not walk)

circle of willis

A circle of arteries at the base of the brain that supply blood to the brain - near the optic chiasm, like a vascular roundabout so there is a little bit of collateral blood flow so if there was a catastrophic blockage in one of the major arteries then there could be enough flow from other arteries so it could get at least some blood flow to that area of brain

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape. - is a visualization - inside a nucleus, if you extract the DNA on chromosomes and line it up we could match them into their diff pairs (the 23rd is the diff one)

family linkage

Adoption studies: if a trait expression is more similar to adoptive parents vs biological parents Sibling studies: similarities between siblings, are you very similar are completely opposite

congenital adrenal hyperplasia (sex difference)

Adrenal glands release elevated levels of androgens, this results in: Males: few observable effects (this is because the amount released by the adrenal glands is so small compared to the amount naturally released by the testes, not influential) Females: exposed to excessive androgen through adrenal gland which contributes to masculinization of their external genitalia; also correlates with some behavioral differences, born with ambiguous external genitalia Congenital = from birth, adrenal = the glands on top of kidneys that release many hormones, hyperplasia = too much Testes = main source of testosterone in males Adrenal glands = releases androgens like testosterone in both males and females

What does it mean to have elements of both gonads?

All embryos have precursors to both male and female internal organs @6 weeks The fetus has BOTH: - Wolffian system eventually develops into seminal (semen) vesicles, vas deferens, prostate (IF there is the SRY gene and testes determinig factor protein) - Mullerian system eventually develops into uterus, upper vagina, and fallopian tubes in the absence of the SRY gene and protein (this is the default system

an example of a SNP: ApoE4

ApoE4 is found on chromosome 19 - a complicated gene involved in a lot of different things - there are 3 variances: 1. E2, E3, and E4 E2 and E3 are very similar because there is one nucleotide change they are associated with diff codons. these diff codons are associated with diff amino acids E4 variance is considered the risky gene for Alzheimer's. it is not common, it's found in about 15% of population but of these people that have 2 copies of the E4 variance they have a 91% of developing Alzheimer's with average an onset age of 68 yrs - so, having ApoE4 is not a guarantee but if you have two copies of this gene it is considered a much higher risk - also associated with chronic traumatic encephalopathy

dermatome

Area of the skin supplied with afferent dorsal sensory nerve fibers by a single dorsal root that is connected to the spinal cord

What is one of the first signs of Androgen insensitivity syndrome?

Around puberty, and there is a lack of expected menstruation (they have an external vagina)

process of circuit formation

At the end of the advancing immature axon (which is called a neurite) (where it looks like the terminal would be), there is a thing called the growth cone - imagine what it is like trying to walk in the dark, as you shuffle your hands to sample environment in front of you, this is what the growth cone does - the growth cone has similar structures to fingers which are called the filopodia and a feature similar to the palm of the hand which is called the lamellipodia - the growth cone samples the environment for different chemical and molecular signposts that can either be attractant (use grow new neurons over here) or repellant (no, don't grow over here) - these neurites (which still have microtubules for anterograde/retrograde transport) are going to pathfind (like worms) and try and find the best target cells to form functional and meaningful connections

How do axons usually grow

Axons do not typically grow in a jumbled spaghetti mess, - they usually bundle together like wires that all meet together which looks efficient and easier to know which wire goes where - this process is called fasciculation, so a lot of specific pathways may be labeled by "oh! It is this fasicle from here to here" b/c that means it is a bundle of axons together

gene x environment interactions: BPA and the agouti Phenotype

BPA is a compound that is found in plastic products (usually those that costs more than $2 are BPA free bc people go scared from the results) - looking at mice who are genetically identical but are phenotypically different (blonde bigger agouti phenotype vs brown wild type) depended on what their mother ate - if they ate a high diet of BPA then the offspring were more likely to be obese and have yellow fur (the gene is on) - if they ate the standard rat chow then they were slimmer and were the standard brown color (the gene is off) - so it is likely that the BPA could affect the expression of the AGOUTI gene to produce these results (likely that BPA exposure turned on the Agouti gene - has similar traits to estrogen in humans

Differentiation: dorsal-ventral axis

Becaues the overlying ectoderm goes back over where the neural groove and neural tube forms, we see the ectoderm there and it releases a lot of a compound called BMP protein Ventral (towards belly) dorsal (towards back) Dorsal half: sensory neurons, gets a lot of the BMP protein which allows more development of neurons that eventually is classified as having a sensory role (contributes to the dorsal root in spinal cord) - dorsal root in spinal cord Ventral half: motor neurons, get exposed to more sonic hedgehog protein (b/c it is pretty fast) which is eventually differentiates at the motor trajectory (or pathway) We see that in the adult spinal cord the dorsal portion is the incoming sensory information and the ventral portion is the motor outgoing portion

Sex hormones and sex chromosomes

Before the embryo produces any sex hormones, genes on the sex chromosomes produce proteins that influence neural structure and function - outside of the gonads, sex chromosomes effects interact with sex hormones in complex ways to produce phenotypes

What is the way that the brain develops?

Bottoms-up approach - so the hindbrain is going to develop first which is the brain stem and cerebellum

Brain in adulthood: healthy aging

Brain changes in healthy aging exhibit neural decline - we see neural decline (outside of disorder like parkinson's/alzheimer's) in the medial temporal lobe which is the area associated with memory - we see neural decline in executive pathways connecting the basal ganglia and frontal lobes which is associated with the stereotypical behaviors of advanced age

The brain in adolescence leads to what?

Brain in adolescence leads to intense behavior

an example of a SNP: cilantro

Cilantro - there is a genetic variance very close to the genes that are responsible for our olfactory receptors which helps process smell - people sent in their genes for analysis to 23 and me (huge sample size) they did a survey of 25,000 people of European ancestry and about 10% said they didn't like eating cilantro b/c it tasted like soap - they had ONE SNP, one nucleotide, the difference between having an AA/AG and a GG genotype at one section influenced how people like cilantro

areas where the blood brain barrier is already weak or it is already a little open (not a perfect system) is called what?

Circumventricular Organs (WEAK BBB) they are weak b/c we are secreting hormones/etc into the blood supply. these areas include: - choroid plexus (makes CSF) - pineal gland (makes melatonin) - pituitary gland (many hormones, related to puberty, develop) into bloodstreams so it has to have a fairly BBB

Internal sex organs

Collectively called the gonads Gonads in females = ovaries Gonads in males = testes

Experiment using newborn kittens: how early intervention affects the brain organization

Contralateral = opposite side ipsilateral = same side We are looking at cells in the occipital lobe (responsible for vision) and if the cells respond to the same eye (ipsilateral) or the oppsosite eye (contralateral) - they temporarily inactivated one eye, so nothing is wrong with the eye or brain it is just lacking that environmental influence and even when they opened the eyelid back up, it was never able to receive visual infomation b/c it never made the brain connections at the critical period. They only received influence from the eye that was open in the first few days of development. - this data supports the existence of a critical period during which the visual cortex can be modified by experience. This benefited many children from the resulting knowledge that corrective surgery for vision must take place as early as possible

autonomic nervous system (both input and output)

DIVISIONS: sympathetic and parasympathetic FUNCTIONS: involuntary (not purely, b/c we can consciously relax, etc) NEUROTRANSMITTERS: acetylcholine, norepinephrine (especially in sympathetic division) EFFECTOR: widespread: cardiac muscles, smooth muscles, glands, fat tissue throughout torso and abdomen - visceral motor (going to our internal organs, chest, abdomen) (automatic, involuntary) - signals can be stimulatory or inhibitory takes info about what is happening in the heart and sends sensory pathway back into the CNS so we get impulses from receptors go into the PNS (cranial/spinal nerves) in order to get back to CNS

histone modification

DNA may unwrap or be stopped from unwrapping from the histone - the DNA itself can be fairly open/accessible/not tightly wound or it can be tightly wound around the histones - a methyl group (CH3) or other molecules bind to the tails of histones, either blocking them from opening or allowing them to open for transcription (this either stops are allows PROTEIN expression process) - usually TRANSCRIPTION

transcription

DNA partially unwinds and a strand of complementary RNA is made - UNWIND/ UNZIPS the DNA in order to make the complementary strand of RNA

what is a single nucleotide polymorphism (SNPs)?

DNA sequence change at one nucleotide so for example changing an adenosine to a cytosine or a guanine (a single switch) - this one change changes the codon that it's associated with and that changes the amino acid that it is associated with and that changes how the result in proteins are made/fit together/what their shape is - changes one nucleotide out of about 3 billion - one particular SNP in the APOE gene can predict risk for Alzheimer's disease

Diffuse pattern vs more focused pattern

Diffuse pattern = before synaptic pruning More focused pattern = after synaptic pruning (There are less connections/lines between the cells/neurons after) - we have our efficient connections as we do not need redundant connections. If it is not joined to a functional neural network we do not need to keep that particular connection around (goes back to use it or lose it)

Which layer of the germ is the nervous system

Ectoderm

Activational effects of hormones

Effect of a hormone that occurs in the fully developed organism, beginning at time of puberty and are maintained throughout adult life - short term effects and can be reversible - these can be modified by taking hormone supplementation

Organizational/activational effects in rodent sex specific behaviors

FEMALE rodents: not secreting hormones from ovaries when they are born, and stays flat until puberty (post natal day 30) which lasts 10 days. We then see that the ovaries come online and start producing hormones that fluctuates in 5 day pattern (estrous cycle) MALE rodents: around time of birth, the testes are producing a lot of testosterone which has a masculinizing effect, after birth the testes are quiet until puberty. The testosterone is then elevated and stays elevated throughout life Around birth = organizing effects of hormones Around puberty = activational effects of hormones

What is the default differentiation plan of gonads?

Female (ovaries) Mullerian system

When was adult neurogenesis in animals first discovered? What was the study?

First discovered in rodent HIPPOCAMPUS and OLFACTORY BULBS around the 1990s - we found that one of the best ways to increase neurogenesis in animal models is exercise - cells that were associated with markers of neurogenesis were stained in controls and the mice exposed to the running wheel - the running mice showed a whole lot more of neurogenesis

How long are the gonads undifferentiated?

For the first 6 weeks, we see that the fetus has elements of both gonads systems

Neurogenesis (process of neurogenesis)

Formation of new neurons (which includes glia) in Nervous system - originates from cells in the ventricular zone - starts from stem cells which has the capacity to become any sort of cell and then they specialized and differentiating into either the neural or glia path. If it goes to neural path then it splits into interneuron of pyramidal neuron or a different type of neuron. If it goes to glial path then it can split into oligodendroglia or astrocyte or other) - progenitor cells (which are in the ventricular zone) divide by mitosis and create more and more daughter cells as we go (one stays one goes) - cell migration

Prenatal androgens and childhood empathy

Generally speaking, females show a higher empathy score than males (as average) - girls that have less fetal testosterone score higher on empathy - boys that have less fetal testosterone score higher on empathy - Correlation is NOT causation

cold sores

HSV1: herpes simplex virus type 1 (very diff than the genital form) - virus infection of Facial nerve (7th cranial nerve pair) - almost 90% of american population - the virus lives inside the cell bodies of the facial nerve which has a root in the pons of the brain stem, it is usually dormant but there are time where it becomes more active, virus travels down axon and comes to the sensitive skin on lips - stress can cause the cold sores to come back out

Why is L-dopa used to treat Parkinson's disease rather than dopamine?

L-dopa was able to cross the BBB easier than the full dopamine (basically it is a smaller molecule)

4.5% of us adults identify as what?

LGBT - this increase was driven primarily by millennials, 8.2% of whom identified as LGBT - we might be seeing a change in the stigmatization/identification of feeling/being a certain way

Development of external genitalia: female

Labia, clitoris, and outer vagina - no hormones/hormonal activity or proteins required

When is the best time to learnlanguage? What about cultures/societies?

Language: kindergarten Different cultures/societies/global perspectives: college - so foreign language does have a lot of value even if it feels hard at the time

Gender

Learned/sociocultural characteristic of being masculine or feminine - uniquely human side of things Think about a big gender reveal party and it is something pink or something blue lets us know whether it is a girl or boy. Most people do not want to call this a sex party so we call it a gender party.

STUDY: prenatal androgens and play behavior

Looked at people with that cogenital adrenal hyperplasis (adrenal glands releasing more prenatal androgens) - typically developing boys are exposed to 2.5 times more androgens as developing girls - girls with that congenital adrenal hyperplasia are exposed to about half the amount of prenatal androgens as typically developing boys (about 25% more than typically developing girls) - boys with that congenital adrenal hyperplasia are exposed to more prenatal androgens BUT there is a ceiling effect where it is not influential compared to the naturally occuring in developing boys

Prenatal androgens, orientation, otoascoustics

Looks at the sexual orientation and the otoacoustics - all the men (hetero/homo/bisexual) had relatively the same number of SOAEs - the women are all higher than the men as a group BUT heterosexual women have the highest number where homo/bisexual show a slightly more masculinized pattern - it is interesting to note that in this study the bisexual women were between the heterosexual females and the more male typical pattern - correlation is NOT causation - these have been factors in determining orientation but are certainly not the only ones (b/c we can not do true experiments, correlations are the best we have)

Mesoderm

Middle layer - becomes connective tissue such as ligaments, muscles, blood vessels, and urogenital system (circulatory system, think about lots of the tubes of our body)

Parasympatheic nervous system (output)

NEUROTRANSMITTERS: acetylcholine - has 2 different neurons involved here that release the ACh (whereas SNS only has one synapse) - rest and digest - conserves energy, decrease heart rate/blood pressuse - constracts pupils (make smaller) - DIGESTION becomes a PRIORITY - promotes "housekeeping" functions during rest - signals can be stimulatory or inhibitory - seesaw with the sympathetic

does all of our DNA go to make proteins?

NO - there are sections of DNA that are called exons that are coding sequence - there are also sections that are called introns

Brain in adulthood: neurogenesis

Neurogenesis (new cells in adulthood?) - possible roles in adult learning and forming new memories - decline of neurogenesis is associated with cognitive decline (when we stop making new cells, we notice cognitive decline) (which is found in animal models) - multiple reserves help resist loss of function (lots of work in animals that suggests that neurogenesis may be one of the ways for things like antidepressants to gain their effectiveness)

Do personality traits generally correlate with prenatal hormone exposure?

No, personality traits do not often correlate with prenatal hormone exposure - BUT empathy is an exception, where we see that correlation (less testosterone = more empathy) however, correlation is NOT causation

abnormalites in dendritic spine density and neurocognitive disorders graph

Normal: forming synapses/going through neurogenesis (line increases in childhood), then normal period of pruning in adolescence (line goes down), so adults have less dendritic spines/synapses than someone in elementary school (which means we have more efficient synapses) pretty stable in adulthood and maybe slight decline in advanced age Autism spectrum disorder: we see more dendritic spines in childhood which are not necessarily all healthy (more skinny), there is pruning in adolescence but not at the same level that we see in neurotypical individuals. Overall, they show more dendritic spines than a neurotypical person. Schizophrenia: they track normally until adolescence. Pruning is exaggerated in those that go on to develop schizophrenia. The number of dendritic spines is substantially lower throughout adulthood in individuals with schizophrenia. Alzheimer's disease: is neurodegenerative so we do not typically see symptoms until much later in life and so it shares the same line as a normal person, UNTIL late adulthood where we see a decline in the number of dendritic spines and the number of healthy synapses - this paints a picture that it is not a place but actually a process that is dysregulated in these neurocognitive disorders

neuropeptides: oxytocin

OXYTOCIN: neurohormone secreted during child birth, lactation, promotes pair bonding - expressed more by FEMALES - released during orgasm by both sexes - Research to see if it is correlates with empathy, a nasal spray of oxytocin to see if they are nicer to others or autism to see if we can help theory of mind (perspective) - if you look at a mother's oxytocin levels before she gives birth you can tell how much time she will spend staring at her infant (more oxytocin = more bond) - love, caretaking, nurturing

Neural tube defects that contribute to disorders of brain development

Occurs during embryonic development - Microcephaly is a very very small development of the rostral (head) end of the neural tube, basically the brain fails to close - Anencephaly is when the rostral end and basically the brain does not develop (brain tissue does not develop - Spina Bifida is a problem at the caudal (tail) end of the neural tube

Myelination occurs where? 2 week? 1 year? Adult? What do we use to get these brain images?

Occurs in the rostral (towards head) direction starting with the spinal cord, then the hindbrain, midbrain, and forebrain (bottoms-up) - very extensive early in life, but is not completed until young adulthood - using DTIs (diffusion tensor images) which show us the pathways of where axons are, we see the axons are present in 2 week infant, but in 1 year they are much more extensive and elaborate, when we are an adult we see a lot more organization/myelination of these white matter pathways - if u see the picture it starts inwards and through time expands outwards

Myelination occurs when

One of the last processes of development to complete and may be happening right now in traditional students (adulthood)

Without the SRY gene, what do the gonads become?

Ovaries (female is the default)

Are cranial nerves part of the CNS or PNS?

PNS (except CN2) - the cranial nerves are part of the PNS with the exception of the optic nerve (cranial nerve II), along with the retina

Identical quadruplets study

Probability: one zygote split TWICE, very very rare" Janane quadruplets" = troubled birth b/c there were four of them - they were identical, but their heights differed, - as the ladies grew up they ALL showed signs of schizophrenia which supports the genetic contriobution to this disorder - even though they all had schizophrenia, they had different forms of the disorder. 1. One was so severe she basically had to be institutionalized 2. Another one was minimally impaired and was able to have a job/marry lead a relatively normal life Interesting case study to see identical genes with some different trait manifestations

The brain in adolescence

Puberty begins a period of cortical thickening followed by thinning (normal/healthy part of pruning process) - we see different development trajectories (like the neurotypical black line in the dendritic spines graph) - (number of synapses) synaptic density reaches adult levels at age 18 in both females and males - myelination continues into adulthood (20-25) with males on the later end of that - the limbic system, prefrontal cortex, and amygdala have immature connections (they are connected but not in the same way they will be as an adult) this might produce "risky behavior" of adolescence (bad things won't happen to me, that only happens to other people) Limbic system = emotional processing amygdala = evaluation of threat prefrontal cortx = decision making - increased amounts of hormones (estrogen/testosterone) which affect the limbic system (and therefore behavior/emotion) as it has receptors for these hormones - generally, adolescents have higher melatonin levels which lead to increased need for sleep (need more sleep in this period of life than others) whereas the mismatch between the amount of sleep they need vs what they are getting maybe starting to be a public health problem for adolescents - "mood swings", decreased levels of dopamine and serotonin lead to these mood swins, sensation seeking, and emotional regulation problems

Are men or women responsible for determining the sex of the child at the end of the day?

SPERM The male as the women always brings an X (She has XX) and the male chooses between X or Y (He has XY)

Genetic sex determination

SPERM Genetic sex determine at the time of fertilization, immediately - depends on whether the sperm that fertilizes the egg caries an X or Y sex chromosome (this is b/c the egg from the mother is always XX) XX = female XY = male Typically 46 XX (female) or 46 XY (male) - sex monosomies (having less than the usual 46, which has one copy of the sex chromosome): 45 X0 (Turner syndrome) or 45 Y0 (no record of this) the 0 means null/blank/missing chromosome - sex polysomies (duplicate/extra chromosome): 47XXX, 47XXY (Kinefelter Syndrome), 47XYY (supermale)

What are the implications of forming connections/synaptogenesis for neurocognitive disorders? - developmental disorders that affect neural growth

Schizophrenia: show fewer than normal dendritic spines in the presynaptic terminals Autism spectrum disorder: have more than normal dendritic spines, but a lot of them are immature (skinny dendritic spines) and are not necessarily going to form a stable neuro connection In the disorders we see differences in either the number of synapses or the relative strength/synaptic maturity Control condition: the dendritic spines are mature and a good amount

Development of external genitalia: male

Scrotum and testes (penis) - 5-alpha-dihydrotestosterone, a specific type of androgen, needed for development of male genitalia; loss results in ambiguous external genitalia - SO, we start with the testosterone and the enzyme 5-alpha-reductase converts it to 5-alpha-dihydrotestosterone

Case of Maria who was born with either ambiguous/slightly skewing female genitalia

She was named as a female, raised as a female, then when she was 12 when she went through puberty - puberty is interesting b/c it does not require the conversion of testosterone into the 5-alpha dihydrotestosterone. It just needs to be testosterone which was being produced normally - by the end of the male typical puberty they were completely typical adult males in presentation Maria —-> Jorge So when the infants are born they appear female, then they go through male puberty - prevalent in a small isolated village in the Dominican Republic where this occurs, they call it the "guave doches" the people who get their testes at age 12 HOW???? - b/c they lack the enzyme, 5-alpha reductase., that converts the testosterone into the 5-alpha-dihydrotestosterone early in development BUT when they hit puberty, the body is flooded with testosterone, the body responds to this and the penis/testes develop/descent - is genetic

What does the ectoderm differentiate to?

Some cells in the ectoderm differentiate to form the neural plate while others differentiate into skin cells - this neural plate then differentiates into 2 additional types. 1. dorsal and ventral halves of the neural tube 2. The second process differentiates the neural tube along its rostral-caudal axis

Caster semenya

South african runner whose sex was challenged in the olympics because she was so fast. The observers complained about her masculine appearance. She had to submit to test in a sex determination lab which was popular after this incident; even if woman passed the nude test. - she is probably intersex/has AIS - Which is a question about competition and what is fair regarding the developmental/chromosomal condition, how does it influence their ability to play (Olympics) having too many or less androgen or transgender - many athletes and fashion models have AIS

How different experiences in different environments can change the dendritic spines: living conditions in rats

Standard condition: free food and water and access to friends in a cage Impoverished condition: free food and water (without friends, which is how the vast majority of studies are done) Enriched condition: "rat disneyworld" there are toys, room to play, friends, food/water Findings: lookings at the complexity of the dendritic arborization, we see that just being housed in the complex environment (the only difference) showed more elaborate dendritic branching AND more spines

process of myelination When does myelination occur? (postnatal brain development)

Starts at 23 gestation weeks (halfway through a typical 40 week pregnancy) - there is a huge burst of myelination right around the time that we are born probably due to the increased sensory input as well as a lot more motor control - occurs in rostral direction, starting with the spinal cord, hindbrain, midbrain, and forebrain - the last area to show full myelination is the prefrontal cortex which is not completely myelinated until early adulthood (20-25 yrs) - We see a sex difference in that females show complete myelination of prefrontal cortex around the earlier end (20-21) where males are at the later end (23-25 )

Postnatal development

Substantial growth occurs after birth: - Increased gray matter - Synaptogenesis - Increased branching of dendrites Increased white matter - Myelination

What is the most common way that people determine the sex of a newborn? How is it done?

The external genitalia If it is done via ultrasound the typical time line is around 18-22 weeks in the pregnancy (out of 40) when there is enough differentiation to confidently and visually determine sex based on the external genitalia

There are some points in prenatal development where the fetus is what regarding neurogenesis?

The fetus is creating up to a quarter of a million new cells per minute (250,000 cells/minute!) - this is neurogenesis

What specifically determines the sex determination

The genetic chromosomes are just one factor in the biological sex determination (There is a range of chromosomes, hormone balances, and phenotypic variants of physical characteristics that detrermine and differentiate biological sex)

Experience dependent change (in the nervous system)

The idea of plasticity = the nervous system's ability to change - the name plasticity comes from the name of a type of clay ("plasticine") which you can mold over and over again to change its shape - long term potentiation, synaptic connections - following injury there is some plasticity, maybe you know someone that lost ability to use one of their senses and showed enhanced use of part of brain responsible for another sensory trait. This is possible but it is LIMITED especially in the brain and spinal cord (CNS) whereas there are more in the Peripheral NS (PNS) - Adult neurogenesis: the idea that we can make new neurons and integrate them into the circuity throughout the lifespan (there is recent research that challenges this)

Phenylketonuria (PKU)

The inability to process a particular amino acid. This amino acid is in lots of things - when a baby is born, it is common to have a heel prick test, take sample of blood, and test it for a variety of diff genetic conditions (PKU is commonly tested right now in newborns) - it is very rare, but it is very mangaeable by avoiding the triggers. The particular amino acid is especially found in things with artificial sweetener (diet coke, chewing gum, common snacks, they have warnings on the packaging of these products)

Turner syndrome (45, X0) monosomies

The individual has one copy of the X chromosome - fairly rare - External genitalia: typically female, phenotypically they present as female, showing typically female external genitalia, - the gonads/ovaries however have structural differents described as streak ovaries - this means there's an excessive amount of connective tissue so they are not able to functionally release the eggs/ova and are not releasing the ovarian hormones - short - so they are infertile - intelligence is fairly normal, have been some reports of spatial relationship/processing of visual cues but this occurs on a spectrum - they typically have high educational and occupational achievement levels (intelligence is normal, lots of variability)

What occurs during the 3 gestational month relating to the gonads?

The male's testes secrete 2 hormones via the SRY gene 1. Testosterone (a type of androgen): has a masculinizing effect that promotes development of Wolffian system 2. Anti-Mullerian hormone: has a defeminizing effect that prevents the Mullerian system from developing While the testes are active/secreting these hormones, the ovaries are not active/not secreting during fetal development

Why are sex chromosome abnormalities important case studys to look at?

The more genes you have the more proteins you are going to make so when we see a typical male or female that is the typical amount of proteins - when we have less than that (turner syndrome, X0 45) or more than that (Kleinfelter XXY or Jacob syndrome XYY) we can almost use that as a way of looking at a dose dependent effect of having sex chromosome genotype on the nervous system and how that influence behaviour - there has been correlations that having less proteins (Turner syndrome) = visuospatial deficits - more proteins (Kleinfelter or Jacob syndrome) = verbal deficits

What is the last area of the brain to be completely myelinated? What does this area do?

The prefrontal cortex which is not completely myelinated until early adulthood - the prefrontal cortex is the follow the rules area, it delays instant gratification, working through goals in a specific way (which is really interesting as to why it is a late finisher) - 25 years of age should be the celebration (instead of 21) of for sure having a mature brain

What is the part of the brain involved in good decision making?

The prefrontal cortex. It is the last brain structure to be completely myelinated

Prenatal hormones and finger ratios

The ratio distance between the fingers - we have hormone receptors in our fingers, and there is a different balance of testosterone (androgen) and estrogen receptors - androgen and estrogen receptors are present on both digits 2 and 4, but more on digit 4 (finger next to pinky) - with higher testosterone and lower estrogen (male typical pattern), we see that the ring finger is longer - with higher estrogen and lower testosterone (female typical pattern) we see that the ring finger is shorter - correlational studies have found that people with diff sexual orientations have slightly diff finger digit ratio - hetero/homosexual males have similar finger ratios whereas heterosexual women have ea greater ratio than homosexual women - homosexual women show digit ratio that is androgynous, more toward the male typical direction, the idea is that this is possibly indicating a greater exposure to prenatal testosterone - correlation is NOT causation

Genetics Disorders that contribute to disorders of brain development

There are alot. Examples: - down syndrome: example of copy number variations in which it exhibits 3 copies of the 21st chromosome, so it is also know as trisomy 21 - fragile x syndrome: has an abnormally large number of codon repeats at a particular site on the x chromosome which is not properly expressed and can create a lot of other developmental consequences - Phenylketonuria (PKU): you have probably seen lots of times and never paid attention to

Why is adult neurogenesis in human in question?

There have been some high profile recent studies that tried to look for this in humans and used verrrrry strict criteria and they did not find evidence in the same way as they do in rodents/animals - for sure/definitely in childhood probably not in adults - more studies with less strict markers/better protocols (looking at it immediately after death without having any lag time) we see some markers suggesting that we might have neurogenesis just not at the same level or same type that we see in animal models - this can have lots of implications of diff mechanisms of diff therapeutic treatments

What occurs during female differentiation to suppress the male gonads?

There is nothing that suppresses the Wolffian system in female development. It just fades away in the absence of the SRY gene

Why is there an asterisk by the "minor risk factor for criminal misbehavior"?

There was a study in a prison population that looked at how many presioners have the specific XYY genotype and they found that it was more prisoners than you would expect based on how rare it is in population - many people were saying "oh we have found the gene associated with criminal behavior" and people started talking about giving these people special "don't be a criminal" classes before they have the opportunity to commit crimes. This is risky/dangerous as you are genotypic people and accusing them of crimes they haven't committed yet So what actually happened? - it was higher than average but the actual number of subjects was really low (9 males). And these males were not in prison for violent crimes as had been reported. They were more likely to be crimes against property (supporting impulse control problems). This is why we do not call it "supermale" anymore b/c of the bad representation/reporting (few decades ago)

Prenatal hormones and otoacoustic emissions (sex difference)

These emissions come from specialized cells in the inner ear that making a sound (not receiving) and are connected to motor - described like making an echo from a sound that occurs in the environment and can be spontaneous (stiffen the muscles and creates perception of sound by other cells in ear) or click evoked (echo that is describes) - females produce a higher number of spontaneous otoacoustic emissions (SOAEs) than males - females produce louder click evoked OAEs (CEOAEs) than males - OAEs presumably indicate the influence of prenatal testosterone levels - correlation is not causation

Why do adolescents exhibit mood swings?

They have decreased levels of dopamine and serotonin which lead to these mood swings as well as sensation seeking and emotional regulation problems - they may respond more than they otherwise would or they may respond less (it is the change in typical regulation that we see)

Differentiation

Think specialization: how does a different location contribute to a different functional role in the nervous system This is the development of more specialized cell types from the stem cell - in the neural tube early on we see differentiation on different directions (dorsal-ventral axis)

What is the cross-section of space between the brain/spinal cord

This space is what was the opening of that neural tube (ectoderm) and has developed a lot more tissue around it. If you zoom in on the ventricular zone we see these dividing cells which comes from a progenitor cell. One of the cells will stay in the zone and one will migrate outwards. KEY THINGS - neurogenesis occurs in this ventricular zone - very fast and furiously: 250,000 cells per minute

germ layers

Tissues in the cells are going to develop into a few different layers called germ layers - Three main layers that form the various tissues and organs of an animal body. - ectoderm, mesoderm, endoderm - think how seeds germinate in order to grow (NOT viruses that make us sick)

copy number variation (CNV)

Too many or too few - a deletion one is missing (the left side of picture where the C is missing) - a duplication is an extra copy (the right side of picture where an extra C is added) Refers to variation in gene structure involving copy number changes in a defined chromosomal region; could be in the form of a deletion where a copy is deleted or an addition (duplication) where an extra copy is added.

What are androgens

Type of steroid hormone that develops and maintains typically masculine characteristics or sexual interest - present in BOTH males and females, there is just a higher dose in males than females - most well-known is testosterone - precursor for estrogen, female typical (as the sex hormones are related on the same metabolic pathway) - typically released from the testes (penis) or can be released by the adrenal glands - these are responsible for the stimulation of bigger, more pigmented hairs around puberty (pubic hair in both sexes, beard)

When does myelination occur?

Until early adulthood

When? Preventing? Observable characteristics? Of microencephaly/anencephaly: Neural tube defects

Very very early in development - best way to prevent these natural neural tube problems is for the woman to increase their consumption of folic acid (found in grain/vegetables) especially if she is trying to become pregnant - microencephaly babies have smaller head sizes. During olympics when brazil was having a big outbreak of the mosquitoes that carry the zika virus (which affects brain development within critical period, is contagious) which has the increased risk of microencephaly - when the rostral (head) part of the neural tube fails to to develop

somatic nervous system

Voluntary, if it involves the muscles it is the somatic NS STRUCTURE: motor neurons, neuromuscular junctions FUNCTION: voluntary motion, things we decide to do NEUROTRANSMITTER: acetylcholine (almost always excitatory to contract) EFFECTORS (where it is going): controls skeletal muscles - Somatic motor (goes out to body, things we choose to do, voluntary) impulses from CNS to skeletal muscles - Initiation to make a movement occurs

Prader scale

Way of assessing the relative masculinity or femininity of external genitalia of newborns - on the left is female typical on the right is male typical - depending on how much androgen levels the female is exposed to, we may see they shift from the female typical to a slightly more masculinized external genitalia (dose dependant)

Difference between apoptosis and synaptic pruning

We can prune the synapses or the connections between the cells OR We can actually prune the neurons and have that apoptosis process to remove the actual cells, not just the connections

What is happening 5 weeks after fertilization of embryo? (embryonic stage)

We can see the sub regions taking shape and forming it - the 3 categories of forebrain midbrain and hindbrain each split into subregions (for a total of 5) - forebrain splits into telencephalon and diencephalon - midbrain splits into the mesencephalon - hindbrain splits into melencephalon and myelencephalon - these layers are formed in the embryonic stage

Results of the previous study

We see that healthy girls spent the most time with girl typical toys whereas girls with CAH showed more of a masculine pattern (playing more with the boys' toys) We see that the boys with CAH spend more time with the typical boy toys than the healthy boys - it is possible that this is an explanation for "tomboys" but there are likely a lot more explanations (or just personal choice)

5-alpha reductase deficiency (condition)

We start with testosterone from testes, 5-alpha reductase is the conversion enzyme that creates the product of 5-alpha dihydrotestosterone - therefore, this is the middle step/enzyme. If we do not have it, we will not have the conversion step as the 5-alpha-dihydro... is the important compound for masculinizing the external genitalia early at birth - Has internal testes, but externally female - during puberty, the body is flooded with testosterone, the body responds to this and the penis/testes develop/descent (puberty is interesting b/c it does not require the conversion of testosterone into the 5-alpha dihydrotestosterone. It just needs to be testosterone which was being produced normally) - fertility to generally normal (varies, maybe a slight reduction but are still able to produce offspring)

Knock-In mice

We're going to take a segment of gene usually from another species Ex: humanized mouse, we take a human gene and inserting it inside the mouse genome so it can become expressed which creates the human version of a specific protein - then we can put these animals into a behavioral task and see how they perform - uses the wild type mouse as the control In = Adding

Spina Bifida (neural tube defects)

When we fail to completely close the caudal (tail) ends of the neural tube - you can see a protrusion that occurs at the tail and happens outside of the body, this requires lots of treatments - it changes the way the fluid flows from the brain, so it is associated with brain problems as well as spinal cord problems (in extreme cases)

Process of female differentiation of gonads (ovaries)

Without the specific gene that is only found on the Y chromosome, the body is going to differentiate and the gonads becomes ovaries - this means that female is the default differentiation plan - much simpler process b/c it i default (XX)

what is the general sentence structure of heritability?

X = X% of the population variation we see in a trait can be accounted for by genetic differences X = any number - most human traits are between 30-60% for these values - the highest ones are for disorders like bipolar and schizophrenia which are high 70 and low 80s saying the range we see may be attributable genetic diff

Is the nervous system "plastic"

Yes, it has much plasticity - it is changing over time as shown by the effects of environmental toxins, genetic disorders, and neural tube efffects on brain development

What is happening when the infant is born in the brain?

You can see all the brain features are there

Example of Genome wide association study

You have a group of patients, you look at their DNA and try and see where all of the small mutations are (disease-specific SNPS) You also have a group of non-patients and you look at their DNA and try and see where all of their small mutations are (non-disease SNPS) - You then try and find a mutation pattern that correlates with the condition/disease/trait of interest

what is the mechanism of action of ApoE4? why is it so risky?

a Knock-in study was performed to answer this question, so they inserted different variances of ApoE4 gene (E2, E3, E4) - the images of the brain were stained for a marker of "tau pathology" which is the protein that held the microtubules together (they witnessed a breakdown of the tau) - they found that the mice that had the knock in of the humanized version of ApoE4 had a lot more tau damage than the other ApoE variances suggesting that the ApoE gene might mediate its risk through increasing the likelihood of that tau breakdown in the microtubules creating the neurofibrillary tangles

Things like forming synapses occur when

a longer process that continues through adolescence but insome ways to adulthood as well

how to induce childbirth

a synthetic form of oxytocin

process of puberty

about sexual maturation and the development of secondary sex characteristics 1. the trigger for starting purberty starts in the hypothalamus, it releases Gonadotropin releasing hormone (GnRH) to signal the pituitary gland (the master gland which can send lots of hormones into the blood supply) 2. once the pituitary gland receives that message, it releases gonadotropins: Leutinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) 3. secretion of sex hormones from the gonads (in females FSH/LH spike to help control menstrual cycle/ovulation in males LH, more stable, activates testes to release testosterone. the FSH and testosterone then cause sperm to mature)

explain what light affects opsin

activates in blue light, opens the channel, you are turning a group of neurons on to see how they influence behavior - yellow light closes that channels and temporarily inactivates a select group of neurons - allows us to ask a lot of the same questions as lesions in a much safer way (light goes right into the neurons)

what is the problem with treating sexual orientation as a dichotomous variable?

alfred kinsley's research (1948, first researcher to study sexual behavior) - created Kinsley scale - he viewed sexual behavior as a spectrum with most people falling on the 0-6 range (does not account for asexuality or others) but is better than the 2 variable (homo or hetero split) that most research puts people into

concordance

almost exclusively from twin studies (especially identical twins) - looking at identical twins and comparing fraternal twins to see if there is a big increase in the similarity between identical/fraternal twins - we are looking for concordance a "match" /they are both expressing the trait or discordance a "disagreement"

coronal plane

also know as the FRONTAL sections - divides nervous system/brain from front to back - usually the nissl, myelin stain in the monkey brain

gene

an individual segment of DNA that produces (or corresponds to) a single protein functional hereditary unit made up of DNA that occupies a fixed location on a chromosome

anterior artery vs posterior artery

anteriorly (front of neck): carotid arteries on either side of the neck posteriorly: vertebral arteries blood vessels that enter brain from back of skull accesses all points of brain

In the CNS, which type of glial cell plays a key role in synapse formation?

astrocytes

lateral

away from the midline ex. my ears are lateral to my nose

knock-out mice

basically a deletion, you are taking out a gene of interest so it is not expressed - then you put these knock-out mice in a behavioral task and see what they can/can't do (to see what happens) - sees how behavior is different when the protein is missing/removed from the expression process - still uses the wild type mouse as the control - Out = removing a normal gene of the mouse has been fully disabled

hydrocephalus

blockage of CSF flow leads to this condition - extremely enlarged ventricles of the head, the fluid is still being made but it has no where to go - treated with shunting surgical procedure where a tube drains the CSF somewhere else (peritoneal shunt would go to gut) (arterial shunt goes to heart, in bloodstream) - can occur in neonates

Dominant, Codominant, Recessive

blue eye color = recessive trait so you need both parents to have blue eyes in order to pass on the allele for blue eyes in order for it to be expressed - a darker eye color like brown is dominant so it would be expressed whether it is homo or heterozygous

how are toys an example of pathway differentiation

brain is plastic - experience dependent connections, if girl typical toys and boy typical toys are the pathways being used then those are the pathways that are going to mature and be kept - for example, someone that is playing with a doll might help with pathways involved in empathy/caretaking/emotions but if someone is playing with a baseball bat that might improve pathways of spatial reasoning and coordination - so even the toys can change the differentiation, it can start the same and differentiate through experience of playing with diff toys - many stores are getting ride of banners like girls toys or boys toys so that it is more appealing to all children (but it is pretty obvious based on color schemes) pink/purple, dolls ex. with legos separating boys and girls where the girls have pink color schemes and a doll to sit in a hottub whereas the boy toys were interactive and moving parts (dynamic play)

DNA methylation

can stop TRANSCRIPTION we are able to change the tags on the DNA but we are not changing the DNA sequence - transcription of DNA into mRNA may be enabled or blocked - Methyl groups bind to the CG base pairs to block transcription - the methyl groups act as a STOP SIGN, stopping the transcription from that point The addition of methyl groups to bases of DNA after DNA synthesis; may serve as a long-term control of gene expression.

Gene silencing by noncoding RNA

can stop TRANSLATION similar to mRNA modification in that it can be a physical barrier preventing the ribosome from going forward and continuing process or it can move out of the way to allow that unblocking (mRNA translation may be enabled/blocked) so this is what happens: - ncRNA binds to the mRNA preventing translation

caudal or posterior

caudal: tail end of four legged animal posterior: back of brain horizontal

what is a key difference between heritability and concordance?

concordance- specifically about data from twins heritability- is about variability in the entire population

lots of things are what?

contralateral - your right hand raising is controlled by the left motor cortex (that crossing over, X)

what is the order of spinal nerves

cranial cervical thoracic lumbar sacral coccygeal for a total of 31 pairs

Parasympathetic division spinal nerve regions and lengths

cranial, sacral 1st synapse: (FASTER). long, lightly myelinated, acetylcholine 2nd synapse: short, unmyelinated, acetylcholine NO ganglion chain

how does meiosis increase genetic diversity

crossing over event and by independent assortment - cell division that reduces the number of chromosomes in half in the reproductive cells

males meaning

current testosterone levels (activational)

Are humans haploid or diploid?

diploid, so we have about 6 billion nucleotides

afferent nerve

dorsal sensory body to CNS

spinal nerves and dermatomes

each of the 31 spinal nerves is responsible for the sensory input and the motor output of a specific dermatome - spinal cord segments are interconnected - allows for complex coordinated movements

What germ layer is the neural tube formed from?

ectoderm - Following gastrulation, a section of the ectoderm folds inward, creating a groove that closes and forms an isolated tube

the human genome

entire set of all of the instructions for constructing a human being - so the instructions for an earthworm would be called the earthworm genome

puberty effects: estradiol stimulates FEMALES

estradiol stimulates - breat growth - maturation of external genitalia and uterus - changes in deposition of body fat - starting and maintaining menstrual cycle

peripheral nervous system

everything BUT the spinal cord and brain - cranial nerves and spinal nerves is what we will foucs on (but any nervous tissue in body that is not in CNS is in the PNS)

exons and introns

exons: nucleotide CODING sequences introns: - we used to call it "junk DNA" which goes to show you how non important people thought it was - they are noncoding meaning they do not specifically make a protein product but a lot of them are REGULATORY so they might influence how and when other genes work so they are important to the process (NOT junk) - do not encode protein products

what are examples of heritability that are very low? low heritability

explained more by environment - types of cancer., like lung cancer, what kind of toxin your lungs have been exposed to - heritability for having a heart is zero - lead in drinking water is an environmentally based toxin that has phenotypical diff in the expression of ADHD later in life (toxind) - heritability of finger number - identical twins have a heritability of 0

distal

far away from the center ex. injured you arm where if you hurt your wrist that would be distal ex. my toes are distal relative to my knees

Zygote (starting point) leads to what 3 layers?

fertilized egg, that becomes a cluster of cells known as a blastocyst, once you start seeing a little more of division of cells there is a clump called a gastrula which has layers associated with it - these layers are the ectoderm, mesoderm, and endoderm - a zygote = cell formed by two merged reproductive cells

horizontal plane

flat crosswise plane - aka axial, transverse - divides brain from top to bottom - least common view

how are neural cells produced

from the mitosis of neural or glial progenitor cells in the ventricular zone lining the neural tube

During puberty for adolescents, there is a burst of new growth that particularly affects the ____ lobes.

frontal

what does it mean if concordance is higher in identical twins than fraternaL?

generally supports a higher heritability, so a higher of genetics in the trait higher concordance higher heritability

how are genes arranged?

genes are arranged linearly on chromosomes

if heritability is 0

genes play no part in producing phenotypical differences between individuals ex. genes are responsible for building hearts, but there is no variation in the population in terms of the presence of a heart, therefore the heritability for having a heart is zero

If the heritability of a trait is 100%

genetics are completely responsible for the phenotypical difference example: Huntington's disease which is a copy number variation mutation which is related to the more copies that you have (more than 35) you will have the disorder

what is the trend of first age of girl's period look like? why?

graphic ranging from 1820-2000 showing the first menstrual cycle (menarche) - there is a clear downward trend HYPOTHESIS - this may be because we have better acces to nutrition so better able to get the amount of body fat necessary to support growing a child so menstruation can happen earlier - may be because there are more growth hormones in our food supply that causes earlier maturation

what were the findings of the above study

having more stressful life events generally correlates with higher risk of depression - as stressful life events increase, the three lines spread out more & more - having LL is considered the most resilient, this does not mean you will never have depression but it means you are less likely to than others - having the SS gene seems to be more risky, this is not a guarantee that you are going to get depression because It is all about the interaction with stressful life events but it is a higher risk than the SL, or LL another study looked at how much bullying and emotional problems at 12 - regardless of genotype the amount was raised as bullying became frequent BUT those with the SS version of the serotonin transport gene were the most affected by the gene by environment interaction

what does puberty help form?

help us develop our secondary sex characteristics

heritability of intelligence

heritability asks what is the RANGE of GENETIC CONTRIBUTION on the bell curve in the POPULATION bell curve is DIFFERENT (not the ability to say 79% of John's IQ is related to the IQ of their parent's)

what is something that shows high concordance and low concordance

high concordance (they are both expressing the trait): height low concordance: risk of rheumatoid arthritis does not show as much concordance

hand example of heritability

how many fingers does a person have? 5 is there variability in the number of fingers a person can have? yes so think about the sources of variability, are there environmental sources (sawing fingers off) are there genetic sources (like having an extra digit or having less than 5) - there is both environmentally and genetically sourced variation - if we were to characterize the range that we see, of the people who have different than five (more or less number of fingers) do you think it is more likely explained by environmental (accidents) or genetic? it is more explained by environmental causes than genetic - even though the number of fingers is clearly an inherited trait, the range in the population we see is not determined by genetics as much as environment - SO the heritability of finger number is actually on the LOW side because the environment is a bigger player across the population than genetics is

smell and attraction studies "sweaty tshirt study"

how smell can influence our attraction - there have been many variation but most they have male participants who wear a basic white shirt for at least 3 days they are not allowed to shower, use deoderant ONLY natural body odor - then female participants smell the sweaty shirts and rate in terms of attractiveness - some were better than others, they then did a blood test and looked for MHC genes (major histocompatibility complex) which is an immune system recognizing factor, better to mate with someone who has diff MHC genes as you for better defense againt infections RESULTS: they found that the shirts they ranked the best, they had the most diff MHC genes than the males the shirt came from - they got siblings, in which when a women smelled her brother's shirt she ranked it as the worst one as this is close MHC genes (some have argued this is a defense against incest, if your genetics are too close to another's)

mutation example: sickle cell trait

if someone has sickle cell trait they may have sickle cell anemia which means their red blood cells have the appearance of a sickle/crescent and this affects the amount of oxygen carrying capacity for each blood cell as well as its ability to clot (more likely to cause clots) normal: a little donut/spaghettio negative/harmful effects: poor oxygen capacity positive/helpful effects: protection against malaria

when is a good time to use retroviral gene therapy?

if there is a lack of protein production - you are able to regulate/improve that through diff types of therapy - lots of viruses have this capability

inferior or ventral

inferior: toward the belly ventral: lower in brain vertical

Meningitis

inflammation of the meninges that protect the brain - when meninges become infected it is right on top of the brain, which causes swelling and compresses the brain tissue which contributes to the neck symptoms - symptoms: close to the flu to the next level (fever, headache, but also neck pain and stiffness, also may show photophobia)

Where is the genetic information stored?

inside the nucleus, in chromosomes in the form of DNA (it has a double helix structure)

why is the brain greedy?

it is 2% of total body weight but uses about 15% of our total blood supply.

process of menstrual cycle (hypothalamus)

it releases signaling molecules to pituitary gland so we have moderate, high, and low amounts of GnRH which drives some of the hormones released from the pituitary, so high releasing GnRH factor = more pituitary released LH & FSH hormones = peak in ovarian hormones, especially estrogen, which causes the egg to develop and allows ovulation to occur (where fertility is most likely) - this is regular/predictable fluctuation of hormones that influence behavior

Filopedia

long, fingerlike, extensions from gowth cones of neurites - this is the area that has most of the sensors for the molecular attractants or repellents

behavioral genetics approaches: family linkage

looks at family studies: "what is the level of genetic relatedness, how does that result in similar traits" - comes from twin studies: ex. "Minnesota study of twins Reared Apart" but there has since been laws that say that twins must be raised together (not split up in Foster care) - they found differences in monozygotic (identical) and dizygotic (fraternal) twins - monozygotic: some traits are very correlated, like height but other things like social attitudes /religious correlations were very minimal so we can see that the higher correlation between identical twins the likelier that there is genetic involvement

family linkage study

looks for when a trait is expressed and when it is not in related family members - and then trying to find that common genetic region that is associated with the mutation between the affected and non-affected family members good: pretty small pool of data, usually restricted to one family or.a small group of families to help generate a hypothesis - shaded region, MUTATION, biological hypotheses

amino acids

made through translation (putting RNA into ribosomes) - when the amino acids combine in diff ways they create complex proteins

almost all anatomical images, especially of brains, are from what subjects?

male brains, we have seen this bias for a very long time

are sex linked characteristics more likely to be expressed in female or male offspring?

male offspring

sexiest man/woman alive

men: a lot more arms/upper torso, muscles, harder features women, softer, face focused, hair blowing

genetic mutations

mutation does NOT necessarily mean bad, there are some mutations that have a net zero effect (neutral), some are very helpful for the reproduction/ survival of an individual or a species, some are harmful and cause cause health/behavioral consequences - can occur spontaneously or in response to something that happens that is called mutagenic in the environment like radiation (CAT scans, too much UV radiation from the sun is a mutation risk), chemicals, or other mutagens - average human baby Is born with about 130 new mutations (genetic sequences not inherited from either parent) the vast majority is not noticeable/are neutral (but there are cases where the eye color is a mutation) - there are positive, neutral, or negative/harmful effects of mutations - they can be specific (affects one subtype of cell) or really widespread - heritable alteration of genes

What are the major things occuring prenatally

neurogenesis, migrating, and differentiating

neuropeptides: vasopressin

neurohormone also important for social behavior, sexual motivation and forming a complete pair bonding - typically expressed by MALES

If a person has a disorder that has a heritability of 1, then the person will suffer from the disorder.

no absolutely not

lumberjack finding

one study showed that physical activity is one way to increase testosterone (like exercise does to neurogenesis) - something really vigorous/cardiovascular activity seemed to increase it by 30% - BUT chopping wood seemed to increase it by 47% hypothesis - when someone is chopping wood 1. it is a physically demanding task 2. provided warmth/supplies for the family

astronaut twin study

one was kept in earth and one was kept in antigravity environment (in space station for about a year) - they then looked at epigenetic markers (methyl tags) between the two and how they changed from being on earth compared to being in space

saggital plane

parallel to midline - midsagittal section, divides brain into two relatively equal halves - right down the middle, slice in half so you can see from the side - most frequent, shows structures right in the middle (medial to lateral view)

what is interesting about symmetry in attraction

people find symmetrical faces more attractive EVEN if they can't articulate why ex. brad pitt (fibonacci sequence)

voles

prarier vole: sweet, loving, gentle, stick around to help raise family, loyal, a monogamous mating system mountain volue: hit it and quit it, rather date and mate with as many females as possible,m promiscuous what is the difference? oxytocin receptors! - you have the female/male voles mating - 3 chambered social task: in one: the familiar partner, new female and asking where does the male spend his time? - the prairie voles spend more time with their familiar partner, they have a bond - the montane vole spend the most time in the middle by themselves, and they spend the less time with the key partner

genetics research tools

probably the latest/greatest innovations ahead exploding our knowledge in this field

angiogram

radioactive tracer in blood to visualize the vascularization throughout the brain - useful for looking for an aneurysm or stroke * stroke events that usually occur are much smaller in smaller blood vessels (rather than the anterior/posterior arteries)

nurture effects gene expression

rats can be categorized as neglectful or super involved caregivers - they show involvement by licking/grooming their pups and we can quantify that and see how that relates to epigenetic changes - looking at diff nurturing conditions and looking at the amount of receptors in hippocampus that are responsible for shutting down the stress response (glucocorticoid receptors) RESULTS: the pups that had high nurturing mothers had more glucocorticoid receptors than the animals that received more neglectful care and those that had more care early in life are more likely to respond to stress better as they are adults (able to calm down faster from stressful circumstances) so very early life experience can change the expression of a gene which will influence adult behavior

what are sex linked characteristics

recessive genes on one X chromosome that are not duplicated on the Y chromosome will be expressed in male offspring - because females have 2 Xs they have a "backup copy" whereas males only have one so if they have the trait it is more likely to be expressed

Sex hormone synthesis

related to the different catecholamine neurotransmitters and how we started with L-DOPA, dopamine, norepinephrine, to epinephrine on the same pathway. Sex hormones follow a similar pathway.. All sex hormones come from cholesterol. 1. Cholesterol-->Progesterone (called a female hormone) 2. Progesterone-->Testosterone (Androgen) 3. Aromatization necessary to convert testosterone into estradiol 4. Estradiol-->Estrogens ***Males and females produce BOTH androgens and estrogens (but differ in amounts). SO, we see that some of the male typical and female typical hormones are required to make other of these hormones

what is a research design that could be done to measure hormonal treatments in adults to see effects

research design with male to female or female to male transsexual individuals before and after hormonal treatment. opportunity for within subjects design where we see if the effects hold true before, during, and after hormonal treatment (b/c it is an activational) RESULTS: - estradiol levels correlated with activation in language centers (better performance on verbal tasks) - testosterone levels correlated with activation during spatial tasks This supports that it is the current levels (activational) that matter most (not organizational)

rostral or anterior

rostral: head end of four legged animal anterior: front of brain horizontal

Radial glia cell trajectory regarding schizophrenia

schizophrenia patients do not have a completely even distribution of cells, layer 6 and 5 (inside) have more cells where the outer layers have less cells as the neurons are caught in a traffic jam and can not get through

gene x environment interactions: serotonin transporter gene, stress, depression

serotonin transporter is the presynaptic auto receptor that allows reuptake to happened brings serotonin back into the presynaptic terminal - has more of a codominance effect - 2 alleles: short, long SS, SL, LL - emotional problems in response to stressful life events or frequent bulling - looking at the interaction between having certain genotypes of the serotonin transport gene and what happens environmentally later in life - a 2003 study of x axis: stressful life events y axis: various dependent measures indicating depression/depressive like behavior

what behavioral traits do sex chromosomes have associated with them?

sex linked characteristics

common spinal nerve conditions

shingles heart attack

When women are ovulating they...

show more interest in sexual behavior (makes sense in evolutionary way as this is when fertility is highest) - some studies show that women will have a diff preferences for how masculine in appearance is of a potential mate based on where they are at in their cycle or if they are taking hormonal contraception (strong vs soft jaw line, facial hair, classically masculine)

identical twin study 3 years old vs 50 years old

shows where the methyl markers are, the yellow represents the overlap red and green show the tags in different places, this suggests that there is a lot of diff in the epigenetic tags so even though they started with the same DNA sequence but over time thru diff environments and choices we see these epigenetic changes compounding over time to where they are more and more diff

what is an example of how traits do not necessarily have a plan but they can be advantageous in one environment and harmful in another?

sickle cell trait very harmful at high altitudes where there is less oxygen available (like Denver) helpful if you are in a tropical area where there are lots of mosquitoes, this would be a survival advantage (they have protection against malaria) - is positive or negative depending on context

What protects the brain?

skull, meninges, cerebrospinal fluid

sexual orientation

stable pattern of attraction to members of a particular sex - not the same as sexual behavior or fantasy - not purely dichotomous (separated into 2 variables, one category or another) there is not much research in this area

Since neurogenesis starts in the ventricular zone, what occurs for neurons to spread? (process of cell migration)

step 2 of neural develop. Cell migration (otherwise they would clog and start traffic, so we must have a way to move them out to the rest of the brain) - guided by radial glia - cells in cerebral cortex arrive in an inside-out fashion (start with an inside close to the center to an outside out towards the outermost parts of the brain trajectory)

process of Differentiation: rostral-caudal axis

step 3 of neural development (neural develop) - neural tube differentiates into 2 directions Rostral (towards head) caudal (towards tailbone) anterior-posterior so it is vertical direction - the key mediator is a group of genes called the Hox genes first discovered in the fruit fly - in the embryonic state the fruit fly has a very segmented body plant (like all insects) it was found that specific genes were coding for what was going to happen at that segment which correlates to what we see in humans: so we have a segment for the spinal cord, we have a segment for the myelencephalon, mesencephalon, diencephalon, and telencephalon, as they develop in sequence

how do we form meaningful connections (circuit formation and synaptogenesis)

step 4 of neural development - a growth cone is at the neuromuscular junction (approaching the muscle fiber) when it makes contact with the fiber it gets feedback. - the growth cone releases neurotransmitters and these chemical messengers say yep this is a good spot you should land here - we see as the growth cone matures, it looks more like the classic synapse we usually see. Once they finally reach the destination to the correct receptor, it establishes these new synapses - so synaptogenesis is the process of forming a meaningful/functional synaptic connection where chemical messages can be exchanged

what causes apoptosis?

step 5 of neural development Programmed cell death (-ptosis = falling, greek for the falling of leaves) - is fairly normal/healthy/important - several factors that can contribute to this. As neurons are growing/surviving there are compounds in their environment called neurotrophins (troph = to grow) which influence neural survival - neurotrophins is like an example of fertilizer in that it is needed to survive and thrive but is a scarce resource and there is competition for it - some neurons have good access to the neurotrophins and they survive. Those that do not have access (either they are too late or they are not at an efficient target) we see the programmed cell death take place

Synaptic pruning

step 6 of neural development This is similar to the apoptosis idea - think of rose bushes, which are high-maintence plants and in order for it to be healthy in the following year you must cut down the branches in the fall so it doesn't freeze. This cutting back process so it can be better later is the idea of what pruning is! - remember when we said we are making 250,000 neurons a minute? That is way too many, if we keep that up we will have way more than we end up with as an adult - like a hair cut, reduces the number of functional synapses. This is influenced by the competition for neurotrophins, if the neuron(ite?) reaches the target that has more neurotrophins it is more likely to be maintained, whereas if it has less then it is more likely to be thrown away. - this goes back to the "use it or lose it" principal which means that synaptic pruning is not only influenced by the competition for neurotrophins but also the amount that the synapses is used (functionality of synapse) - instead of the idea of connecting to everything (which we do in the early path fighting) we want to have the best/most efficient synapses

What do gonadotropins do? (Leutinizing of Follicle stimulating hormone)

stimulate the gonads (either ovaries or testes) which allows the gonads to secrete different sex hormones - in females FSH/LH spike to help control menstrual cycle/ovulation - in males LH, more stable, activates testes to release testosterone. the FSH and testosterone then cause sperm to mature)

Medial

structures close to the midline/center ex. my heart is medial to my arms

Vasovagal syncope

sudden drop in heart rate and blood pressure and the vagus nerve does not like that, and low BP means we can't fight the gravity to get to our brain, leading to fainting b/c if you are laying down gravity is on ur side. often in reaction to a fear inducing stimulus, like blood. - professor has this - not fear based, a physiological response that is common - 10th cranial nerve pair, vagus

Bell's Palsy

temporary paralysis of one side of the face - inflammation/infection of facial nerve (7th cranial nerve pair) - strictly motor whereas stroke there are other impairments

what activates sexual behavior in men

testosterone is activational - linked clearly to desire/interest/libido

when is testosterone lower? when is it higher?

testosterone is lower in older men, those in long term relationships and following the first few months after the birth of a baby - testosterone increases in anticipation of sports/fans in competitions, further increase in winners (decrease in losers)

puberty effects: testosterone stimulates MALES

testosterone stimulates: - muscular development - maturation of external genitalia (penis) - lots of facial and body hair, receding hairline on the head (baldness) - enlargement of the larynx (deeper voice)

process of apoptosis. In the lack of neurotrophins, what is activated?

the "self-destruct" sequence has started due to lack of neurotrophins 1. The cell death genes 2. This activates a series of enzymes that are broadly called caspases 3. The caspases breakup DNA/proteins that are part of the cell 3. The cell then dies

genotype

the actual genetic information - a person has 23 pairs of chromosomes - a person has a total of 46 chromosomes

Heritability

the contribution of genetics to the VARIATION of trait observed in a population - thinking about RANGE not averages - heritability always refers to a population, not individuals - when we are looking at the contribution of genetics that is really one half of the equation:it is implying the role of the environment as well, but we are just quantifying the amount of genetics and saying oh yeah environment is probably the other side/proportion that we are not talking about - Heritability cannot be assessed without taking the environment into account

visual fields are an example of?

the crossing over, contralateral processing where images from the right visual field comes in at both eyes but is processed in the left visual cortex

attraction

the importance of symmetry (on the big parts we are symmetrical, 2 eyes, 2 arms, etc) - degree of similarity of one side of face or body to the other (the more symmetrical the more we are attracted to it) - we like visual features that correlates with having higher rates of fertility/better immune system (back to evolution that we want to have offspring that are numerous, and able to survive) - preference for younger features on FEMALES - preference for masculine men (testosterone related facial features) for causal sexual encounter BUT less masculine men for long term partner - smell preference for an immune system different from our own (dissimilar MHC genes)

Fasciculation

the tendency of developing axons to grow along the paths established by preceding axons - neurites that are growing in the same direction often stick together in this process (a bundle of them together) - a lot of specific pathways may be labeled by "oh! It is this fasicle from here to here" b/c that means it is a bundle of developing axons together - this process is in the PNS as well as the CNS - very efficient, organized, easier to know which wire is where

diagnosement rates

there are different diagnosement rates between males and females (like depression, anxiety, autism) which is probably social cultural - part of this may be hormonal where diff hormonal levels may increase/decrease the susceptibility for diff conditions at diff times

what are the differences in brain structures for men and women?

these are all subtle differences - sexually dimorphic nucleus of preoptic area (hypothalamus of rats) - interstitial nuclei of anterior hypothalamus (humans) (INAH) shows science differenes but they are incredibly small - spinal nucleus of the bulbocavernosus (rats) - thalamus (patterns of connections between white matter especially those that cross hemispheres show differences) - white matter (myelination) of the cerebral hemisphere ****ON THE WHOLE IT IS NOT THAT DIFFERENT

fMRIs in those we love vs those we only like

they put people in fMRI scanner and showed pictures of familiar people in their life and looked at how the activity of oxygenated hemoglobin changed when they were viewing a person they "loved" rather than a person they only "liked" - they found that the areas associated with making good decisions and disgust decrease when we view the person we love

anatomical vocabulary

think as a scale of where to go or find certain things

what are the planned genetic diversity

this entire purpose of this is to give us a variety of traits and then natural selection (those that are favorable for survival of reproduction) are more likely to continue in species (genetic diversity is important and part of our process - crossing over - meiosis - sexual reproduction

candidate gene association study

this has more data than Family linkage study but less than genome wide association study this is hypotheses DRIVEN so if you have a hypotheses from either the family or genome studies, this is more targeted to see if the specific difference is an explanatory factor in the cases versus the controls - Biological hypothesis -> candidate region - the study that compares one or a few genes in a large group of individuals who have a specific trait or disorder with a well-matched group of individuals who do not have the trait or disorder

meningeal lymphatic system

this system connects the brain's immune system, serving with the rest of the brain so it is a clean up/waste removal system meninges around the blood vessels have their own lymphatic system - this has a lot of the cerebral spinal fluid and it can drain into the blood supply while immune cells/proteins drain into the the deep cervical lymph nodes via this newly discovered system

sympathetic division spinal nerve regions and lengths

thoracic, lumbar 1st synapse: (FASTER). short, lightly myelinated, acetylcholine 2nd synapse: long unmyelinated, norepinephrine uses ganglion chain to improve sequence of timing (you don't want heart to beat faster than lungs are able to delive more oxygen)

why is hemophilia so common in the royal family?

to preserve the royal bloodline historically there was a lot of close genetic mating

there are some biases in sex differences are reported in media

today show: brain scans show that women's brains reward being generous, men's brains reward selfishness - they had a stereotype hypothesis that they went and confirmed which is a philosophical problem called "circular reasoning" - "I assume this is true, I am going to gather evidence that supports my assumption"

gene expression

translation of genetic composition into observable appearance of an organism (translation of genotype into the phenotype of an organism)

The more inherited a trait is, the less heritable it is.

true. if the liberal establishment ever gets schools to be relatively equal in terms of facilities, materials, and instructional staff, then the heritability of student achievement would increase. (b/c heritability is the variation!!!)

heterozygous alleles

two different alleles - both alleles are different, one is expressed and the other doesn't affect the organism and the allele that is expressed is dominant

homozygous alleles

two identical alleles for a trait - the same allele for a specific trait

Heritability values

usually on a scale between 0 and 1 - or they are expressed as a percentage of 100% - a low heritability, 0, indicates that most of the variation is not genetic ex. someone exposed to a toxin/poison it does not matter what genes you have if you have a poison in you that causes harm (low heritability) ex. lead in drinking water is an environmentally based toxin that has phenotypical diff in the expression of ADHD later in life - high heritability, close to 1, indicates that genetics explain a lot of the variation in a trait between different people

is this the same object task

usually performed with males/those with higher testosterone levels - males are better at these sorts of tasks

slowing the frog heart's down used which nerve?

vagus nerve

efferent nerve

ventral motor CNS to body

What protects the spinal cord?

vertebral column, it is a small space where the spinal cord comes through

what is allowed in the blood brain barrier via passive diffusion

very small molecules - water - some gaseous neurotransmitters (O2 and CO2) - lipid slouble molecules (prescribed drugs can usually cross thru, like coffee, opiates, hormones, nictotines, etc)

planes of section

ways to visualize material that is not necessarily on the outside or easily viewable - sometimes called slices - different slices gives us views of diff information which has diff uses - how CAT scans and MRIs display visualization of data

Markers of prenatal hormonal environment

we are constrained by ethical constraints to prenatal hormonal manipulation in humans: it is unethical to do any true experimental manipulation in pregnant humans (b/c we do not know the for sure risks/consequences are and many would not agree to that) - sometimes humans have a slightly different response to hormones/use diff hormones than a lot of animal models so this is an area that is hard to do any direct experimentation on either humans or animals - SO we must rely on indirect markers/correlates of prenatal androgen exposure (how much prenatally the fetux was exposed to) THESE ARE: - length of fingers- 2D:4D ratio (second and fourth fingers) - otoacoustic emissions: essentially the sounds made by some of the structures of the inner ear) - correlations in birth order (especially younger males in a family with multiple males seem to have more exposure to prenatal androgens) * the amount of androgens a fetus receives is mostly determined by the fetal DNA (if male = testes release LOTS, in both sexes = adrenal glands release more/less of these prenatal androgens)

when thinking heritability think

what causes the variation of the trait?? (what causes the difference in the trait?) is it genetic (1) or environmental (0)

phenotype

what you can actually see, the observable characteristics - the photo

heart attack

when individuals experience a heart attack, they feel pain in their left arm/left shoulder called "referred left arm pain" - it is a lot more common in males (which is one reason why females may have cardiac events that go unnoticed and more likely to be severe) - the dermatome that is close to the heart does not have a lot of sensory info so the closest dermatome is the one that also corresponds to this portion of the arm

Androgen insensitivity syndrome

when neurotransmitters are released but do not bind to the receptors they are not accomplishing its purpose Similarly, the androgens are being released but there is a problem with the receptors so it is not binding in a way that they have a functional consequence. - these are genetic males, but phenotypic females with (usually) female gender identities - no internal reproductive organs: infertile - rare condition - Since there is no testosterone influence, the Wollfian system does not develop, but the anti-Mullerian hormone is still developed so the Mullerian system does not develop (being suppressed) which results in no internal reproductive organs (infertile) External genitalia - there would be a vagina but it would be very very shallow

translation

when you put RNA into the ribosomes to make amino acids, it then assembles into a group of 3 called a "codon" - different codons are associated with amino acids, these amino acids combine in different ways to create the complex protein RNA instructs ribosomes to produce amino acids

what is different about the 23rd chromosome

you have either the X or the Y - So the genotype for a typically male phenotype is XY - The genotype for a typically female phenotype is XX for that 23rd chromosome

Stages of Prenatal Development

zygote, embryo, fetus

When does synaptic density reach adult levels?

18 years old

cerebral ventricles

4 cerebral ventricles - numbered in order the fluid starts from - appears as empty spaces on an MRI image - filled with cerebral spinal fluid (CSF) - many neurodegenerative disorders are correlated with enlarged ventricles (the conditions are causing the loss of tissues/cells which results in empty spaces that the ventricles expands to fill, is a consequence of loss, not a cause of the condition)

High concordance rate

A high percentage that two people with shared genes will develop the same organic disease.

Genome wide association study

A large-scale analysis of the genomes of many people having a certain phenotype or disease, with the aim of finding genetic markers that correlate with that phenotype or disease. - data-driven - exploratory (not a specific hypothesis) sometimes called a fishing expedition - relies on mutation MAP, creating a big picture overview rather than looking at specific example like the candiate gene approach - takes all the variations in a population and associate that variation with the underlying genes that are generating that variation (find genes contributing to variation in phenotypes of interest) - we are seeing the MOST growth in these GWAS studies, trying to find genes responsible

Process of cells in the sub-ventricular zone early in development

A neural stem cell has self-renewal and can become either potent (they can become anything) or pluripotent (more specialized, can become a few things, like not a stomach cell) Then it becomes a more specialized, starts dividing and we can have our neurons/glias depending on which path the cell's on and which chemical factors are there

What is the control in a genetic study called?

A wild type, the genes of the wild-type mouse are going to make a specific protein

Critical period of plasticity (example?)

A window of time when an experience can have an impactful biological influence (after this time experience has little to no effect) - often talked about in the context of language development and other courses ex. Genie who was locked in a closet for the first several years of her life. She was found/rescued when she was still a child and had almost no language input. Even after decades of teaching, she never really learned language in a meaningful way as she was passed her critical period when the influence of language was important

When does the development of external genitalia occur?

After the 6th gestational week

recessive

An allele that is masked when a dominant allele is present - blue eye allele is masked if the person also has the dominant allele for brown eyes

genome wide association study

BIGGGG data, lots of samples sizes - looks for a specific type of mutation (SNP association) scans as much data as you can get to see where the variant is in a specific trait/disorder to generate a hypothesis - SNP association, common variant, biological hypotheses

Sex

Biological characteristic of being male or female - this apllies to all animals (rats, mice, etc sex can be a variable) - we will focus most on this

meiosis

Cell division that produces reproductive cells in sexually reproducing organisms - this is how egg and sperm cells are fromed

We are also seeing another area with a lot of growth: using genetic modification

Genetic modification uses genetics as an experimental tool to understand how gene expression can influence a lot of different traits

The brain defense (book)

Goes through specific court cases and shows how neuroscientifc evidence is being used in court rooms - the legal definition of an adult is 18, but if someone is 16/17 they can be tried as an adult. - Lawyers/defendents have started using diff approaches in that they demonstrate that their prefrontal cortex was not fully mature yet. So they can say it wasn't their fault and not guilty by reason of immature prefrontal cortex which did not stop them from doing it - most of the general population on a jury is not informed on neuroscience/brain development process so it is interesting to see which evidence is important in swaying how people believe the evidence - DNA evidence's mneaning has only been recently understood as people have recently developed their own scientific literacy (in terms of defining guilt/innocence) - ethical discussions that need to happen

what is haploid

Haploid is the quality of a cell or organism having a single set of chromosomes. Organisms that reproduce asexually are haploid. Sexually reproducing organisms are diploid (having two sets of chromosomes, one from each parent). In humans, only their egg and sperm cells are haploid.

what are examples of heritability that are very high? high heritability

Huntington's disease. celiac's disease, early onset Alzheimer's disease, type 1 diabetes, schizophrenia, bipolar

What is the olympic stance of developmental/chromosomal condition, how does it influence their ability to play

If the athlete identifies as female and would like to compete as female they are allowed as long as their testosterone levels were below a certain limit at least a year prior to the competition If the athlete identifies as male and wants to compete among other males, then no hormonal tests are necessary - they make it clear that they do not require any surgical/anatomical changes as a requirement for participation as it is a violation of human rights

What does the neural tube form?

It differentiates into different regions that eventually is associated with diff regions of the brain The forebrain (prosencephalon), the midbrain (mesencephalon), and hindbrain (rhombencephalon) - the neural tube is the embryonic precursor to the central nervous system - ectoderm

Endoderm

Inner layer - becomes many internal organs, digestion! - our pancreas, thyroid, lung, stomach, intestines

Lamellipodia

Like the palm of hand, flat, sheet like extensions from core of growth cones - think lamination (flat sheet) - we see a lot of mitochondria, a lot of things that keep the cell alive/growing/advancing

What is the purpose of synaptic pruning

Makes the neuron communication more efficient

What are the structures that germ layers form?

Neural plate, neural groove, and neural tube (in order)

How are new neural cells produced?

New neural cells are produced from the mitosis of neural or glial progenitor cells in the VENTRICULAR ZONE lining the neural tube - some daughter cells remain in this zone while others migrate away

Increased amounts of estrogen/testosterone affects which brain area?

The limbic system

What do we see a difference in when it comes to women and men?

We see a sex difference in that females show complete myelination of the prefrontal cortex around the earlier end (20-21) where males are at the later end (23-25 )

allele

different versions of a gene

The heritability of having fingers on each hand is 1 or close to 1.

false it is close to 0

concordance rate

indicates the percentage of twin pairs or other pairs of relatives who exhibit the same disorder

choroid plexus

produces CSF, lines the walls of the ventricles

ipsilateral

same side of the midline ex. right arm and right leg

function of cerebral arteries

the major artiers that get blood to brain (has to do with the cerebral blood supply)