Biopsych Exam 3

Brain Mechanisms for Hunger

Early research suggested that the lateral hypothalamus (LH) served as a hunger center. Rats with lesions in the LH would starve to death in presence of food because they would not initiate eating. Electrical stimulation of LH produces immediate feeding. Doubts about this tho because if rats with LH lesions were force fed, they eventually began eating again.

Hormones and Sexual Behavior

Estrus coincides with ovulation making likelihood of fertilization high. During nonestrus periods, a female will not only reject sexual overtures from males but likely to respond aggressively to his advances. Women's sexual activity decreased following removal of adrenal gland. Led to assumption that adrenal hormones and testosterone were primarily responsible for sexual desire in women. MPA reduces circulating testosterone levels in men to prepuberty levels generally eliminating any sexual activity. Men in stable long term marriages have lower testosterone levels than single men or men involved in many committed relationships had highest testosterone of all. Suggests that being securely partnered reduces testosterone perhaps due to lower levels of competition with other men. Decreases in tes following child birth. High testosterone levels not compatible with pair bonding and parental care and also challenge immune system functioning.

Effects of norepinephrine and glucocorticoids on mem

Extremely intense emotions suppress encoding of declarative memories by hippocampus while enhancing the encoding of emotional components of memory through the action of gluco on amygdala. Stress induced gluco and nor release signals the amygdala to engage the prefrontal cortex, hippocampus, and caudate nucleus in a "memory formation" state. Subsequently nor levels return to prestress state but gluco remain active longer. Gluco initiate changes in gene expression that shift the brain into a memory storage state.

47, XYY Syndrome info

Jacob Syndrome more for males. The boys are in typical limits, although may be somewhat taller and leaner, suffer from acne, and have higher risk for minor physical abnormalities of the eye, elbow, and chest. Average IQ scores slightly below. Language difficulties and autism common. Men with this are fertile but more likely to make sperm with sex chromosome abnormalities Property crimes Criminal and antisocial behavior was more closely associated with lower intelligence than with an atypical genotype Have fewer partners, less likely to become parents, lower income, not as educated (might contribute to antisocial behavior)

Working Memory info

This involves LTP and glutamate receptors Distinguishing between two types of AMPA receptors: GluA1 and GluA2 subtypes. During the initial unstable phase following an LTP stimulus, additional GluA1 receptors are inserted into the postsynaptic membrane. In the later stable phase, the GluA2 receptors become more important. Using genetically engineered mice lacking GluA1, researchers have discovered that GluA1 receptors are required for the initial phase of LTP but not for the later more stable phase which requires GluA2 receptors Rodent working memory can be assessed using a radial arm maze. The task is to find the bait. To do the task efficiently,the rodent needs to remember which arms have and have not been visited. In support of observations made in LTP research, rodents lacking GluA1 receptors made many errors in the radial arm task. the insertion of this receptor is important in working memory.

Development of Gonads

Up until sixth gestational week both male and female embryos have identical primordial gonads that can become male or female Chromosomally male mice genetically modified to lack the SRY gene develop ovaries,whereas females in which SRY gene has been inserted develop testes

interstitial nuclei of the anterior hypothalamus (INAH)

a collection of four small nuclei in the anterior hypothalamus, two of which INAH-2 and INAH-3, appear to be sexually dimorphic. The size of INAH-3 might be associated with male sexual orientation Human equivalent of SDN-OIA,

glycogen

a complex carb used to store energy in the liver

associativity

a condition believed necessary for learning in which the pre- and postsynaptic neurons are nearly simultaneously active

cooperativity

a condition for the formation of LTP in which several synapses onto the target postsynaptic neuron must be simultaneously active

congenital adrenal hyperplasia (CAH)

a condition in which a fetus is exposed to higher-than-normal androgens, resulting in masculinization of external genitalia and some cognitive behaviors in affected females

Androgen Insensitivity Syndrome (AIS)

a condition in which a genetic male fetus lacks functional androgen receptors, which leads to the development of female external genitalia and typically female gender identity and sexual behavior

postpartum depression

a condition in which new mothers may feel very sad, cry a lot, have little energy, feel overly anxious about the baby or have little interest in the baby, and in extreme cases, think of harming the baby

premenstrual dysphoric disorder (PMDD)

a condition in which premenstrual mood changes are unusually severe

premenstrual syndrome

a condition in which some women experience physical and psychological symptoms immediately prior to the onset of menstruation

ultradian cycle

a cycle that occurs several times in a single day

diabetes mellitus

a disease characterized by insulin deficiency, resulting in hunger, excess sugar in blood and urine, and extreme thirst

jet lag

a disruption of circadian rhythms due to crossing time zones

parallel fiber

a fiber originating in the granule cells of the cerebellum that synapses on the Purkinje cells

sex-determining region Y (SRY)

a gene located on the short arm of the Y chromosome that encodes for the testis-determining factor

Major Histocompatibility Complex (MHC)

a gene that encodes our immune system's ability to recognize intruders; might account for preferences for body odors

cholinergic mesopontine nuclei

a group of cells located in the border of the pons and midbrain that use ACh as their major neurotransmitter and participate in the maintenance of waking; Meso refers to mesencephalon or midbrain and pontine to the pons

Cholecystokinin (CCK)

a gut hormone released in response to the consumption of fats that also acts as a CNS neurochemical that signals satiety

ghrelin

a hormone produced mainly in the stomach that increases hunger

cortisol

a hormone released by the adrenal glands that promotes arousal

luteinizing hormone (LH)

a hormone released by the anterior pituitary that signals the male testes to produce testosterone and that regulates the menstrual cycle in females

Follicle-stimulating hormone (FSH)

a hormone released by the anterior pituitary that stimulates the development of eggs in the ovaries and sperm in the testes

Gonadotropin-releasing hormone (GnRH)

a hormone released by the hypothalamus that stimulates the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) by the anterior pituitary gland

growth hormone (GH)

a hormone released during stages 3 and 4 of slow-wave sleep that promotes growth, increases in bone and muscle mass, and immune system function

anti-mullerian hormone (AMH)

a hormone secreted by fetal testes that causes the degeneration of the mullerian system

angiotensin II

a hormone that constricts blood vessels to maintain blood pressure and triggers the release of alsoterone

melanin-concentrating hormone (MCH)

a hormone that interacts with leptin and plays a role in the regulation of eating

antidiuretic hormone (ADH)

a hormone that promotes retention of fluid by signaling the kidneys to reduce urine production and by stimulating the release of renin. Also known as vassopressin

serotonin syndrome

a life threatening condition characterized by hypothermia and muscular rigidity caused by excess serotonin activity due to use of therapeutic or recreational drugs

hyponatremia

a life threatening condition in which both extracellular fluid levels and sodium concentrations in the extracellular fluid are too low

hyperthermia

a life threatening condition in which core body temp increases beyond normal limits in an uncontrolled manner

free-running circadian rhythm

a rhythm that is not synchronized to environmental time cues

sleep spindle

a short burst of 12 to 14 cycle-per-second waves observed during NREM sleep

restless leg syndrome (RLS)

a sleep disorder in which a limb, usually a leg, moves at regular intervals during sleep

REM sleep behavior disorder

a sleep disorder in which the normal rem paralysis is absent

delayed nonmatching to sample (DNMS) task

a standard test of memory in which the subject must identify the novel member of a stimulus pair following a delay

androgen

a steroid hormone that develops and maintains typically masculine characteristics

nucleus of the solitary tract (NST)

a structure in the medulla that processes info from baroreceptors, osmoreceptors, glucoreceptors, and taste receptors

perirhinal cortex

a subdivision of the rhinal cortex

entorhinal cortex

a subdivision of the rhinal cortex, which lies ventral to the hippocampus

C/EBPB

a substance activated by CREB that in turn activates genes related to synaptic growth

renin

a substance released by the kidneys that converts angiotensinogen into angiotensin II

leptin

a substance secreted by fat cells that helps the body regulate its fat stores

activation-synthesis theory

a theory suggesting that dream content reflects ongoing neural activity

threat stimulation theory

a theory suggesting that dreams provide practice for dealing with threats

classical conditioning

a type of associative learning in which a neutral stimulus comes to elicit a response when it is associated with a stimulus that already produces that response

operant conditioning

a type of learning in which behavior is strengthened if followed by a reinforcer or diminished if followed by a punisher

sensitization

a type of learning in which the experience of one stimulus heightens response to subsequent stimuli

habituation

a type of learning in which the response to a repeated, harmless stimulus becomes progressively weaker

nonassociative learning

a type of learning that involves a change in the magnitude of responses to stimuli rather than the formation of connections between elements or events

associative learning

a type of learning that involves the formation of a connection between two elements or events

glucose

a type of sugar found in foods that is a major source of energy for living organisms

long-term potentiation (LTP)

a type of synaptic plasticity in which the application of a rapid series of electrical shocks to an input pathway increases the postsynaptic potentials recorded in target neurons

short term memory

activated memory that holds a few items briefly, such as the seven digits of a phone number while dialing, before the information is stored or forgotten limited capacity between 5-9 items. Lasts up to 15-18 seconds

angiotensinogen

a blood protein converted into angiotensin II by renin

cataplexy

a feature of narcolepsy in which REM muscle paralysis intrudes into the waking state

solution

a fluid containing solutes

interstitial fluid

a type of extracellular fluid surrounding the body's cells

long term depression

a type of synaptic plasticity in which postsynaptic potentials in target cells is reduced

set point

a value that is defended by regulatory systems, such as core temp or a certain body weight

median preoptic nucleus

an area of the hypothalamus that is involved with drinking behavior

zona incerta

an area of the midbrain that participates in the initiation of drinking behavior

protein kinase M zeta

an enzyme believed to support maintenance of a memory trace

anterograde amnesia

an inability to form new memories

melatonin

an indoleamine secreted by the pineal gland that participates in the regulation of circadian rhythms

reflex

an involuntary response to a stimulus

vasopressin

another name for ADH

Personality

Higher empathy in females and higher levels of physical aggression in males Females with CAH show decreased empathy and increased physical aggression

fixed action pattern

(also known as an instinct) a stereotyped pattern of behavior elicited by particular environmental stimuli

mossy fiber

(hippocampus) an axon from the dentate gyrus that synapses on cells found in CA3 of Ammon's horn.

binge eating disorder

characterized by regular bingeing, but do not engage in purging behaviors

declarative memory

the cognitive information retrieved from explicit memory; knowledge that can be declared

episodic memory

the collection of past personal experiences that occurred at a particular time and place

semantic memory

type of declarative memory containing general knowledge, such as knowledge of language and information learned in formal education

apnea

the total absence of airflow for a period of time

information processing models

theories of memory that seek to explain the management of information by the brain, from detection to storage to retrieval

osmotic thirst

thirst produced by cellular dehydration

extinction

in classical conditioning, the process of eliminating the previously acquired association of the conditioned stimulus and conditioned response

unconditioned response (UCR)

in classical conditioning, the unlearned, naturally occurring response to the unconditioned stimulus (UCS), such as salivation when food is in the mouth.

intersex

individuals who exhibit sexual organs and functions somewhere between male and female elements, often including elements of both

maintenance insomnia

insomnia in which the individual cannot stay asleep during the night

onset insomnia

insomnia in which the individual has difficulty getting to sleep at bedtime

transcription

process in which part of the nucleotide sequence of DNA is copied into a complementary sequence in RNA

testes

produce sperm and sex hormone

Narcolepsy info

Results from disruptions in synthesis of orexins. These appear to monitor the internal and external states of the animal and adjust level of arousal required for survival.

Classically Conditioned Fear

Initiated by sympathetic division or autonomic nervous system by way of lateral hypothalamus (fight/flight) or periaqueductal gray (freezing/analgesia) Amygdala important in fear.

gonads

the internal organs, ovaries in females and testes in males that make reproductive cells (eggs and sperm) and secrete sex hormones

Attraction

Young straight men who looked at beautiful ppl have activated areas of brain involved in pleasure and reward including the nucleus accumbens which also participates in addictive behavior.

solute

a chemical dissolved in solution

aldosterone

a hormone that signals the kidneys to retain sodium

CREB

a protein that activates genes that might be responsible for structural changes associated with long term memory

electrolyte

a substance that has broken up into ion in solution

dentate gyrus

one of two major layers of neurons found in the hippocampus

Quiz questions

1. Michael is determined to lose 50 pounds. In addition to looking and feeling great, what else should he expect? -He will feel cooler than he did before in both warm and cold weather 2. Pyrogens influence fever by which of the following mechanisms of action? -Reducing the activity of warm sensitive neurons 3. Which of the following factors contributes the least to feelings of thirst? -feelings of dry mouth 4. The function of angitensin II is to -constrict blood vessels and trigger release of aldosterone 5. The abnormalities associated with hyponotremia occur when -Both sodium and extracellular fluid levels are low 6. Insulin levels -Increase following a meal 7. Low levels of leptin lead to -Feeding behavior, increased parasympathetic nervous system activity, and the suppression of TSH and ACTH 8. Antidepressent medications are -Somewhat useful in treating bulimia nervosa but not anorexia 9. The case of David, who was raised as a girl but later took on a male identity, reminded researchers that -Biology plays a significant role in gender identity 10. Chromosomally male mice that are genetically engineered to lack the SRY gene will develop -ovaries 11. In cases of AIS, the testes release -Both anti-Mullerian hormone and testosterone 12. Masculine play behavior and toy selection among young girls is correlated with -Maternal androgen levels 13. The hypothalamus controls the release of sex hormones by secreting -GnRH 14. You've been in college in Orange County, Ca... -Fly out of LA at 7am PST and get into Boston at 4pm EST for a 1pm meeting with the dean the next day 15. The origin of the SCN's rhythms may be -Oscillations of protein production and degradation 16. EEG recordings during REM sleep are similar to -Beta and theta waves 17. Which of the following structures are active during REM sleep but not during wakefulness or NREM sleep? -rostral pontine reticular formation 18. Richard was diagnosed with major depressive... -dream less than he did prior to taking the drug 19. If sleep is a way to preserve energy, we would expect -Smaller animals to sleep more due to their high metabolic rates 20. A quick, involuntary response that always occurs with specific stimuli is called a -reflex 21. In Pavlov's classic experiments, food served as... -Unconditioned stimulus 22. In sensitization in Aplysia, what processes account for the stronger than normal responses of gill motor neurons? -extended action potentials in siphon neurons...result in release of greater than normal amount of neurotransmitter 23. If you temporarily inactivate the red nucleus, this will prevent -conditioned response but not learning 24. Decreases in EPSPs in cerebellar Purkinje cells is seen in -long term depression LTD 25. Memories of an individual's personal experience are stored in -episodic memory 26. In experiments Wilder Penfield performed on patients, they reported experiential memories when stimulated which region of their brains? -temporal lobes 27. Input from the rhinal cortex travels along -the fornix to hypothalamus 28. Mice with regular LTP -form new maps and can retain them for long periods of time 29. Your great uncle recently had a stroke... -prefrontal cortex

Memory Consolidation

Consolidation requires transcription and translation.

Testosterone

an androgen produced primarily in the testes

ovaries

female gonads the source of ova and sex hormone

isotonic

having the same concentration of solutes as a reference solution

osmoreceptor

a receptor that detects cellular dehydration

glucoreceptor

a receptor that is sensitive to the presence of glucose

hypopnea

a reduction in airflow during sleep

Special Benefits of Sleep

REM sleep is not only mechanism for consolidating new info in memory

fever

a carefully controlled increase in the body's thermal set point that is often helpful in ridding the body of disease causing organisms

ammon's horn

one of two major layers of neurons found in the hippocampus

mossy fiber

(cerebellum) a fiber connecting a neuron in the pons to the granule cells of the cerebellum

Deviations in Human Core Temperature

-Hot flashes in menopause -Fevers due to illness 41 C/ 105.8 F (can actually fight off disease) -Hyperthermia: Failure of compensatory mechanisms (when the body's normal compensations such as sweating and dilating the blood vessels can't keep core temp within normal limits ----Drugs (Amphetamines, cocaine, ecstasy, and some antidepressants MDMA ecstasy (Serotonin Syndrome)) -Heat Stroke: Strenuous activity or heavy clothing in hot environments -Hypothermia (low core temp) Below 95°F; fatal below 87.8°F: pupils dilate, behavior almost drunk, consciousness lost; Cooling counteracts typical neg reactions to an interruption in the blood supply in the brain. Carefully induced hypothermia protects brain from damage but also seems to promote regeneration after injury People with existing infections more likely to get heat stroke during exercise. Many recreational and therapeutic drugs are capable of producing hyperthermia. Can increase production of heat, interfere with heat dissipation or both. Highest risk of serotonin syndrome occurs when medications act as agonists at the 5-HT2 serotonergic receptor

Summary Temp:

-Hypothalamus provides most control -Drops in intracellular fluid volume produces osmotic thirst, which is detected by osmoreceptors located in the organism vasculosum of the lamina terminalis (OVLT) -Decreases in volume of extracellular fluid stimulate the release of antidiuretic hormone (ADH) from the pituitary gland. ADH signals the kidneys to reduce urine production and initiates a sequence leading to increased production of angiotensin II. -Angiotensin II appears to stimulate drinking by its action on the subfornical organ (SFO). Drinking stops in response to receptors located in the mouth, throat, and digestive system.

Endothermic Responses to Heat and Cold

-When our body temp goes down we shiver. Shivering results from muscle twitches. The muscle activity involved in shivering produces heat, but at the cost of a high expenditure of energy. Blood vessels constrict, keeping most of the blood away from the surface of the skin, where heat loss is greatest -Blood vessel constriction that is too extreme leads to Raynaud's disease -If cold conditions persist in spite of shivering, the thyroid gland increases the release of thyroid hormone. Higher levels of thyroid hormone are associated with greater overall metabolic activity which warms the body. In human infants and small animals, the sympathetic nervous system responds to cold by stimulating greater metabolic activity in brown fat cells (have more mitochondria)

Purkinje cells

a cell in the cerebellum that influences the structure's activity by forming inhibitory synapses with the output cells in the deep cerebellar nuclei

Bliss and Lomo experiment

1. A weak stimulus was applied to the perforant pathway and activity in dentate gryus was recorded 2. A strong stimulus was applied to the perforant pathway and activity was recorded 3. A rapid series of stimuli was applied to the perforant pathway 4. Weak stimulus was applied again, but this time it made a bigger response than in step one In other words, experience made these synapses more efficient. The change in responsiveness in target cells after the rapid series of shocks is know as LTP.

granule cell

a cell within the cerebellum that is the source of parallel fibers

Hypnopompic hallucinations

A REM-type dream that intrudes into the waking state upon awakening

beta wave

A brain waveform having 14 to 30 cycles per second, associated with high levels of alertness during wakefulness

alpha wave

A brain waveform having 8 to 13 cycles per second, associated with less alertness and more relaxation than beta activity during wakefulness

gamma band activity

A brain waveform having more than 30 cycles per second, associated with the processing of sensory input

Klinefelter syndrome

A chromosomal disorder in which males have an extra X chromosome, making them XXY instead of XY. frequent problems with fertility, secondary sex characteristics, and verbal skills

Organizing of sex hormones

A classic view of organization assumes that this process produces permanent changes in biological structures. Much of the time this is based on epigenetics and raises possibility that these changes might be less permanent than thought.

shift maladaptation syndrome

A condition resulting in health, personality, mood, and interpersonal problems resulting from sleep disruption due to shift work

Stress Effects on mem

A fast acting sympathetic nervous system response leads to release of epinephrine (adrenalin) and norepinephrine from adrenal glands into the blood supply. A slower system, the hypothalamus-pituatary-adrenal (HPA) axis, leads to the release of glucocorticoids such as cortisol from adrenal glands. Glucocorticoids freely cross the blood brain barrier and enter the brain to interact with their own receptor systems Epinephrine released from adrenal glands in response to stress (adrenalin rush) can't cross blood brain barrier so instead makes its effects on tthe brain indirectly. First circulating epinephrine binds to receptors on the vagus nerve, cranial nerve X. The vagus nerve wanders far from the brain. It reports back to the brain about the other body systems which then forms synapses in locus coerulus. This is the main source of neurochemical norepinepherine in the brain and makes synapses with hippocampus, amygdala, and forebrain areas. Release of noepi by locus c fibers into amygdala and hippocampus enhances mem formation Events that are stimulating for young rats don't seem as important to old rats, which might result in their forming poorer memories for significant events Being in a stressed state can either enhance or impair memories depending on number of variables, such as the amount of time separating the onset of stress and the encoding of important info If stress and learning coincide, as in formation of flashbulb mem, memory might be enhanced. However stress produces a refractory period during which subsequent info will be more difficult to encode. This effect of timing might protect important emotional memories from interference from the processing of subsequent info that might be less important for survival Stress or administration of glucocorticoids directly before the recall of a memory reduces retrieval performance, particularly for emotional material. Stress or administration of glucocorticoids following retrieval can impair later recall of same material.

climbing fiber

A fiber originating in the inferior olive of the brainstem that forms synapses on the large Purkinje cells of the cerebellar cortex

oxytocin

A hormone released by the posterior pituitary that stimulates uterine contractions during childbirth and milk ejection during breastfeeding. participates in social bonding, including romantic love and parenting behavior

Schaffer collateral pathway

A pathway connecting CA3 to CA1 in Ammon's horn of the hippocampus

perforant pathway

A pathway made up of axons originating in the rhinal cortex that form synapses in the dentate gyrus of the hippocampus

orexin

A peptide neurochemical produced in the lateral hypothalamus that stimulates eating. Also known as hypocretin

non-REM sleep

A period of sleep characterized by slow, synchronous brain activities, reductions in heart rate, and muscle relaxation

sleepwalking

A phenomenon primarily occurring in non-REM sleep in which people walk while asleep.

estrus

A regularly occurring period of sexual desire and fertility in some mammals

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.

Cellular Basis of Circadian Rhythms

A structure like the SCN can tell time because of the oscillation of protein production and degradation within a cell. The ebbing and flowing of special circadian proteins require approx 24 hours. Research with fruit flies has allowed researchers to identify three separate genes and their protein products that are involved with cellular circadian rhythms. These genes and their proteins are PER (period), TIM (timeless), and CLOCK (for circadian locomotor output cycles kaput). Together, per and tim proteins inhibit the clock protein, whereas the clock protein promotes the production of more per and tim proteins. As levels of per and tim increase, inhibition of clock protein ensures that no further per and tim proteins will be produced. When levels of per and tim proteins drop over time, the reduced inhibition of the clock protein results in increased production of per and tim proteins. Neural activity reflects the oscillation of the levels of these internal proteins, providing a mechanism for communication rhythms to other cells.

evolutionary model of dreaming

A theory suggesting that dreaming provides the advantage of consolidating memories during sleep rather than during waking

major depressive disorder with seasonal pattern

A type of depression that results from insufficient amounts of daylight during the winter months; formerly known as seasonal affective disorder (SAD)

procedural memory

A type of long-term memory of how to perform different actions and skills. Essentially, it is the memory of how to do certain things.

Early Efforts to Locate Memory Functions

Activity of single neurons in patients undergoing surgery for epilepsy corresponded to different types of verbal memories Size of lesion, not where lesion was had an affect on memory //LASHLEY: Mass action- The more cortex you have the better memory is (Not correct tho) His major contribution was that memories are distributed across cortex rather than stored in one location

SIDS info

Africans more likely to die than white and Native American twice as likely to die Boys higher risk than girls Skin to skin care, use of pacifier, avoidance to exposure to smoke and room sharing without bed sharing current recommendations

interpositus nucleus

a cerebellar nucleus thought to be essential to classical conditioning in vertebrates

neural network model

An approach to understanding the function of dreaming as a means for forgetting irrelevant information

organum vasculosum of the lamina terminalis (OVLT)

An area located around the third ventricle in the brain that detects cellular dehydration

ventromedial hypothalamus (VMH)

An area within the hypothalamus that participates in satiety

PGO wave

An electrical waveform observed during REM sleep, originating in the pons and traveling to the thalamus and occipital lobe. Each PGO wave is associated with an eye movement

Estradiol

An estrogen that is a key hormone in girls' pubertal development

transcription factor

a chemical that controls gene expression

Default Mode Network (DMN)

a circuit that is active during periods of unfocused thought

arcuate nucleus

a cluster of neurons involved with feeding located within the hypothalamus

Differentation of of Internal Organs

Anti-Mullerian hormone initiates the degeneration of the Mullerian system. In the female fetus, no additional hormones are needed in this stage of development. Unlike the testes, the ovaries are not active during fetal development. In absence of androgens or anti-Mullerian hormone, Mullerian system will become female. Females with CAH are born with ambiguous external genitalia. Described as tomboys, engage in more male interest play, and are more likely than other women to engage in bisexual and lesbian behavior.

Kidneys

Any excess sodium or water is excreted by the two kidneys in the lower back. Blood enters the kidneys where it is filtered through a complex system made up of more than a million structures known as nephrons. Impurities and excess water and sodium are removed by the nephrons and sent to the bladder for excretion as urine.

Mood, Menstruation, and Childbirth

Approx 5-8 percent of women experience premenstrual syndrome. Women with more severe PMDD experience depression, changes in appetite, and impaired cog performance These symptoms consistent with hypothesis linking serotonin dysfunction with PMDD, leading to the current treatment of medication with selective serotonin reuptake inhibitors (SSRIs) Within one year of baby delivery, approx 10-15 percent of women have postpartum. Mothers at high risk are younger than 20 years of age, unmarried, less educated, and poor. History of abuse, tobacco during last three months of pregnancy also increases risk. Causes of this can be predicted for nearly 90 percent of ppl as early as third trimester of pregnancy by evaluating sensitivity to estrogen signaling.

Typical Age of Puberty

Avg age of puberty went from 16 to 12. Possible explanations for this drop in age at puberty include increased rates of childhood obesity. Accumulation of enough body fat to support reproduction might serve as a signal for puberty Humans who consume meat have experienced some level of exposure to outside sources of sex hormones Phthalates have been found to advance puberty in rats. Also reduces likelihood that boys will play with masculine toys. These are released into air and fluid from plastic and cosmetic products and are found in measurable levels in most of the world's pop. Consumption of soy formula associated with epigenetic change resulting in decreased expression of an estrogen responsive gene. Use of soy formula has been linked to altered age for onset of period and increased risk of uterine fibroids and endometriosis.

Defining Healthy Weight

BMI of 18.5 and 24.9 is healthy, BMI of 25 to 29.9 is overweight, BMI of 30 to 39.9 is obese. BMI of 40 or more is morbidly obese

Intracellular and Extracellular Fluid Compartments

Body has three major compartments for storing water. About two thirds of the body's water is contained within cells as intracellular fluid or cytoplasm (67%). The remaining third is found in extracellular fluid which is further divided into the blood supply (7%) and the interstitial fluid surrounding the body's cells (26%). Cerebrospinal fluid makes up an additional tiny fraction of the percentage of the extracellular fluid Extracellular fluid has higher concentrations of sodium and chloride and intracellular has more potassium.

Pancreatic Hormones

Body's supply of energy from glucose regulated in large part by two hormones, glucagon and insulin. Levels of glucagon increase during periods of fasting, as the body taps into its glycogen stores to maintain blood glucose levels. Insulin helps store glucose as glycogen and helps in moving glucose from the blood supply into body cells. Levels of insulin normally increase after a meal, helping some glucose circulating in the blood supply to move into cells and the rest to be stored as glycogen. Insulin levels are lowest during long periods of fasting. Following a meal, a healthy person experiences a large spike in insulin levels in the circulation. In contrast, a person with type 2 diabetes has a much slower and less dramatic release of insulin. The person with type 2 will not be able to move glucose out of the blood into cells requiring nutrients. The appetite suppressing action of insulin is also less effective for a person with diabetes

desynchronous

Brain activity associated with independent action of many neurons and alertness

synchronous

Brain activity associated with neurons firing in unison and deep sleep

Play Behavior

Children begin to prefer sex-typed toys between ages of 12 and 18 months. At these same ages, children unable to match sex typed toys with male or female faces or voices, suggesting that they haven't yet been socialized to think of toys as "male" or "female". Socialization even less likely to play role in toy choices for monkeys. Young male monkeys spend more time with wheeled toys and balls and females prefer dolls, plush animals, and pots

insomnia

Difficulty in falling asleep or staying asleep

Insomnia

Dreaming about being awake: pseudoinsomnia Medicatiosn for insomnia include benzo and sedatives, zolpidem (Ambien); side effects sleepwalking, binge eating, driving while sleeping

Why Does Drinking Stop?

Drinking slows at least 10 minutes before any real changes in sodium concentrations and cellular hydration occur. This suggests that animals have systems for the "oral metering" of fluid intake. Fluid receptors have been identified in the mouth, throat, and at various levels of the digestive system. Dry mouth doesn't play significant role in initiating drinking but these receptors might be important for deciding when to stop drinking. Rats getting water intravenously consumed water less than normal. This suggests that some of our drinking behavior reflects an "oral need" as opposed to a true need to maintain homeostasis. During extreme endurance activities, low extracellular fluid and low sodium concentration can coexist. During a race an athlete might lose high amounts of sodium and water. As a result, conflicting messages will be sent to the fluid regulation system. The release of ADH can't simultaneously increase (in response to low extracellular fluid levels) and decrease (in response to low sodium concentrations). Because protecting blood volume enjoys a higher priority in terms of survival, the posterior pituitary gland will continue to pump out ADH under these circumstances. Water is retained due to ADH's inhibition of urination, even though this further reduces the concentration of sodium. As extracellular fluid becomes hypotonic, water moves into cell causing strong sense to hypovolemic thirst.

Homeostasis and Motivation

Drive theories of motivation are known as "'push" theories, as the organism is pushed toward a goal to reduce tension and discomfort. Not all motivated behavior works this way. In other cases, organisms are "pulled" toward a goal by the anticipation of rewards or incentives. While it is true we seek food when we fell hungry, the anticipation of feeling pleasure while eating something yummy will also motivate us to eat when we don't need more food.

EEG During Waking

During waking, EEG recordings typically alternate between beta wave and alpha wave patterns. Beta activity is highly desynchronized, rapid (14-30 cycles per second), irregular, low amplitude waves. Alpha waves are slightly slower, larger, and more regular than beta waves, with a frequency of 8 to 13 cycles per second. Improvements in EEG technology gave means to record waking waveforms that are faster than 30 cycles per second, known as gamma band activity. Beta activity is correlated with alert, active, info processing. Closing eyes while awake automatically result in initiation of alpha activity. Alpha and beta activity alternate throughout periods of waking. Alpha is associated with mind wandering and unfocused thought, while beta activity is related to focused thought. Gamma band activity is usually seen in response to stimuli. In kids and young adults, EEG recordings during waking might also include brief moments of theta wave (4 to 7 cycles per second) frequencies, but organized and sustained theta waves during wakefulness is usually restricted to cases of brain damage or neurological disorder. Theta activity characterizes lighter stages of sleep although it begins to intrude into the waking EEGs of sleep deprived volunteers.

Sensation of Thirst

Humans need average of 2.5 liters of water per day. Sensation of dry mouth was the critical stimulus responsible for feelings of thirst, which leads to drinking (Cannon). Hypothesis was wrong. Although the feelings of a dry, dusty mouth and throat stimulate us to take a drink, these feelings are too quickly relieved to be trusted as a means of fluid regulation. Claude Bernard provided more direct evidence against dry mouth theory. Thirst occurs as result of two more sophisticated processes. In first case, osmotic thirst occurs in response to cellular dehydration resulting from drops in the intracellular fluid volume. In second case, hypovolemic (low volume) thirst, occurs in response to drops in blood volume. A combo of these processes contribute to thirst. Osmotic thirst tends to be more common mechanism. Hypovolemic thirst serves as a less frequently used emergency backup system.

Initiation of Eating

Hunger can occur as a function of blood glucose levels. Glucose levels in the blood are high just following a meal. As they drop, a person feels hungry again. Glucose levels tied to insulin levels. Insulin is normally released in response to eating or even to the anticipation of eating. We would expect high levels of insulin and glucose to correspond to satiety and vice versa. Unfortunately there is inconsistency. First, injections of insulin are produce feelings of hunger instead of satiety. Second, patients with poorly controlled diabetes experience substantial hunger in spite of high levels of circulating glucose. So--it is not the total amount of circulating glucose that determines whether we feel hungry but the availability of that glucose to our cells. Another theory of why we feel hungry: "lipstatic theory" suggests that hunger results from low fat supplies.

Regulation of Sex Hormones

Hypothalamus exerts most immediate control over endocrine system. Manages the release of sex hormones through its secretion of gonadotropin-releasing hormone (GnRH). Light sensed by the retina increases GnRH secretion through its action on melatonin. Melatonin normally inhibits the release of GnRH and light in turn inhibits melatonin which is secreted mainly at night. Light increases GnRH release by reducing the inhibition normally produced by melatonin. In nonhuman species, this response of the hypothalamus to light gives a means for producing offspring at the right time of year. Fertility can be timed according to lengthenig or shortening of daylight hours. GnRH secreted by the hypothalamus travels to the anterior pituatary gland. In response to GnRH, the anterior pituitary releases the gonadotropins, LH and FSH. Initial release of these hormones associated with onset of puberty. In males, LH signals the testes to make testosterone. Both testosterone and FSH are required for the maturation of sperm. In females, LH and FSH control the menstrual cycle.

Process of Digestion

If continued fasting depletes stores of glycogen, all body structures except the brain begin to use fatty acids from adipose tissue for energy. Energy can be supplied by ketones, chemicals produced from stored fat by the liver. People with low carb diets often rely on ketones for energy.

Obesity

In 1988, no state in the US reported obesity rates greater than 15 percent. By 2015 no state had an obesity rate less than 20 percent. Sleep deprivation can lead to disturbances in energy metabolism and lead to obesity. Genetics The types of bacteria in a person's gut influence fat storage and obesity. When bacteria from obese mice were transplanted into typical mice, the typical mice increased their body fat 47 percent in two weeks.

Development at Mini-Puberty

In addition to prenatal release of androgens, males experience a second surge of androgen exposure between the ages of one and three months, diminishing by six months. This period is commonly referred to as mini puberty. Most obvious outcome of this exposure is increase in length of baby's penis. Concentrations of testosterone in the urine of male infants predicted their gender typical play behavior at age 14 months. Mini puberty appears to influence later behavioral outcomes.

Cortical Processing of Reward

In response to input from the mesolimbic system and the amygdala, the orbitofrontal cortex (OFC) and ventromedial prefrontal cortex assign positive or negative value to situations. An additional circuit provides attention to significant stimuli and involves the insula, anterior cingulate cortex (ACC) and the amygdala. To avoid making unwanted responses, a final circuit involving the lateral prefrontal cortex and the parietal cortex exerts impulse control. ACC plays important role in cost benefit decisions (ability to delay gratification). Lesions of OFC reverse the rats' normal preference for larger delayed rewards over smaller immediate rewards. Humans with damage to these cortical systems involved in evaluating reward can make remarkably poor decisions, showing little regard for the likely consequences of their behaviors.

EEG During Sleep

In stage 1, EEG is hard to distinguish from waking EEG of a drowsy person. Some theta waves occurs and heart rate and muscle tension begin to decrease. This early stage of sleep is disturbed occasionally by a muscle jerk, referred to as myoclonia. Image of falling on stairs or curb After 10 to 15 min, stage 1 turns into stage 2 NREM which is 50 percent of night's sleep. EEG starts to show sleep spindles, short bursts of 12 to 14 cycle per second waves lasting about half a second that are made by interactions between the thalamus and the cortex. Although spindles prominent in stage 2, they do occur in other stages of NREM. K-complexes also appear. These are single delta waves. Seen in response to unexpected stimuli such as loud noises. Spindles and K complexes might reflect the brain's efforts to keep us asleep while continuing to monitor the external environment After 15 min in stage 2, we enter stage 3 and 4 NREM sleep. During these, body temp, breathing, blood pressure, and heart rate are at very low levels due to the activity of the parasympathetic nervous system. Both stages feature delta wave activity which is the largest, slowest (1-4 cycles per second), most synchronous waveform of the sleeping stage. Stages 3 and 4 differ in that a greater proportion of 4 consists of delta waves. Hard to wake from that stage. After 90 minutes in NREM, a first period of REM sleep occurs. This is referred to a paradoxical sleep reflecting its combo of brain activity resembling waking with the external appearance of deep sleep. Vivid dreaming occurs. The transition between stage 4 and REM is abrupt but involves brief passages through stage 3 and stage 2 sleep. Subsequent periods of REM sleep continue the ultradian cycles observed during waking. In eight hours of sleep, avg person experiences 5 periods of REM. During REM, the EEG shows activity similar to beta activity observed during waking with some periods of theta. Energy use by the brain accelerates, reaching or exceeding rates during wakefulness. The eyes make back and forth movements and this may signify scanning of visual images during dreaming. Sympathetic nervous system becomes active. Heart rate, blood pressure,and breathing become rapid or irregular. First 4 hours of sleep characterized by longer periods of NREM and brief REM. Stages 3 and 4 dominant in first half of sleep cycle. REM is principal stage seen in hours 5 through 8 and any NREM during this time remains in stages 1 and 2. Stages 3 and 4 usually infrequent or absent altogether during the last four hours of sleep. Usually spend last half hour of night's sleep in REM

CC of Eyeblink

Inactivation of the red nucleus by cooling prevents CR.However when the red nucleus recovers, the animals produce strong CR. Learning did occur although performance was suppressed while red nucleus was inactivated Interpositus nucleus primarily responsible for formation of the classically conditioned response of the nictitating membrane in rabbits The degree of age related shrinkage of the cerebellum correlated with the speed of acquisition of conditioned blinking in older adults

Systems Supporting Working Mem

Info being recalled from long term storage is held for relatively brief periods of time in short term. STM has four components: Central executive, phonological loop, visuospatial scratchpad, and an episodic buffer The dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC) are believed to provide the neural basis for the central executive. These areas provide important attentional aspects of STM. Evidence for an executive role for the ACC in STM comes from comparisons of ppl with large or small STM capacities for verbal info. Ppl with large capacities show more activation of the ACC than people with smaller capacities. People with smaller capacities used rehearsal or simple repetition to maintain info in STM whereas people with larger capacities were more likely to use semantic strategies such as imagery or making stories

testis determining factor

a protein encoded by the SRY gene on the Y chromosome that turns the primordial gonads into testes

LTP As a Memory Mechanism

LTP lasts a long time//memories last throughout lifetime It only takes seconds of input to produce LTP LTP does not produce an all or none set of changes in synaptic strength. Instead these changes take place over a series of four stages: generation, stabilization, consolidation, and maintenance.

Biochemistry of Circadian Rhythm

Lesion of SCN abolish the circadian release of melatonin, demonstrating the dependence of the pineal gland on input from the SCN. Melatonin levels are low during the day, begin to rise in the hours before sleep, and usually peak at about 4am, a time when nearly everybody finds it very hard to stay awake. Totally blind ppl experience melatonin peak at different times of day, often leading to sleep difficulties. Melatonin release suppressed by light. Although bright lights more likely to suppress melatonin, dimmer lights typical of indoor lighting and electronics have ability to suppress production and release Cortisol levels normally high early in morning and lower at night. High levels of cortisol related to higher blood pressure, higher heart rate, and mobilization of the body's energy stores. Stress-induced high cortisol levels during the night are correlated with poor sleep quality. Might also contribute to detrimental effects of jet lag. Variations in genes that express melanopsin appear to predispose to seasonal depression. As a result of their melanopsin genes, some people are less sensitive to light in general. The paler light of winter is insufficient for maintaining their normal circadian patterns, leading to circadian disruption and depression. Seasonal depression treated by exposure to bright lights, with or without melatonin supplementation and antidepressants. Light therapy given at dawn corrects cases in which people stay up too late whereas light therapy in the evening helps people who are sleep too early. Following light therapy, serotonin transporter binding in ppl with MDD with seasonal pattern was reduced in a number of brain structures. Serotonin was not cleared from the synapses as quickly following light therapy, allowing released serotonin more chances to interact with postsynaptic receptors. Icelanders experience no more frequent or severe symptoms of depression during winter than during summer. The Icelanders might enjoy protective genetic influences. COmpared to white Canadians living at the same latitudes, whose ancestors immigrated to Canada within past 400 years or less. Icelanders experience lower rates of seasonal depression. Seasonal depression might be more prevalent among those who move from a location with more daylight to one with less, compared to people who experience constant low levels of light for many generations.

Brain Structure and Sexual Orientation

Lesions in INAH-3 in monkeys impairs hetero behavior but does not affect sex drive . INAH-3 two to three times larger in hetero men than in homo. Anterior commissure among structures in humans likely to be sexually dimorphic. Reported that this size varies between homo and hetero men. Unlike hypothalamus, the anterior commissure has no direct role in sexual behavior.

Reward Pathways

Liking is associated with activity in a number of small hedonic hot spots Dopamine is essential to wanting but not for liking.

Brain Mechanisms for Temp Regulation

Lower levels such as spinal cord don't respond to heat or cold until an animal's core temp is as much as two to three degrees away from the set point. Patients with spinal cord injury, which prevents temp regulation of the body by the brainstem and hypothalamus, frequently complain about their inability to manage temp control of their arms and legs. Preoptic area (POA) triggers responses to higher core temps such as panting, sweating, and dilation of blood vessels. The posterior hypothalamus responsible for initiating responses to cooler core temps such as shivering, and blood vessel constriction. The POA has three types of neurons that contribute to the temp set point: warm-sensitive, cold-sensitive, and temp-insensitive. Warm sensitive neurons make about 30 percent of the POA. Creates sweating Cold sensitive neurons make up 5 percent of the POA, but larger numbers found in posterior hypothalamus. Unlike warm sensitive, these don't have any special membrane receptors for sensing coldness in the nearby brain and blood. Instead, these receive inhibitory input from warm sensitive neurons. Reduced activity of warm sensitive neurons results in less inhibition of the cold sensitive neurons, allowing them to increase their activity Temperature insensitive neurons 60 percent of the POA and found in the posterior hypothalamus. Maintain a fairly steady rate of responding under all temp conditions. Gives baseline of activity in the cold-sensitive neurons that is modified by the amount of inhibition provided by the warm-sensitive neurons Pyrogens entering the brain act to gradually increase the body's temp set point, causing fever. The pyrogen's target in the brain is the hypothalamus. The blood-brain barrier is relatively weak near the POA which allows pyrogens to exit the blood supply and enter the brain tissue. Once in the POA, pyrogens stimulate the release of prostaglandin E2, which inhibits the firing rate of warm sensitive neurons Reduced activity in the warm sensitive neurons disinhibits the cold sensitive neurons, increasing their activity, which fools the system into thinking the body is too cold. Activity in the cold sensitive neurons leads to greater production and retention of heat, increased heart rate, shivering, and other symptoms of fever

Cognition

Males have slight advantage in visuospatial tasks and females have slight advantage in verbal and episodic memory or memory for events in a personal timeline. CAH females are mixed results. Testosterone boots spatial performance in both men and women while verbal performance was enhanced by testosterone in men and estrogen in women

Adaptations Maintain Temp

Mammals and birds are endotherms Amphibians, reptiles, and fish are ectotherms The maintenance of body temp is influenced by an animal's surface-to-volume ratio. The larger the overall volume of the body, the more heat is produced by metabolic activity Heat is lost to the surrounding environment as a function of the animal's surface area Smaller animals have more surface area relative to the overall body volume than larger animals do, so small animals must use much more energy to maintain a constant body temp Within a species, populations of animals evolve features that fit a certain environmental niche. In cold climates, surface area and heat loss are reduced in animals that have compact, stocky bodies and short legs, tails and ears To promote heat loss in warm climates, animals have greater surface area in the form of slim bodies and long appendages

Hormones and Sexual Orientation

Men who have older brothers are slightly more likely to be homo than men with no siblings, younger siblings only, or older sisters

Neurochemicals and Hunger

Mice genetically modified to be incapable of producing MCH burned energy faster, ate less, and had less body fat. More likely to die of starvation. Levels of ghrelin are highest during fasting and decrease after a meal. Ghrelin acts as a short term circulating hormone that stimulates hunger, but it also appears to affect feeding by acting on brain circuits involved with memory and reward. Might contribute to the rewarding feeling that is associated with feeding. When leptin levels are high, indicating sufficient fat storage, the orexin cells are inhibited and feeding is reduced. When low, orexin cells are active, orexins are released, and feeding is stimulated. Orexin cells are stimulated by ghrelin which lead to feeding.

Tuner Syndrome

Monosomy: involves sex chromonsomes Sex chromosomes: XO O represents missing sex chromosomes Genotypic females Shorter life expectancy Sterile Learning disabilities Widley spaced napples "webbed" neck

Sleepwaking info

More common in kids; between ages of 4-12 Probably a deep NREM sleep

Klinefelter syndrome info

Most common genetic abnormality. Other symptoms linked to having an extra X chromosome result from interference with the process of X inactivation in which one X chromosome in each female cell is randomly silenced. Left handedness more common. Klinefelter might affect brain lateralization or the localization of specific functions such as language in one hemisphere or the other

REM Networks

Most key REM on areas are located in pons. Rostral pontine reticular formation important because lesions in this area selectively abolish REM sleep. Critical REM off components are the locus coeruleus and raphe nuclei. There is activity in secondary visual cortex. The inactivity of frontal lobe accounts for illogical content of dreams Hippocampus active due to its role in memory consolidation during REM. Amygdala and anterior cingulate cortex active leading to the rapidly changing emotional quality of dreaming

Turner Syndrome info

Most likely maternal X is passed to daughters outnumber cases in which paternal X is passed along by a factor of three to one Show chromosomal mosaicism. Because of this, outcomes among ppl with this can be variable Typical female genitalia but ovaries can develop abnormally into "streak gonad" due to increase in connective tissue. Relatively short, due to absence of one SHOX gene, which regulates long bone development.

Initiation of Drinking

Much research supports the role of the SFO as a target for angiotensin II in the brain. Kadekaro and his colleagues surgically disconnected the SFO from other parts of the brain. Even without normal neural input, neurons in the SFO increased their firing rates when angiotensin II was injected into the blood supply. This result supports the idea that the SFO can respond to circulating angiotensin II alone, without neural input from other areas of the brain. Lesions of SFO interfere with angiotensin induced drinking. Electrical stimulation of the SFO produces immediate drinking behavior. Median preoptic nucleus not in an area where blood brain barrier is weak. Even though it does have receptors for angiotensin II, it can't respond to angiotensin circulating in the blood. It appears that angiotensin II can serve as a classical neurotransmitter within the CNS, passing info between structures like the SFO and median preoptic nucleus Zona incerta sends info to a number of motor regions. Stimulation of the zona incerta produces drinking behavior suggesting that this structure is responsible for initiating the motor components of drinking behavior

Shift Work, Jet lag, and Daylight Saving Time

Night shift workers more likely to get breast cancer. Air flight attendants who crossed time zones at least once a week for four or more years had reduced reaction times and made 9 percent more mistakes on memory tasks than local crews who didn't cross time zones. The crews given insufficient recovery time showed evidence of temporal lobe atrophy People adjust more readily when travel or changes in shift work require staying up later and sleeping later. Easier to adjust to a phase delay of our cycle (setting clock to a later point) than to a phase advance (setting clock to an earlier point). A New Yorker traveling to LA goes to bed three hours later but has the opportunity to sleep later. In contrast a LA person traveling to NY goes to bed three hours early and awakens in what feels like the middle of the night Rates of heart attack increase in the days following the phase advance in spring, but drop following the phase delay in fall

Effects of Healthy Agining on meme

Older brain harder time clearing extracellular adenosine. Adenosine suppresses one of the signaling cascades involved in memory consolidation. Ppl at risk for alzheimers demonstrate increased hippocampal activity during encoding compared to healthy older ppl. This increased activity might give another example of brain's efforts to compensate for decline. eventually this compensation fails as dementia progresses and activity in hippocampus is reduced below healthy ppl

Osmosis Causes Water to Move

Osmosis causes water to move from low to high concentrations of solutes Diffusion is high to low concentration In osmosis, it is the water that moves across a barrier, such as a cell membrane to equalize concentrations of the solutes on either side

Genetics of Sex

Out of the possible combo of three sex chromosomes, females with XXX genotype experience largest reduction in IQ. Significant abnormalities typically arise in cases involving more than three sex chromosomes.

Organizing Role of Sex Chromosome

Outside of the gonads, sex chromosome effects interact with sex hormones in complex ways to produce phenotypes. In rodents, male hormones act to increase body weight, whereas male sex chromosomes decrease body weight. Chromosomes and hormones can create compensatory effects.

Sex chromosome abnormalities

Ppl with Turner and Klinefelter had increased gray matter volume in the parieto-occipital region of the cortex accompanied by decreases in the temporo-insular area.

Memory Reconsolidation

Retrieval stimulates the same memory consolidation processes experienced when the memory was first formed, which can lead to accurate reconsolidation However, reconsolidation incorporates any new info present at the time of retrieval, as if retrieval were a whole new experience

Sleep Restores Our Bodies

Runners competing in ultramarathons add 20-30 minutes of sleep the following night. Most increase in form of NREM. When highly trained athletes skip a day of exercise, they experience substitution of about 15 to 20 minutes of REM sleep for NREM. Small animals which have higher metabolic rates sleep more than larger animals with lower metabolic rates. During NREM sleep lower body temp and rates of metabolism ideal for repairing damage produced by free radicals during wakefulness Release of growth hormone during NREM peaks around onset of puberty and begins to drop at 21. Both growth hormone levels and healing of injuries are reduced by sleep deprivation. Supplementation with GH increases lean muscle mass and bone mass in elderly ppl.

Disorderd eating

Severity ranges from BMI "mild" 17 to 18.4 to severe BMI less than 15 For anorexia, more girls than boys. Men who identify as gay or bisexual have greater risk for eating disorders than men who are straight. Mortality among anorexia is 5%. Binge eating and purging occur on a regular basis typically at least once per week for a period of three months or more. More females than males. Typical binge episode was 1500 cal. Possible that general personality characteristics that produce a vulnerability to eating disorders, not the disorders themselves, are influenced by genetics. Compared to healthy ppl, ppl with anorexia and bulimia show greater connectivity in pathways connecting the frontal lobes and striatum related to reward, but reduced connectivity between the frontal lobes and the hypothalamus. Differences in strengths of these circuits might support the ability of individuals with eating disorders to override homeostatic signals Elevated CART levels have been observed in ppl with anorexia even after patients reached normal weight

Organization During Development

Sex hormones play impt role at three points in early human development: between gestational weeks 6 and 24 (prenatal development), mini puberty, and at puberty Androgen and estrogen receptors are present on both digits 2 and 4, but are more numerous on digit 4. The relationship between prenatal testosterone and estrogen levels determines the relative lengths of the digits. With higher testosterone lower estrogen, the hand develops in the masculine pattern. With higher estrogen and lower testosterone, the hand develops in the female pattern One possible biomarker for the prenatal hormonal environment is the relative length of the digits in the hand. Male 2D:4D ratios particularly in right hand are smaller than female 2D:4D ratios. This means that the female index and ring finger are similar in length while males have more of a difference. Evidence of higher prenatal testosterone predicts better sports performance and more competitive ability. Having low 2D:4D ratio is liked to left handedness, autism, sex-dependent disorders, tomboy Prenatal androgen exposure also effect anogenital distance or the distance between anus and genitalia. This is twice as large in boys than girls. Anogenital distance at birth predicts the extent of later gender related behavior in males but not in females Another potential marker for prenatal hormonal exposure occurs in inner ear. The cochlea of inner ear is able to make it's own sounds, known as otoacoustic emissions. Females produce louder and more frequent emissions.

Romantic Love and Sexual Desire

Sexual desire correlated with activity in back of brain, more involved with short term sensory experience. Romantic love associated with the front, participating in future thinking about more abstract concepts When ppl shown pics of lovers, increased activity was observed in areas of the brain associated with reward. Other areas less active when ppl viewed pics of lover. These areas associated with negative emotions and social judgement. Consequently, love is not only rewarding, but it makes us less judgemental of the person. Vasopressin receptors more expressed in males and oxytocin in females. Vasopressin associated with mobilization and vigilance while oxytocin associated with immobility without fear. Interactions between these help parents achieve balance between care taking and aggression designed to protect their young.

Aplysia californica

Species which was used in experiments that provided initial insights into anatomical synapse changes that occur with learning: sensitization and habituation. Changes during habituation and sensitization: Decreased # synapses during habituation and increased # after sensitization

Systems Supporting Procedural Memory

Striatum, made up of caudate nucleus, putamen, and the nucleus accumbens of basal ganglia involved Basal gang//participation in the learning and memory of actions is logical The nucleus accumbens contributes to evaluation of emotion and reward to the learning of procedures Within striatum, set of interneurons serve as gate for both the learning and performance of procedural mem When reward is available, gate opens allowing the learning and performance of procedures to occur. As a result, the striatum allows organisms to match learning about procedures to their environmental context and likelihood of reward

Sexual Orientation and Cognition

Study using mental rotation tasks for assessing visuospatial skills, men consistently performed better than women, regardless of sexual orientation. Hetero men out performed homo men with bisexual and men scoring between the two groups. Homo and bisexual women scored about equally and both groups outperformed hetero women. Homo men did better than hetero women but both did better than hetero men and homo women who performed at same level

HM

Support for the differentiation of declarative and nondeclarative memories as well as for the stage approach to memory articulated by the info processing model. Damage to medial temporal lobes affects declarative but not nondeclarative memories Monkeys with medial temporal lobe lesions in both hemispheres performed poorly especially as delay period increased. After short delay period monkeys had less difficulty. Like HM they had hard time with LTM. STM are formed and stored in hippocampus then gradually transferred to cerebral cortex at which point the memory traces would then disappear from hippocampus. Later reevaluations of HM showed his remote episodic memories had been more severely impacted than had been previously noted. Hippocampus required for retrieval of episodic memories and that the initial formation of an episodic memory involved involved both hippocampus and cerebral cortex Optogenetics: Early in memory process, prefrontal cortical cells were unable to stimulate freezing behavior during natural memory recall although they could produce freezing when activated by light. Over two weeks, prefrontal cortical cells become necessary for natural recall, while the hippocampal cells become unneccessary. However, the memory trace remained in hippocampus because when stimulated by light, the cells could produce freezing.

Individual Variations in Sleep Patterns

Teen sleep patterns might reflect a dramatic drop in malatonin, one of the neurochemicals involved in the regulation of sleep patterns, at the onset of puberty. Average adult spends only 6 hours and 55 minutes in bed. Our REM cycles appear 90 to 120 minutes during sleep Return to previous sleep pattern in young adults as a reliable indication that brain is fully mature.

Changes in Sleep

The amount of delta waves (stage 3 and 4 NREM) activity is highest between ages 3 and 6.

Body's Internal Clocks Manage Circadian Rhythms

The body's internal master clock is the suprachiasmatic nucleus (SCN) in the hypothalamus. SCN only active in daytime. As light decreases in the evening, accompanied by reduced SCN activity, less input from the sympathetic neurons allow the pineal gland to synthesize and release more melatonin, a neurochemical that modulates brainstem structures related to waking and sleep. The SCN also manages other sleep related changes, including body temp, hormone secretion, production of urine, and blood pressure changes. SCN is master internal clock. When SCN tissue from a short period hamster is transplanted into a normal hamster, the normal hamster shows the short free running cycle. When SCN tissue from a normal hamster is transplanted into a short period hamster, the hamster shows normal 24 hour cycle. Lung and muscle tissue require 6 cycles to adjust to new time and the liver requires 16 cycles. The effects of phase shifts on muscles, lungs, and other tissues appear to last long after the initial discomfort is gone The rhythms of the SCN are heavily influenced by info about light provided by the retinohypothalamic pathway. In contrast, the peripheral clocks are more easily influenced by daily feeding cycles. Abrupt changes in feeding patterns, such as feeding nocturnal mice during the day only, can reset the animals' circadian rhythms by influencing these peripheral clocks. Many travelers attempt to compensate for jet lag by immediately adjusting their mealtimes to their current time zone.

Genes and Sexual Orientation

The chances of a homo male twin having a homo brother are 20 to 25 percent for fraternal twins and 50 percent for identical.

mullerian system

The internal system that develops into a uterus, fallopian tubes, and the upper two thirds of the vagina in the absence of anti-Mullerian hormone

Transcription Factors

Transcription inhibitors prevented long term but not short term memory for classical conditioning in aplysia The transcription factor known as CREB appears to play an active role in long term mem in fruit flies, aplysia, and mammals.

Gender Identity

Transsexuality in biological girls is rare. In contrast, approx 3 percent of women with CAH, raised as girls, express wish to live as men, 600 times greater than general public. 5 percent of girls with CAH express dissatisfaction with female role. Most women with CAH happy with role though. Transsexuality might happen due to prenatal timing of hormone influences on the reproductive systems and on the brain, with influences on the reproductive systems occurring first. If these two processes are separable due to different timing, the two systems might not develop congruently. In a sample of male to female trans, two brain structures known to be sexuallt dimorphic (the central nucleus of the bed nucleus of the stria terminalis (BSTc) and INAH-3) were found to show the typical female pattern of volume. In a female to male case, BSTc and INAH-3 both conformed to the male pattern. Results from exams of both structure volume in adolescents with gender dysphoria or ppl who experience distress due to their sex and gender show that GD youth are much more similar to those sharing their birth sex than with others sharing their preferred gender. However, there are subtle differences in GD youth in sexually dimorphic structures that could create a level of atypical differentiation.

Network Managing Waking

Two pathways originating in reticular formation of the medulla essential to waking. A ventral pathway and dorsal pathway. Locus coeruleus most active when ppl are vigilant and alert but less active when relaxed. Quieter during NREM sleep and totally silent during REM. Anterior raphe nuclei active during wakefulness, less active during NREM, and silent during REM. Brain uses 5 percent more energy when focused than when not focused. Preoptic area (POA) of the hypothalamus referred to as NREM on cells because electrical stimulation of these cells make immediate NREM sleep and lesions result in insomnia. NREM on cells most active during NREM and relatively inactive during waking and REM. Electrical stimulation of thalamus in waking animals produces NREM sleep.

Psychological Disorders

Two thirds of adults with major depressive disorder are female while majority of ppl with autism, attention deficit disorder and tourettes are male.

hypnogogic hallucinations

a REM type dream that intrudes into the waking state prior to the onset of sleep

delta wave

a brain waveform having 1 to 4 cycles per second that occurs during stages 3 and 4 of NREM sleep

theta wave

a brain waveform having 4 to 7 cycles per second found primarily in lighter stages of NREM sleep

k-complex

a brief burst of brain activity consisting of single delta waves occurring during stage 2 NREM sleep

Brain Mechanisms for Satiety

Ventromedial hypothalamus (VMH) Paraventricular nucleus (PVN) Nucleus of the solitary tract (NST) Animals with lesioned VMH seem to establish a much higher set point for food. The NST receives info from glucoreceptors and taste receptors and participates in energy storage. Disruption of this could produce abnormal eating patterns. VMH lesions also result in excess insulin production. Chronically low circulating glucose levels due to excess insulin produce constant hunger and feeding

Responding to Thirst

When either cellular dehydration or hypovolemia is sensed, a sequence of hormone actions helps return fluid levels to their set point Both osmoreceptors and baroreceptors stimulate release of antidiuretic hormone (ADH) also known as vasopressin. ADH two major effects on kidneys. First ADH signals the kidneys to reduce urine production, which conserves fluid. Second, ADH stimulates the kidneys to release the hormone RENIN into the blood supply. Aldosterone signals the kidneys to retain sodium rather than excrete it in the urine. ADH controls the retention of water and aldosterone controls the retention of sodium. Low blood volume stimulates a specific hunger for sodium. Normal sodium levels represent a balance between dietary intake and excretion by the kidneys. If dietary consumption of sodium is high or excretion of sodium by the kidneys is inadequate, high blood pressure and its complications, such as stroke, may occur. High sodium levels in the blood promote the release of water from cells into the circulation due to osmosis. This higher blood volume increases blood pressure. Most medications for high blood pressure are diuretics because promoting urination is an effective way to reduce blood volume. Lower than normal sodium levels are also a risk to health. Vomiting and diarrhea due to illness can reduce sodium and therefore blood volume and blood pressure, to dangerously life threatening levels

Semantic Memory Networks

When naming animals and not tools, medial occipital lobes (visual imagery) lit up. When naming tools, not animals the left premotor area and the left middle temporal gyrus lit up. Anterior temporal lobe serves as hub for semantic cognition.

5 alpha reductase deficiency

a rare condition in which a child is born with ambiguous genitalia but develops male secondary sex characteristics at puberty

baroreceptor

a receptor in the heart and kidneys that measures blood pressure

myoclonia

a muscle jerk occurring in early stages of sleep

alpha-melanocyte-stimulating hormone (alpha-MSH)

a neurochemical originating in the arcuate nucleus believed to inhibit feeding behavior

cocaine- and amphetamine-regulated transcript (CART)

a neurochemical originating in the arcuate nucleus believed to inhibit feeding behavior

sexually dimorphic nucleus of the preoptic area (SDN-POA)

a nucleus in the preoptic area of the hypothalamus that is larger in male rates than in female rats The development of this reflects the early organizing effects of hormone exposure. In humans, more organizing occurs prenatally. In rats, a critical window exists within a few days of birth in which exposure to androgens masculinizes the brain. At birth, the SDN-POA of rats is approx the same size in males and females. Normally the SDN-POA of the male begins to grow rapidly during the newborn period. If a newborn rat is castrated, its SDN-POA is much smaller than normal. If a newborn female is injected with testosterone, its SDN-POA will be much larger than normal. Castration or injection of older animals does not change the size of the SDN-POA indicating that this structure responds to early hormonal organization. Lesions in the area of hypothalamus reduce male sexual behavior.

glucagon

a pancreatic hormone that converts glycogen into glucose

insulin

a pancreatic hormone that facilitates the movement of sugars from the blood supply into the body's tissues

preoptic area (POA)

a part of the hypothalamus involved in a number of regulatory functions, including temp control

lateral hypothalamus (LH)

a part of the hypothalamus that participates in behavioral responses to thirst and in the initiation of feeding behavior

fornix

a pathway carrying information from the hippocampus to the hypothalamus

retinohypothalamic pathway

a pathway leading from the retina of the eye to the hypothalamus; provides light information necessary for the maintenance of circadian rhythms

medial forebrain bundle (MFB)

a pathway that strongly supports ICSS that contains ascending and descending fibers that pass through the lateral hypothalamus to connect to the forebrain and ventral tegmental area

Neuropeptide Y (NPY)

a peptide neurochemical secreted by the arcuate nucleus of the hypothalamus that initiates eating

rapid eye movement (REM) sleep

a period of sleep characterized by desynchronous brain activity, muscle paralysis, eye movement, and storylike dream behavior

melanopsin

a photopigment that is sensitive to ambient light, used by ipRGCs

Adrenocorticotropic hormone (ACTH)

a pituitary hormone that stimulates the adrenal glands

Thyroid Stimulating Hormone (TSH)

a pituitary hormone that stimulates the thyroid gland to release thyroxine, which is necessary for brain development and for growth hormone to have its full impact on body size

paraventricular nucleus (PVN)

a portion of the hypothalamus involved with the regulation of hunger

hypothermia

a potentially fatal core body temp below 31C/ 87.8 F

Karyotype

a profile of chromosome number and appearance in the nucleus of a cell as seen under a light microscope

nicitating membrane

an additional, moveable inner eyelid found in some birds, fish, and mammals but not in humans

5-alpha-dihydrotestosterone

an androgen secreted by the testes that masculinizes the external genitalia

endotherm

an animal that can use internal methods, such as perspiration or shivering, to maintain body temp

ectotherm

an animal that relies on external methods, such as moving into the sun or shade, for maintaining body temp

rhinal cortex

an area of cortex ventral to the hippocampus

subfornical organ (SFO)

an area of the brain located near the junction of the two lateral ventricles that regulates drinking

suprachiasmatic nucleus (SCN)

an area of the brain's hypothalamus that regulates the timing and activity of the sleep-wake cycle (and other biological rhythms)

parahippocampal cortex

an area of the cortex just ventral to the hippocampus

Osmotic thirst

caused by eating salty foods The OVLT is well situated for a role in detecting blood solute levels because the blood brain barrier is weak in this area. OVLT is a probable location for osmoreceptors and also give insight as to how these neurons encode changes in the concentration of their surrounding fluids. OVLT cells from rats were kept alive in an artificial medium resembling interstitial fluid. If the surrounding fluid was made hypertonic, leading to loss of fluid from the cells, the OVLT cells increased their firing rates. When the surrounding fluid was made hypotonic, leading to movement of water into the cells, firing rates decreased.

secondary sex characteristics

characteristics associated with sex but not directly related to reproduction, such as vocal pitch, amount of body hair, breasts, and location of fat deposits

sleep terror

happens during partial arousal from stage 4 sleep, usually begins with a piercing scream

hypertonic

having a relatively higher concentration of solutes than a reference solution

hypotonic

having a relatively lower concentration of solutes than a reference solution

gill withdrawal reflex

in aplysia, a protective reflex in which the gill is retracted in response to touch

unconditioned stimulus (US)

in classical conditioning, a stimulus that unconditionally—naturally and automatically—triggers a response.

conditioned stimulus (CS)

in classical conditioning, an originally irrelevant stimulus that, after association with an unconditioned stimulus (US), comes to trigger a conditioned response.

conditioned response (CR)

in classical conditioning, the learned response to a previously neutral (but now conditioned) stimulus (CS)

nondeclarative memory

memory whose formation does not depend on the hippocampal formation; a collective term for perceptual, stimulus-response, and motor memory accessed unconsciously and automatically

spinal nucleus of the bulbocavernosus (SNB)

motor neurons in the spinal cord that innervate the male rat's bulbocavernosus muscles in the penis

kidney

one of a pair of structures located in the lower back responsible for maintaining fluid balance and for producing urine

intrinsically photosensitive retinal ganglion cells (ipRGCs)

retinal cells that do not process info about visual images, but rather provide suprachiasmatic nucleus

activation

reversible effects of sex hormones on body structures and functions

agouti-related protein (AGRP)

small protein secreted by the arcuate nucleus that initiates eating

otoacoustic emissions

sounds emitted by the cochlea of the inner ear that show sex differences

sleep paralysis

state of being unable to move just after falling asleep or right before waking up

estrogen

steroid hormone that is found in greater quantities in women than men and contributes to female sexual characteristics and development

sexually dimorphic

structurally different in males and females

circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

external genitalia

the external sexual organs, including the penis and scrotum in males and the labia, clitoris, and lower third of the vagina in females

type II diabetes mellitus

the form generally diagnosed in middle aged adults and characterized by resistance to insulin

type I diabetes mellitus

the form of diabetes that appears early in life and is characterized by insufficient production of insulin

sleep debt

the homeostatic control of sleep, in which sleep promotion is related to the preceding duration and intensity of wakefulness

sensory memory

the immediate, initial recording of sensory information in the memory system an initial stage in memory formation in which large amounts of data can be held for very short periods of time

REM rebound

the increased amount of REM sleep following a period of REM deprivation

gender identity

the individual's sense of being male or female

wolffian system

the internal system that develops into seminal vesicles, vas deferens, and the prostate gland in males

osmosis

the movement of water to equalize concentration on two slides of a membrane

organization

the permanent effects of sex hormones on body structures

engram

the physical memory trace for information in the brain

consolidation

the process by which memories become stable in the brain

motivation

the process of activating and directing behavior

translation

the process of synthesizing a protein based on the info carries by a molecule of RNA

long-term memory

the relatively permanent and limitless storehouse of the memory system. Includes knowledge, skills, and experiences.

entrainment

the resetting of internal biological clocks to the 24-hour cycle of the earth's rotation

satiety

the sensation of being full, cessation of eating

obese

the state of being extremely overweight with a body mass index of 30 to 39.9 or a weight that is 20 percent higher than typical

Hypovolemic Thirst

thirst provoked by low blood volume This is sensed by the blood or kidney As blood volume decreases, blood pressure decreases too. When low blood volume is perceived, thirst is initiated, and the kidneys act to conserve remaining fluids

hypovolemic thirst

thirst that results from a decrease in the volume of the extracellular fluid

intracranial self-stimulation (ICSS)

voluntary behavior engaged in by an animal or person that leads to electrical stimulation of a certain part of the brain via a surgically implanted electrode