neuro part 3

addiction, dependence, abuse

Addiction- psychological craving Dependence- looking to experience that substance in order to function normally Abuse- damage that the drug taking has on the person and the community

benzodiazepine

Benzodiazepines facilitate the neurotransmitter effect of: - GABA Changes in Behavior: - relaxation - decreased anxiety and aggression - sleepiness - reduction of muscle tone and coordination Examples: - Diazepam (Valium) - Alprazolam (Xanax)

caffeine

Caffeine blocks receptors for the neurotransmitter adenosine (A) Changes in Behavior: - increased mental awareness - increased energy, decreased fatigue - mild diuretic - increased heart function What % of Americans consume caffeine every day? Around 90 % of Americans consume caffeine every single day in one form or another. Know that caffeine produces both drug dependence and drug addiction. It's important to know that caffeine is an addictive drug. Although, relatively speaking, caffeine's effects on dopamine reward mechanisms are milder. If you feel like you cannot function without it and must consume it every day, then you may be addicted to caffeine.

CB1 and CB2 receptors

CB1 receptors are the most abundant GPCRs in the human brain. CB2 receptors are largely found in immune cells and other peripheral tissues. CB1 receptors are highly expressed in the hippocampus, cortex, basal ganglia, cerebellum and spinal cord. This distribution accounts for the effects of cannabis on memory, cognition and movement. What is the relationship between cannabinoids, body fat and cannabinoid withdrawal syndrome? Cannabinoids are lipid molecules and being highly lipophilic will persist in the body of a user for up to 3 months, while the acute effects last only 4-6 hours. Tolerance develops rapidly. Lack of immediate withdrawal symptoms has led many people to incorrectly conclude that withdrawal does not occur. In actuality, withdrawal is merely delayed due to the extent cannabinoids are sequestered into and slowly released from fat.

endozipines

Endogenous benzodiazepines: Endozepines (peptides produced by glial cells)

how does caffeine stimulate the CNS

It leads to increased neuronal firing, and release of dopamine and glutamate in the CNS. The half-life of caffeine in your body is ~ 6 hours. So if you consume a big cup of coffee with 200 mg of caffeine in it at 3:00 p.m., by 9:00 p.m. ~ 100 mg of that caffeine is still in your system.

homosexual behavior

Know about the studies conducted on homosexual and heterosexual brains that show that the size of INAH-3 in gay men as well as in women is similar. Know that these studies were based upon the brains of homosexual men who had died of AIDS and therefore the brains are unlikely to represent the anatomy or functioning of a brain from a healthy gay man, and that the apparent differences in the INAH-3 cluster are best explained as natural variations in the human population. Understand that while there is good evidence for both genetic and an environmental component, at present Neuroscience only poorly understands the potential genetic or neural basis for homosexual behaviour.

psychomotor stimulants

Know that amphetamine, methamphetamine, caffeine, cocaine, methylphenidate and nicotine are psychomotor stimulants. Stimulants are drugs that increase energy, alertness and activity. A common example is the caffeine present in coffee, tea, chocolate and sodas

sex hormones

Know that sex hormones are steroids and are synthesized from cholesterol

Know that bilateral amygdalectomy in animals can profoundly reduce fear and aggression.

Lesions of the amygdala "flatten" emotion. Bilateral lesions in animals reduce fear and also affect aggression and memory.

narcolepsy

Narcolepsy: sleep/waking disturbance, often characterized by collapse into sleep state (REM-like) triggered by strong emotional expression. Canine narcolepsy: caused by a genetic mutation (hypocretin receptor).

parasympathetic division

pregang neurotransmitter: acetylcholine. postgang neurotransmitter: acetylcholine. "rest and digest" and homeostasis

sympathetic division

pregang neurotransmitter: acetylcholine. postgang neurotransmitter: noradrenaline/norepinephrine "fight or flight"

panic disorder

recurring sudden onsets of intense terror • Predisposed & Overly active Autonomic Nervous System • GABA and Norepinephrine problems • Psychological factor: fear of having a panic attack in public • Women: 2x more likely to have panic attacks

sexual dimorphisms in cognition

they are subtle. females better at verbal tasks, males better at object rotation, map reading, math -Understand that studies conducted in cognitive dimorphism have not yielded any reliable results, and that cognition is related to hormones but no reliable correlations have been discovered.

treatments for anxiety

• Anxiolytic medication: anxiolytic (anxiety-dissolving) drugs act by altering synaptic transmission. Two major classes of anxiolytics are benzodiazepines and serotonin-selective reuptake inhibitors. • Benzodiazepines (e.g. valium = diazepam) bind to a site on the GABAA receptor, increasing its responsiveness to GABA. This increases inhibition in many parts of the brain. Alcohol (ethanol) has anxiolytic effects, through similar mechanisms. • RESULT: GABA mediated inhibition of neuronal excitability Know that GABA receptors are composed of multiple subunits, of which there are many, many subtypes.

ethanol's effects

• Cutaneous vasodilatation: causes a warm feeling but actually increases heat loss, radiate away warmth. • Ethanol increases salivary and gastric secretion. • Ethanol produces a variety of endocrine effects. Eg, increases steriod hormones→ testosterone and estrogen • Inhibits vasopressin (anti-duretic hormone) and oxytocin production from pituitary (posterior) • Chronic male alcoholics are often impotent and show signs of feminization.

schizophrenia and THC

• Describe the similarity between catatonic schizophrenia and the behaviour of animals that have been given Δ9 tetrahydrocannabinol (Δ9-THC). What does this scientific evidence possibly suggest? People with catatonic schizophrenia are frozen physically. Animals that have been given THC also freeze physically in a similar way. This suggests that the same neurotransmitters are being affected.

REM sleep

• • EEG activity resembles waking • • rapid eye movements • • body completely immobilized (muscle paralysis) • • vivid and often illogical episodes of dreaming • • high oxygen consumption by the brain.

location of hypothalamus

wall of third ventricle

phobic disorder

- an irrational, overwhelming, persistent fear of a particular object or situation. Normal fear→ phobia when extreme lengths are taken to avoid it. Social phobia is an intense fear of being humiliated or embarrassed in social situations. • Thalamus, amygdala, and cerebral cortex associated with social phobia. • Learning theorists say that phobias are learned fears. • However, genes appear to play a role in social phobias as well.

cholinergic diffuse modulatory systems

...

human DNA

46 chromosomes: 23 from the mother and 23 from the father X chromosome: ~1000 genes Y chromosome: 10-20 genes

chromosome

A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.

ethanol withdrawal

A well-defined withdrawal syndrome develops in response to ethanol withdrawal. In severe form, it develops after 8 hours The syndrome usually subsides in a few days, but the craving for alcohol and the tendency to relapse last for very much longer. 1st stage symptoms: tremor, nausea, sweating, fever, sometime hallucination. Lasts for ~ 24 hours. May be followed by seizures ('rum fits'). 2nd stage symptoms: 'delerium tremens' develops over the next few days. Patient becomes confused, agitated and often aggressive, and may suffer much more severe hallucinations.

abnormal behavior

Abnormal behavior is a behavior that is: Deviant - a behavior that deviates from what society sees as acceptable. Maladaptive - a behavior that interferes with a person's ability to function effectively in society. Personal distress - an individual feels intense sadness for a prolonged period of time and is unable to find pleasure in activities they previously enjoyed

ADME and drugs

Absorption Distribution Metabolism Excretion

adenosine and sleep

Adenosine is involved in regulating drowsiness via activation of its G-protein coupled receptors. Levels of adenosine in the basal forebrain increase with each hour a person is awake. Adenosine binding also causes blood vessels to dilate, most likely increase oxygen supply during sleep Adenosine reception is important to sleep, especially deep sleep. You may be able to fall asleep, but your body will probably miss out on the benefits of deep sleep. That deficit adds up fast. The next day you feel worse, so you need caffeine as soon as you get out of bed. The cycle continues day after day.

aggression

Aggression is under the control of multiple brain systems and can take many different forms. Example: predatory aggression versus affective aggression. Predatory aggression: attack for the purpose of obtaining food (hunting, "silent kill"). Affective aggression: not aiming to kill or hunt, but to "impress", vocalizations, threatening/defensive postures, high levels of activation of the sympathetic division of the ANS.

androgen levels

Androgen levels mostly testosterone are responsible for masculizing hormonal effects throughout development. They are primarily made by the testes.

hypothalamus as 'master gland'

Anterior lobe of the hypothalamus (gland) produces and secretes hormones that in turn regulate other glands in the body:

anxiety

Anxiety is an emotion that allows an individual to prepare for, or respond to, changes in the environment Briefly describe the following anxiety disorders: generalized anxiety disorder Persistent anxiety for at least 6 months with no clear reason. Worry a lot of the time about minor things. The anxiety usually shifts from one aspect of their life to another. There is a genetic disposition in the neurotransmitter GABA, and respiratory system abnormalities.

bad trip

Bad trip is a slang term for a psychedelic crisis. This is a disturbing experience sometimes associated with use LSD. Manifestations can range from feelings of - vague anxiety - alienation Profoundly disturbing states of - unrelieved terror - ultimate entrapment - cosmic annihilation

barbituates

Barbiturates produce similar intoxication to ethanol. Recreational users report that a barbiturate 'high' gives them feelings of relaxed contentment and euphoria. The main risk of acute barbiturate abuse is respiratory depression. Barbiturates decrease REM sleep, so withdrawal often results in sleep disruptions such as nightmares, insomnia, or vivid dreaming. Examples: phenobarbital, pentobarbital, amobarbital etc.

causes of schizophrenia

Biological Factors Schizophrenia is partially due to genetics. Which chromosome? Structural Brain Abnormalities - enlarged ventricles in the brains of schizophrenics - small frontal cortex and less cortical activity - differences between normal people and schizophrenic brain are small - - many of the changes are prenatal • Propose a possible cause for schizophrenia in terms of a diathesis-stress model. Maternal virus infections Combination of genetic/developmental factors with social/environmental factors schizophrenia becomes manifest in particular individuals. One of the environmental factors now thought to play a significant role is consumption of cannabis. Psychological factors, such as stress, may precipitate acute episodes, but are not the underlying cause. • What evidence suggests dopamine neurotransmission is dysfunctional in schizophrenia? Biological bases of schizophrenia: The dopamine hypothesis: Two lines of evidence: a) amphetamines result in excessive release of dopamine, prolonged and chronic use can lead to psychotic episodes similar to schizophrenia. (Amphetamine increase levels of dopamine in the synapse by blocking reuptake). b) drugs that reduce symptoms of schizophrenia (e.g. neuroleptics such as chlorpromazine) are blockers of dopamine receptors.

superchiasmatic nuclei (SCN)

Biological clocks receive light sensor inputs. Suprachiasmatic nuclei (SCN) in the hypothalamus serve as a biological clock in mammals. Retinohypothalamic tract provides direct input from cells in the retina onto neurons in the SCN. SCN outputs connect to hypothalamus, midbrain. Mechanisms by which brain rhythms are controlled are unclear.

major depressive disorde/ dysthemic disorder

Biological factors include: - genetics - lower prefrontal cortex activity (suggesting a depressed person's brain may not recognize pleasurable opportunities) - decrease in receptors for serotonin and norepinephrine. With depressive disorders the individual suffers depression - especially an unrelenting lack of pleasure in life.

bipolar disorder

Bipolar disorder is characterized by extreme mood swings with at least one or more episodes of mania. The bipolar part of it means the individual experiences both depression and mania. Most individuals with bipolar disorder experience many episodes of depression interspersed with episodes of mania. Genetic influences are stronger predictors of bipolar disorder than depressive disorder. There is also decreased metabolic activity in the cerebral cortex of those with severe major depressive disorder. Some areas of the brain of depressed individuals are underactive, while others are overactive. The amygdala fails to send a signal to the prefrontal cortex about the fear producing memory being gone and so the individual continues to remember the sad event.

caffeine and cocaine

Caffine: Adenosine is an inhibitory neurotransmitter in the CNS. When adenosine binds to the A1 receptor on a neuron, it directly inhibits firing of the neuron. At the molecular level, it activates potassium channels and inhibits calcium channels, which results in a hyperpolarized membrane, which in turn inhibits firing of the neuron. Dopamine release in the basal ganglia increases motor activity; it is antagonized by adenosine, which reduces motor activity. When caffeine binds to the A2A receptors in the basal ganglia it acts in a way similar to dopamine to increase motor activity. This stimulation of motor activity via the basal ganglia, along with adrenaline effects, is how caffeine makes us want to get up and move. Caffeine is an adenosine receptor antagonist, and so has a generally disinhibitory effect on neural activity. It leads to increased neuronal firing, and release of dopamine and glutamate in the CNS. Cocaine: Cocaine inhibits reuptake of the neurotransmitter dopamine

Know that the studies on humans to examine the effect of lesions in the amygdala have reported changes in the patient's ability to recognize emotional facial expressions.

Case of patient S.M. (selective damage to amygdala): deficit in recognizing fear in pictures of people's faces.

circadian rhythms

Coordination of behavior in response to daily cycles of day/night, lightness/darkness etc. Circadian rhythms are controlled by biological clocks.

common features of diffuse modulatory systems

Core formed by a small set of neurons (thousands). Neurons arise from central core of the brain/brain stem. Each neuron has an axon that makes contact with more than 100,000 postsynaptic neurons throughout the brain Synapses allow release of neurotransmitters into extracellular fluid, allowing diffusion to many neurons. Neurotransmitters: NE (norepinephrine = noradrenaline) 5-HT (serotonin) DA (dopamine) ACh (acetylcholine)

cocaine

Cocaine inhibits reuptake of the neurotransmitters: - dopamine (DA) - serotonin (5HT; 5-hydroxytryptamine) - norepinephrine (NE) Changes in Behavior: - increases mental awareness, - feelings of well-being and euphoria - hallucinations - delusions of paranoia or grandiosity - increases motor activity - tremors/convulsions followed by respiratory depression

HPA axis

Components of the stress response: avoidance behavior, increased vigilance and arousal, activation of sympathetic ANS, release of cortisol (mediated by the hypothalamic-pituitary-adrenal (HPA) axis) Parvocellular neurosecretory neurons in the hypothalamus → release of corticotropin-releasing hormone (CRH) → adrenocorticotropic hormone (ACTH) → cortisol amygdala and hippocampus. Activation of the hippocampus suppresses the HPA axis. Glucocorticoid receptors in the hippocampus respond to cortisol and the hippocampus suppresses CRH release from the hypothalamus. Amygdala and hippocampus have opposite effects on the stress response. Over-activation of the amygdala or under-activation of the hippocampus can lead to an excessive activation of the HPA system.

DNA

Deoxyribonucleic acid is a nucleic acid containing the genetic instructions used in the development and functioning of all known living organisms (with the exception of RNA viruses). The DNA segments carrying this genetic information are called genes.

how ethanol acts

Despite the long history of ethanol use and decades of research into its effects, the mechanism of action remains among the least understood of nearly all psychoactive drugs. Pinpointing a site of action or single mechanism of alcohol effects is difficult because the drug affects virtually all neurochemical and endocrine systems. Describe three main theories that account for the effects of ethanol in the brain. - enhancement of GABA-mediated inhibition (similar to the actions of benzodiazepines). - inhibition of Ca2+ entry through voltage-gated Ca2+ channels. - inhibition of NMDA receptor function. - inhibition of adenosine transport.

activity of diffuse modulatory systems in sleep/wakefulness

Diffuse neuromodulatory systems are critical for controlling waking and sleep. Wakefulness and awakening: • Lesions of the brain stem can cause sleep and coma ("ascending reticular activating system"). • Cells in the locus coeruleus (norepinephrine) and raphe nucleus (serotonin) increase their activity in anticipation of awakening, increasing excitability of cortical neurons and suppressing brain rhythms. Falling asleep and the non-REM state: • Decrease in firing of many brain stem neurons, increased firing in some cholinergic neurons.

human brain sexual dimorphisms

Dimorphisms are difficult to asses. Small, variable from one individual to the next, measurement techniques are not very sensitive, location may not be obvious collection of matching sample is extremely difficult. Spinal cord: Onuf's nuclei (alpha motor neurons) in the sacral spinal cord. Innervate the bulbocavernous muscle. In the male is responsible for penile erection and in the female contraction of vaginal muscles. The nuclei is larger in the male since they innervate a larger muscle. Brain: preoptic area of the anterior hypothalamus. Role in reproductive behaviours. Sexually dimorphic nuclei (SDN). 5-8 times larger in the male than in the female. RATS (See next slide) Brain: 4 clusters of neurons called interstitial nuclei of the anterior hypothalamus (INAH). INAH-1 seems to be equivalent to the SDN (not dimorphic). INAH-2 and INAH-3 are larger in men than women 2-3 times). Indirect involvement in sexual activity. These neurons fire more during copulation in male rhesus monkeys -human brain dimorphism outside the hypothalamus has been difficult to prove.

dopaminergic diffuse modulatory systems

Dopaminergic neurons are located in the substantia nigra and the ventral tegmental area. Substantia nigra neurons innervate striatum (part of basal ganglia) and facilitate the initiation of voluntary movements. Their degeneration/death causes Parkinson's disease. Ventral tegmental area neurons innervate frontal cortex. These projections are involved in reinforcing reward-related behaviours.

zeitgeibers

Environmental time cues (light/dark or temperature) act as time markers ("zeitgebers"). Explain how zeitgeber deprivation influences circadian rhythms. Animals exposed to these signals maintain a 24-hour rhythm. without them -zDeprived of time markers, rhythms often continue with a period that is slightly longer than 24 hours. Rhythms "run free". Humans initially settle into a roughly 25-hour rhythm (longer periods possible). (a) What happens when the rhythms of temperature and sleeping-waking become desynchronized? (b) Give some examples of zeitgebers. light/dark, temperature

EEG

First recorded by Hans Berger in 1929. EEG recordings are noninvasive, painless, do not interfere much with a human subject's ability to move or perceive stimuli, are relatively low-cost. -The electroencephalogram measures the activity of large numbers (populations) of neurons -Electrodes measure voltage-differences at the scalp in the microvolt (μV) range. Voltage-traces are recorded with millisecond resolution - great advantage over brain imaging (fMRI or PET). -EEG electrodes measure current flow due to synaptic activity on dendrites of pyramidal neurons. -Many neurons need to sum their activity in order to be detected by EEG electrodes. The timing of their activity is crucial. Synchronized neural activity produces larger signals.

frontal lobotomy

Frontal lobotomy: Removal/disconnection of a large portion of the front lobe to relieve anxiety and aggression. 50,000 lobotomies performed in the U.S. (mostly 1940's and 50's). Egaz Moniz wins Nobel Prize in 1949. "Side effects" of lobotomy: • No loss of IQ or memory, but • blunting of emotional response • loss of the emotional components of thoughts • inappropriate behaviour • lowered moral standards • lack of concentration.

gender

Gender: is medically defined as the many biological characteristic, and qualities that distinguish males from females. Including the nature of the sex chromosomes, and the anatomy of the gonads and other sex organs.

hallucinogenic drugs

Give some examples of hallucinogenic drugs. Lds, mescaline, Psilocybin / Bufotenin (dimethyl serotonin) How do hallucinogens affect the CNS? Give an example of a behavioural change produces by hallucinogens. What is Hallcucinogen Persisting Perception Disorder? Users of LSD are susceptible to having flashbacks and Hallucinogen Persisting Perception Disorder (HPPD)

inhalants

How do you think people obtain inhalants compared to other drugs? Based on this answer, what sort of people are more likely to abuse inhalants? Abuse of hundreds of chemicals; can be aerosols, gases, nitrites, volatile solvents Probably teenagers cause they're derp derp derp or people who like the smell of sharpies (mmm)

amphetamine

How does amphetamine/methamphetamine stimulate the CNS? Amphetamine increases the release of, and inhibits reuptake of the neurotransmitters: - dopamine (DA) - norepinephrine (NE) Give an example of a behavioural change amphetamine/methamphetamine produces. Changes in Behavior: - increased mental alertness - increased energy How is amphetamine absorbed in different ways and why?

mullerian/wolffian ducts

Identify the two structures in the uncommitted gonad as the Müllerian and Wolffian ducts. Understand that the Wolffian duct develops into the male reproductive system, if the fetus has a Y chromosome and a SRY gene. Know that under this condition, the Müllerian duct is prevented from developing. In addition, explain what happens to the Wolffian duct if the fetus does not have a Y chromosome).

PCP ketamine /date rape drugs

Impair memory, intoxication, thought disorder

alcohol and dementia

In addition to the acute effects on the nervous system, chronic administration also cause irreversible neurological effects. This may be due to ethanol itself, or to metabolites such as acetaldehyde or fatty acid esters. The majority of heavy drinkers develop irreversible dementia and motor impairment associated with thinning of the cerebral cortex. Degeneration also possible in cerebellum and other specific brain areas, as well as peripheral neuropathy. Some of these changes are due to thiamine deficiency, which is common in alcoholics.

amygdalectomy

Involvement of amygdala in social hierarchy: Pribram's experiments documented disruptions of social hierarchies (dominance relationships) after amygdala lesions.

bed nucleus of the stria terminalis

Long-term, generalized emotional arousal depends on a brain area called the bed nucleus of the stria terminalis.

monoamine hypothesis of mood disorders

Monoamines are neurotransmitters like serotonin, norepinephrine, and dopamine in the synaptic cleft between neurons. This hypothesis suggests that mood disorders are caused by low levels of these neurotransmitters. Most drugs that are used to treat these disorders increase their levels. An example of these drugs is an SSRI, which blocks the reuptake of serotonin and increases serotonin levels.

role of amygdala in fear and aggression

Main subdivisions of the amygdala: corticomedial nuclei (black clusters in the purple area), basolateral nuclei (brown clusters in the red area).The amygdala receives inputs from all major sensory systems (visual, auditory, somatosensory, etc.). Connects to the hypothalamus. Electrical stimulation of the amygdala: increased vigilance and attention, increased anxiety and fear. Many memories have emotional content. Amygdala neurons can learn to respond to painful stimuli and then evoke a fearful response. Fear conditioning: increased heart rate elicited by a tone associated with pain (learned fear). -Know that memories associated with fear can be formed quickly and can last longer.

single emotion system in the brain?

Many structures in the brain are multi-functional (for example sensory/motor/emotional). Emotions are highly diverse. -many brain areas can respond to different emotions

marijuana

Marijuana stimulates neurotransmitter receptors for: - endocannabinoids (eCBs) This causes an increase in negative feedback of both excitatory and inhibitory neurotransmitter systems. Changes in Behavior: - relaxation, mild euphoria - introspection and metacognition - decrease pain and nausea - sensory distortions, especially of time - impairs memory - stimulates appetite/feeding - anxiety and paranoia

methadone

Methadone is ~ equal in potency to morphine, but induces less euphoria and has a somewhat longer duration of action at μ receptors. Methadone causes a withdrawal syndrome that is milder but more protracted (days to weeks). Allows controlled withdrawal of dependent abusers of heroin and morphine. Patient is then slowly weaned off methadone

MDMA

Methylenedioxymethamphetamine (MDMA; Ecstasy) stimulates neurons to release: - dopamine (DA) - serotonin (5-HT) Changes in Behavior: - low doses increases arousal (like amphetamine) - high doses cause hallucinations (like LSD) - sense of well being and social interactivity - feelings of empathy - increased feelings of intimacy with others - euphoria - decreased hostility and insecurity What are the effects of an MDMA overdose? Ecstasy overdose: - usually presents with a very high body temperature and blood pressure, hallucinations and an increased heartbeat - known to cause death by: bleeding in the brain; renal failure; dehydration; excessive blood pressure

mood disorders

Mood disorders occur where there is a primary disturbance of mood. It can include: - cognitive - behavioral - somatic symptoms - interpersonal difficulties.

narcotics/opiods

Narcotics are drugs that produce drowsiness, insensitivity to pain, and decreased responsiveness. Opioids such as morphine, heroin and codeine are common examples How do opioids affect the CNS? Give an example of a behavioural change produces by an opioid drug. Morphine and Heroin stimulate neurotransmitters for: - endorphins (act on μ, δ and κ opioid receptors) Changes in Behavior: - decrease pain - euphoria - feel warm, happy, content - withdraw from the world. Horrific withdrawal effects. Once the drug leaves the brain, the affected synapses are less responsive - this leads to anxiety, pain and exaggerated responses. Opioid (especially Heroin) withdrawal symptoms are some of the nastiest an addict can experience. Withdrawal occurs with an abrupt discontinuation of use or even a decrease in their daily amount of opioid taken. The onset of opioid withdrawal symptoms begin 6 to 8 hours after the last dose is administrated. Major heroin withdrawal symptoms peak between 2 and 3 days after the last dose of heroin and subdue after about 1 week. -vomitting, panic, etc

diffuse modulatory systems

Neurotransmitter systems are systems of neurons in the brain expressing certain types of neurotransmitters, and thus form distinct systems. Activation of the system causes effects in large volumes of the brain, called volume transmission. The major neurotransmitter systems are the noradrenaline (norepinephrine) system, the dopamine system, the serotonin system and the cholinergic system. Drugs targeting the neurotransmitter of such systems affects the whole system, and explains the mode of action of many drugs. Most other neurotransmitters, on the other hand, e.g. glutamate, GABA and glycine, are used very generally throughout the central nervous system. -mostly g-protein coupled, affects behaviors

nicotine

Nicotine activates receptors that normally recognize: - acetylcholine (ACh) Give an example of a behavioural change nicotine produces. - increased arousal, relaxation - increased arousal - mild degree of euphoria - improved attention, learning, problem solving - increased reaction times - appetite suppressant How is nicotine differentially absorbed by the mouth, lungs and nasopharynx of cigarette, pipe and cigar smokers? -pipe and cigar is less acidic, can be absorbed through mouth How long is the withdrawal syndrome for nicotine? Withdrawal lasts 2-3 weeks, although the craving for cigarettes persists for very much longer than this.

noradrenergic diffuse modulatory system

Noradrenergic neurons are located in the locus coeruleus. Widely branching axons reach cortex, thalamus, hypothalamus, cerebellum, etc. Involved in regulation of attention, arousal, sleep-wake cycles, learning and memory, anxiety, pain, mood, and brain metabolism. Effective stimuli activating noradrenergic neurons: novel and unexpected stimuli in the environment.

functions of brain rhythms

One idea: Synchronized rhythmic activity serves to "disconnect" the brain from acute inputs during sleep. Another idea: Synchronized activity serves to coordinate neurons in different parts of the brain (remember perceptual grouping - see unit 2). Or perhaps: Rhythms have no function, but are just by-products of an inherent tendency of brain circuits to engage in rhythmic activity.

Which two neurohormones are secreted by the hypothalamus onto the capillary bed of the posterior pituitary lobe?

Oxytocin: contractions of the uterus, milk ejection from mammary glands. Vasopressin (antidiuretic hormone; ADH): regulates blood volume and salinity.

types of schizophrenia

Paranoid schizophrenia - delusions organized around a grand theme - often accompanied by auditory hallucinations - some chance of rehabilitation As a rule, people with this form are more cognitively Intact. They generally take care of themselves well enough to get through the activities of the day. Some manage to complete college work and take good jobs. Disorganized schizophrenia - lack of emotional expression - disorganized behaviour - incoherent speech - worsening time course, no remission Interviewer: "How does it feel to have your problems?" Patient: "Who can tell me the name of my song? I don't know, but it won't be long. It is won't be short, tall, none at all. My head hurts, my knees hurt - my nephew, his uncle, my aunt. My God, I'm happy... not a care in the world. My hair's been curled, the flag's unfurled. This is my country, land that I love, this is my country land, that I love. Catatonic schizophrenia - immobility and stupor - bizarre posturing and grimacing Periods of extremely rapid, repetitive activity alternate with periods of total inactivity. During the inactive periods, the person may hold a rigid posture and resist attempts to alter it.

periventricular zone of hypothalamus

Periventricular zone: suprachiasmatic nucleus (circadian rhythms), cells regulating the autonomic nervous system (ANS) neurosecretory neurons. Axons of neurosecretory neurons extend downward into the stalk of the pituitary gland. Two lobes: anterior (gland) and posterior (brain region). Magnocellular neurosecretory cells release substances (neurohormones) into capillaries in the posterior lobe of the pituitary gland.

evidence of limbic system involved in emotion

Phineas Gage injured on September 13, 1848 by a tamping iron. Damaged to limbic system changed emotions/personality.

types of conditioning experienced by addict

Physical dependence is not the major factor in sustaining long-term drug dependence, psychological reinforcement is more important Positive reinforcement - the pleasure felt from the 'reward pathway' being stimulated. Negative reinforcement - the aversion to drug cessation (withdrawal symptoms) that subjects attempt to escape by self-administering the drug. Conditioning also plays a significant role in sustaining drug dependence. Virtually all dependence-producing drugs activate the 'reward pathway' - the mesolimbic dopamine pathway - even though their primary sites of action are generally elsewhere. The reward pathway mediates our feelings of motivation, reward and behaviour.

serotonin and HPA axis in mood disorders

Professionals believe people with mood disorders may have depleted levels of serotonin. SSRI drugs block the reuptake of serotonin which increases the amount in the brain. These usually help with the disorders. Biological bases of mood disorders: Some drug side effect sparked the monoamine hypothesis of mood disorders (mood is associated with the levels of monoamine modulatory neurotransmitters, i.e. norepinephrine and serotonin). But modulators do not "equal" mood. Causes: 1) Too little Serotonin. Idea strengthened by the fact that drugs that elevate serotonin relieve depression (70% of patients). Other than victims of violent suicide, scientists "have not been able to determine that depressed people have a deficiency".

cortisol

Regulation of the adrenal glands: Release of corticotropin-releasing hormone (CRH) by periventricular hypothalamic neurons in response to stress. CRH stimulates the release of adrenocorticotropic hormone (ACTH) into the bloodstream. ACTH triggers release of cortisol (steroid hormone) from adrenal glands (adrenal cortex). Cortisol binds to neurons throughout the CNS. Cortisol causes increased Ca2+ influx. Too much calcium can cause cell death. Chronic stress causes cell death and premature aging of the brain. Posttraumatic stress disorder is associated with neurodegenerative changes in parts of the brain.

EEG frequencies

Rhythms occur in distinct frequency ranges: Gamma: 20-60 Hz ("cognitive" frequency band) Beta: 14-20 Hz (activated cortex) Alpha: 8-13 Hz (quiet waking) Theta: 4-7 Hz (sleep stages) Delta: less than 4 Hz (sleep stages, especially "deep sleep") Higher frequencies: active processing, relatively de-synchronized activity (alert wakefulness, dream sleep). Lower frequencies: strongly synchronized activity (nondreaming sleep, coma).

methylphenidate

Ritalin inhibits reuptake of the neurotransmitters: - dopamine (DA) Changes in Behavior: - increases mental awareness, - milder effects than cocaine; no rush. Ritalin is a strong, but slow acting stimulant. Know that methylphenidate is prescribed as a treatment for ADHD and narcolepsy under the brand name, Ritalin. Why is methylphenidate generally less disruptive to behaviour than cocaine is despite the drugs' similar mechanisms? The effects of a methylphenidate pill develop and decline in the brain much more slowly than do those of cocaine.

rats vs humans sexual dimorphisms

Rodent male and female hypothalamus show obvious differences. Differences in the somatosensory cortex. Avian species show singing related song nuclei mostly in the males. Humans subtle differences.

meth binge abuse cycle

Rush (5-30 mins) - heartbeat races and metabolism, blood pressure and pulse soar; feelings of pleasure High (4-16 hours) - feel aggressively smarter and become argumentative Binge (3-15 days) - maintain high for as long as possible; become hyperactive, both mentally and physically. Tweaking - the most dangerous stage of the cycle for the addict. No sleep for 3-15 days, become irritable and paranoid. Tweakers can appear normal. But a closer look will reveal their eyes are moving 10x faster than normal, the voice has a slight quiver, movements are quick and jerky. Withdrawal (30-90 days) - no immediate symptoms are evident to begin with But the user will become depressed and then lethargic. The craving for meth hits and they may become suicidal. Other symptoms include: fatigue/excessive sleeping, agitation, and psychosis.

SRY

SRY gene encodes for the testis determining factor or TDF protein

symptoms of schizophrenia

Schizophrenia is characterized by highly disordered thought processes. Some of the symptoms of schizophrenia are: - disordered thought - odd communication - inappropriate emotion - abnormal motor behavior - social withdrawal. Positive symptoms: something is being added that results in distortion or an excess of normal behavior. Eg: hallucinations Negative symptoms: loss or decrease of normal behavior. Example: An individual with a flat affect shows little or no emotion, and maintains an immobile facial expression.

epilepsy

Seizures: pathological states of synchronized brain activity. Often indicative of brain injury or pathology. Some drugs act as convulsants (triggering brain seizures). Epilepsy: repeated and recurrent experience of seizures -• Understand that seizures are an extreme form of synchronous activity.

serotonergic diffuse modulatory systems

Serotonergic neurons are located in the raphe nuclei. Neurons innervate the spinal cord, as well as the brain itself. Activated during wakefulness, suppressed during sleep. Involved in control of sleep-wake cycles and sleep stages, as well as mood and emotional behaviour.

serotonin and aggression

Serotonin and aggression: Serotonergic neurons project to the hypothalamus and are thought to be involved in regulating hypothalamic function. Isolation-induced aggression (reduced turnover of serotonin) Influence of serotonin agonists/antagonists on dominance hierarchies: Drugs blocking the synthesis or release of serotonin (including serotonin antagonists) increase aggressive behaviour. But, an animal with higher serotonin levels may become socially dominant. Conversely, animals injected with serotonin antagonists become more subordinate in the hierarchy (despite higher incidence of aggression). In this case aggression does not determine social dominance

serotonin and anxiety

Serotonin-selective reuptake inhibitors (SSRIs, e.g. prozac = fluoxetine, and zoloft = sertraline) prolong the actions of serotonin by inhibiting their reuptake back into the presynaptic terminal after release, e.g. from terminals of serotonergic neurons of the diffuse modulatory system. Therapeutic effects of SSRIs are due to a slow adaptation of the brain to elevated serotonin levels, including an increase of glucocorticoid receptors in the hippocampus. Increase of serotonin levels in the brain: 1)Increased doses of L-tryptophan will proportionally increase -hydroxytryptamine (5-HT or serotonin). 2)Amphetamines or other drugs increase released of stored serotonin. 3)Inhibition of serotonin metabolisms by monoaminooxidase (MAO) inhibitors will increase presynaptic neuron by uptake blockers. 4)Impairment of 5-HT transport into the presynaptic neuron by uptake blockers. (e.g. selective serotonin reuptake inhibitors or tricyclic antidepressants), increases synaptic 5-HT concentrations. 5)Direct serotonin agonists can stimulate postsynaptic 5-HT receptors. 6)Lithium increases postsynaptic receptor responses.

example of male and female hormones

Sex hormones are steroids: derived from cholesterol. Androgens (male) and estrogens (female). Made primarily by the gonads. Both sexes have "male" and "female" hormones. Aromatase converts testosterone a "male" hormone into estradiol a "female" hormone. TDF induces its synthesis.

sleep apnea

Sleep apnea (or sleep apnoea in British English; English pronunciation: /æpˈniːə/) is a sleep disorder characterized by abnormal pauses in breathing or instances of abnormally low breathing, during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour.[1] Similarly, each abnormally low breathing event is called a hypopnea. Sleep apnea is diagnosed with an overnight sleep test called a polysomnogram, or "sleep study".

methanol and ethylene glycol

Some alcoholics drink methenold bc they have a high tolerence Methanol is converted to formaldehyde Drinking methanol can lead to blindness Medical use of ethanol- can be used as treatment if someone drinks other 2 chems. Competes at binding sites with others Ethylene glycol- tastes sweet, young kids and pets are susceptible bc of taste

long-term effects of stress

Stress leads to the release of cortisol. Cortisol binds to cortisol receptors in neurons, which then travel to the neuron's cell nucleus and affect gene transcription and protein synthesis. Cortisol causes increased Ca2+ influx. Too much calcium can cause cell death. Chronic stress causes cell death and premature aging of the brain. Posttraumatic stress disorder is associated with neurodegenerative changes in parts of the brain.Stress can kill!

TDF

TDF is a transcription factor. Target genes controlled by TDF: aromatase and Mullerian inhibiting- factor. A person with the Y chromosome and TDF develops as a male.

cannon-bard theory

The Cannon-Bard theory: emotional experience can occur in the absence of emotional expression.

james lange theory

The James-Lange theory: we experience emotion in response to physiological changes in our body ("we feel sad because we cry, "angry because we strike, afraid because we tremble"). (find revised)

PCP and schizophrenia

The glutamate hypothesis: PCP produces many of the symptoms of schizophrenia, but acts on the glutamate system. It is an NMDA channel blocker.

the limbic system

The Papez circuit (1930s): cortex involved in emotional experience, hypothalamus involved in emotional expression. Structures together form the limbic system. The Fifth Lobe? The limbic lobe according to Paul Broca (1878).

autonomic nervous system

The autonomic nervous system (ANS or visceral nervous system or involuntary nervous system) is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions.[1] The ANS affects heart rate, digestion, respiratory rate, salivation, perspiration, diameter of the pupils, micturition (urination), and sexual arousal. Whereas most of its actions are involuntary, some, such as breathing, work in tandem with the conscious mind.

where pregang axons emerge from the spinal chord

The autonomic nervous system consists of a sympathetic and a parasympathetic division. Preganglionic axons of the sympathetic division emerge from the middle third of the spinal cord (thoracic and lumbar segments). They synapse onto neurons in the ganglia of the sympathetic chain or in collateral ganglia. Preganglionic axons of the parasympathetic division emerge from the brain stem and the sacral segments of the spinal cord. They travel to parasympathetic ganglia next to or within their target organs. ANS innervates: glands smooth muscle cardiac muscle

theories to disorders

The biological approach refers to disorder causes that are organic and internal. Drug therapy is often used to treat the disorder. The medical model describes psychological disorders as medical diseases with a biological origin. psychological approach emphasizes the contributions of: - experiences - thoughts - emotions - personality characteristics Behavioral psychologists - rewards and punishments in the environment determine the abnormal behavior. Social cognitive psychologists - observational learning, cognitions, and beliefs as factors that foster abnormal behavior.

ethanol and adenosine

The depressant effect of ethanol resemble those of adenosine on A1-receptors. Ethanol in cell culture has been shown to increase extracellular adenosine by inhibiting adenosine uptake. That, and other evidence, suggest that inhibition of the adenosine transporter may account for some of its CNS effects.

diathesis stress model

The diathesis-stress hypothesis (diathesis = predisposition): Genetic and environmental factors affect the HPA axis (see anxiety disorders), HPA axis is hyperactive in most depressed patients (elevated levels of blood cortisol), also decreased levels of glucocorticoid receptors in the hippocampus (less feedback regulation). These receptors are regulated by genes and environment/experience. This may explain the increased risk for developing mood or anxiety disorders after childhood abuse and neglect.

the parts of the hypothalamus that mediate affective and predatory aggression.

The lateral hypothalamus projects to the ventral tegmental area (VTA) via the medial forebrain bundle. Stimulation of the VTA can elicit behaviours resembling predatory aggression. Cutting the medial forebrain bundle eliminates predatory aggression following stimulation of the lateral hypothalamus. The medial hypothalamus projects to the periaqueductal gray matter via the dorsal longitudinal fasciculus. Stimulation of the periaqueductal gray matter can elicit affective aggression, lesions can disrupt the behaviour.

familial homosexuality

The probability of a man to be homosexual is higher if other males in the family are homosexuals. Incidence associated to the cousins and uncles related through a man's mother rather than the father. X-linked? Analyzed the x-chromosome of 40 homosexual brothers (not twins). Through genetic recombination, a particular segment of DNA is the same in two brothers only about 50% of the time. In gay brothers, the chance of the tip of chromosome X to be the same was higher. In contrast: Fewer than 100% of identical twin share sexual orientation.

seizure activity in the reticular formation

The reticular formation is a network of cells and fibers threaded throughout the hindbrain and midbrain that alters the activity of the rest of the brain. complex seizures involve the whole brain, including the reticular system, thus producing abnormal electrical activity throughout both hemispheres.

different approaches

The sociocultural approach places more emphasis on larger social contexts in which a person lives. Marital conflict or ineffective family functioning may be the cause of psychological disorders in families. The living conditions of those individuals living in poverty can create a stressful situation that can contribute to the development of a psychological disorder. biopsychosocial approach, none of the previous factors is considered more important than another. They are all considered important factors in normal and abnormal behaviors. These various factors in multitudes of combinations create expressions of abnormal behavior that are unique to individuals, which accounts for the differences we might see in two people who have been diagnosed with the same disorder (i.e. depression).

somatic nervous system

The somatic nervous system (SoNS or voluntary nervous system) is the part of the peripheral nervous system [1] associated with the voluntary control of body movements via skeletal muscles. The SoNS consists of efferent nerves responsible for stimulating muscle contraction, including all the non sensory neurons connected with skeletal muscles and skin.

function of sleep

Theories of restoration: Sleeping is for resting and recovery. • Quiet rest is not a substitute for sleep (the brain needs to be asleep). • But what exactly is restored? Theories of adaptation: Sleeping is for keeping out of trouble. Adaptation for keeping away from predators, or for conserving energy.

three zones of hypothalamus

Three zones of the hypothalamus: lateral, medial, periventricular. Lateral and medial zones regulate behaviors such as feeding, etc.

controlled substances act

Tobacco, beer, wine, and spirits are explicitly exempt from the Controlled Substances Act, as is caffeine. What criteria are required to classify a drug as Schedule I? Schedule I drugs are those where: A. the drug or other substance has high potential for abuse. B. the drug or other substance has no currently accepted medical use in treatment in the United States. C. there is a lack of accepted safety for use of the drug or other substance under medical supervision. Examples of Schedule I drugs: - γ-hydroxybutyric acid (GHB) - Cannabis - Heroin - MDMA (Ecstasy) - Psilocybin - LSD - Peyote/Mescaline (a narrow exception to its illegal status for religious use by members of the Native American Church)

treatments for mood disorders

Treatments for mood disorders: More than 80% of patients improve when they receive appropriate treatment. Electroconvulsive therapy (mechanism unknown, memory loss side effects). Psychotherapy (increased cognitive control?) Antidepressants (e.g. tricyclics, SSRI's (fluoxetine), MAO inhibitors, clinical effectiveness after adaptive brain response) Lithium (monovalent cation, effects include inhibition of adenylyl cyclase)

functional brain states

Two major functional brain states: • Waking • Sleep non-REM sleep: •slow-wave sleep high amplitude-low frequency EEG activity •no dreaming •reduced muscle tension •occasional movements (incl. rare eye movements) •low rate of energy use •low heart rate and respiration ("an idling brain in a moveable body").

prairie vole vs montane vole

Understand how oxytocin and vasopressin are released into the CNS, and that they bind to specific receptors scattered around the brain. Know that the maps of these receptors are very different in the two types of voles, although maps of other neurotransmitter and hormone receptors are similar. Know that the maps in the two species resemble each other when female meadow vole gives birth.

sexual responses

Understand that the neural control of the sexual response is initiated, in part, from the cerebral cortex, but the spinal cord mediates the sexual responses of genitals.

ethanol (alcohol)

What are the effects of ethanol on neurotransmitter receptors?Describe the behavioural change ethanol produces? Ethanol enhances the neurotransmitter effect of: - GABA Changes in Behavior: - relaxation - decreased inhibitions - impaired memory and judgment - diuretic Intoxication produces: - slurred speech. - motor incoordination. - increased self-confidence. - euphoria.

ethanol and mood

What effect does ethanol have on mood? The effect on mood varies among individuals, most becoming louder and more out-going, but some becoming morose and withdrawn. At high levels of intoxication, the mood tends to become more labile (flexible), with euphoria and melancholy, aggression and submission, often occurring successively.

different seizures

What's different about partial and complex seizures? Generalized seizure (entire cerebral cortex of both hemispheres) -tonic-clonic, absence, myoclonic, febrile, status epilepticus Partial seizure (circumscribed area of cortex) -simple, compex

withdrawal syndrome

Withdrawal syndrome describes the adverse effects, both physical and psychological that lasts for a few days or weeks, of ceasing to take a drug.

x-linked disorders

X-linked diseases: associated with the X chromosome in a male. examples: red-green color blindness, duchene muscular dystrophy, haemophilia

aromatase

a)Hormones produce masculinization of the male brain during development. These are not androgens! The brain does not have androgen receptors! The testosterone is FIRST transformed into estrogen by the enzyme aromatase and then binds to estradiol receptors in the brain

How does the Y chromosome produce masculinization of the brain and reproductive organs?

a)Hormones produce masculinization of the male brain during development. These are not androgens! The brain does not have androgen receptors! The testosterone is FIRST transformed into estrogen by the enzyme aromatase and then binds to estradiol receptors in the brain. b)Females escape the testosterone driven masculinization since they do not have a testosterone surge at early stages of development.

two lobes of hypothalamus

anterior (gland) and posterior (brain region).

PTSD

develops through exposure to a traumatic event such as the Holocaust, severe abuse, rape, natural disasters, and unnatural disasters. PTSD may immediately follow the traumatic event or it may occur months or even years later. 8% of men and 20% of women develop PTSD. Periods of symptom increase followed by remission or decrease - although for some symptoms may be unremitting and severe. Traumatic experiences include: combat and war-related traumas, sexual abuse and assault, natural disasters such as hurricanes and earthquakes, and unnatural disasters such as plane crashes and terrorist attacks.

functions of REM sleep

escribe the functions of dreaming and REM sleep. REM sleep: • Many cortical regions are at least as active during REM sleep as during waking. • During REM sleep, extrastriate visual cortical areas are highly activated (dreaming?), no corresponding increase in area V1. REM sleep: • Initiation of REM sleep: locus coeruleus (noradrenergic) and raphe nuclei (serotonergic) are silent, but cholinergic neurons in the pons are highly active. • Spinal motor neurons are inhibited.

four phases of sexual response cycle

excitement, plateau, orgasm, resolution

emotional experience vs emotional expression

expression- observable verbal and nonverbal behaviors emotional experience- is a complex psychophysiological experience of an individual's state of mind as interacting with biochemical (internal) and environmental (external) influences. In humans, emotion fundamentally involves "physiological arousal, expressive behaviors, and conscious experience."[1] Emotion is associated with mood, temperament, personality, disposition, and motivation. Motivations direct and energize behavior, while emotions provide the affective component to motivation, positive or negative.[2]

role of hypothalamus

maintenance of the body's internal environment in response to variations in the external environment.(e.g. body temperature, blood volume, blood oxygen) This occurs within narrow physiological ranges. Temperature-sensitive cells in the hypothalamus detect variations in brain temperature.

obsessive-compulsive disorder

obsessions causing anxiety or distress compulsions which in turn neutralize anxiety Behaviors can be repeated hundreds of times a day. Most of the individuals do not enjoy the ritualistic behavior, but they worry when they do not carry it out. • OCD runs in families→genetic component. • Frontal cortex or basal ganglia are active in individuals with OCD. • Depletion of serotonin. • Psychological factors: OCD usually occurs during a stressful life event. The first symptoms appear during childhood or adolescence OCD is equally common in males than in females OCD is sometimes accompanied by depression, eating disorders, and substance abuse. Anatomical substrate: Striatum: Caudate Putamen obsessions causing anxiety or distress compulsions which in turn neutralize anxiety Know that OCD has a genetic component, but is also considered a learned behavior. It is also possible to develop OCD after disease or injury has damaged the brain. Describe the basal ganglia and their role in anxiety disorders.

two ways of generating synchronicity

pacemaker, mutual coordination

gender-specific behaviors

self-assessment, societal expectations, genetics and hormones.

sham rage

sham rage is behavior such as biting, clawing, hissing, arching the back and "violent alternating limb movements" produced in animal experiments by removing the cerebral cortex.[1] It also describes rage seen in persons with hypothalamic brain lesions.[2 Sham rage: result of bilateral removal of the cerebral hemispheres, including the anterior hypothalamus. Additional lesion of the posterior hypothalamus abolishes sham rage.