Which of the following statements is true about the impact of hormonal changes on aggression Quizlet
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True or false: Physiological tolerance causes neuronal plasticity within the brain to lessen the effects of a drug. WHY? False. Physiological tolerance occurs when the liver becomes more efficient at breaking down the substance. Which of the following is TRUE regarding deltaFosB? a. DeltaFosB levels decrease within 12 hours. b. It is a transcription factor that increases expression following acute administration of drugs. c. It's accumulation in the brain only occurs following administration of drugs of abuse. d. It turns on gene expression. WHY? D. It turns on gene expression. Transcription factors control gene expression! Which of the following is FALSE? a. Nicotine increases release of glutamate from the prefrontal cortex. b. Excitatory inputs to the ventral tegmental area (VTA) causes an increase in dopaminergic release in the nucleus accumbens. c. Excitatory inputs onto GABAergic neurons increases dopamine release by the ventral tegmental area. d. Cocaine blocks reuptake of dopamine into ventral tegmental area terminals. WHY? C. Activity at GABAergic neurons DECREASES release of dopamine from the VTA neurons. Opiates, THC, and Alcohol INHIBIT activity of GABA neurons, thereby leading to an INCREASE in dopamine release from the VTA.. True or false: Blocking GABA receptors in rodents is an effective means of preventing alcohol intoxication. WHY? True. The drug R015-4513 blocks the GABA receptor and prevented the effects of alcohol. True or false: The changes in D2 receptor expression seen in individuals that abuse cocaine last for 2-4 weeks. WHY? False. The data shown in class indicates that the D2 receptor levels are changed for at least 4 months. The presence of XX chromosomes..... a. results in the development of ovaries that release estrogens and progestins during prenatal development. b. increases the likelihood of developing X-linked disorders. c. normally results in an increase in the size of the sexually dimorphic nucleus of the preoptic area (SDN-POA). d. results in ovaries in adulthood that secrete higher concentrations of estrogens and progestins. WHY? D. The ovaries do not release hormones during development! True or false: Steroid hormones are derived from cholesterol and are hydrophilic. WHY? False. This statement is FALSE. Steroid hormone are lipophilic, NOT hydrophilic! Which of the following statement is FALSE? a. The presence of a Y chromosome signals the formation of testes. b. The XO genotype is not compatible with life. c. The YO genotype is not compatible with life. d. An individual with an XXY genotype has a male appearance. WHY? B. This statement is FALSE. The XO genotype is seen in Turner Syndrome. DHT.... a. binds to the testosterone receptor. b. is converted from testosterone via activity of aromatase. c. is responsible for the masculinization of the brain. d. has high circulating levels during prenatal development. WHY? D. It binds to the androgen receptor. True or false: The sexually dimorphic nucleus of the preoptic area (SDN-POA) is sensitive to circulating hormone levels around the time of birth. WHY? True. Injection of testosterone around the time of birth in females, masculinizes the structure of the SDN-POA. What is deltaFosB? Transcription factor How are deltaFosB levels affected by addiction? Accumulates in the brain areas associated with addiction/reward following chronic administration Can alter multiple target genes for long periods of time following drug cessation! Regardless of the drug, addicts have ______________ amounts of _____ receptors measured through PET scan in the brain. How long do these changes in plasticity last? lower; D2; at least 4 months post-exposure How does cocaine act in the reward system? Blocks the DAT How do amphetamines act in the reward system? Look like DA ("false neurotransmitter"), increases release of DA from VTA neurons, reverses DAT How do opioids act in the reward system? (morphine, heroin) Bind to GABA neurons, causing hyperpolarization, suppressing GABA release at VTA neurons. Now, DA is not inhibited, so it floods dopaminergic systems. How does alcohol act in the reward system? Increases DA release, inhibits firing of GABA neurons that synapse onto VTA neurons How does nicotine act in the reward system? Mimics ACh, binding to nicotinic ACh receptors (excitatory) on VTA neurons, causing an increase in DA release, and also increases glutamatergic activation of VTA neurons How does marijuana (THC) act in the reward system? Inhibits activity of GABA neurons that synapse on the VTA Varenicline (Chantix) is a drug that blocks nicotinic ACh receptors in the mesolimbic dopamine reward pathway. This drug is used to treat nicotine addiction. It works by blocking nicotinic ACh receptors localized to... a. GABA interneuron nerve terminals in the VTA C What is drug sensitization? With sensitization, the same dose of drug produces a stronger response/action. If that action is the motivation to take drugs, continued drug use makes it progressively more difficult to quit. What happens to rats given amphetamine for the first time versus after repeated doses? Sensitization; Animals with prior exposure to amphetamine show greater activity to amphetamine than do rats getting amphetamine the first time. Even 1 year later without further drugs, the amphetamine-treated rats are still sensitized! How many types of drug tolerance are there? What are they? Physiological Tolerance: The liver gets more efficient at breaking down the drug before it gets to the brain. Cellular Tolerance: Plasticity in neurons makes them less responsive to drugs. How is drug tolerance measured in rats? What are the results? A hot light is directed at a rat's tail and time to flick its tail away from the light is a measure of pain. Morphine decreases pain, but its pain killing action is lost after several days of treatment. Does tolerance indicate drug dependence? No What does drug tolerance lead to? Drug tolerance leads to a new homeostatic 'set point' required to obtain feelings of euphoria from the drug What is drug dependence associated with? Dependence associated with withdrawal (absence of drug disturbs homeostasis) Which of the following statement describes drug tolerance? a. Decrease in
the effect of a drug after repeated use. D. all of the above What is different about the U.S. way of treating drug addiction versus other countries? Cultural differences in treatment- the US generally follows a "complete drug abstinence" model, whereas other countries simply attempt to reduce drug taking so that it doesn't interfere with addict's life Why are drug addicts prone to relapse? Due to persistent changes in the brain, drug addicts are prone to relapse What are the steps in U.S. drug treatment? Step 1. Detoxification- Getting the drug out of the body- can either come with time, or be aided by medication (i.e. methadone for heroin addicts, benzodiazepines for alcoholics) Step 2. Maintaining Abstinence- methadone used for heroin addicts (known methadone-related deaths). Step 3. Behavioral Therapy (support groups, incentive programs, acupuncture) What is R015-4513? blocks the GABA receptor through which alcohol exerts its effects... Animals given the drug could ingest toxic amounts of alcohol and show no impairments What is the difference in sex vs. gender? Sex: Gender: What is the SRY gene? Sex-determining Region of the Y chromosome; codes for the protein "testis-determining factor" (TDF) Which of the following is FALSE? a. The Y chromosome contains less genes than the X chromosome D. (They have only 1 of each chromosome) What is Klinefelter Syndrome? XXY What is Turner Syndrome? XO What is XYY Syndrome? -"Male" appearance What is XXX Syndrome? -"Female" appearance Which brain areas control expression of sex behavior in males versus females? MALES: FEMALES: Which part of the hypothalamus has sexual dimorphism in rodent brains? Sexually Dimorphic Nucleus of the PreOptic Area
(SDN-POA) Interstitial Nucleus of the Anterior Hypothalamus-3 (INAH-3) in humans What are sex steroids? -Produced by ovaries or testes ***Both sexes have estrogens and androgens!!!!! Sex steroids in males -Higher concentrations of
androgens Sex steroids in females -Higher concentrations of estrogens 5-alpha-reductase converts ____________ into _____________ Testosterone; DHT Aromatase converts ____________ into ___________ Testosterone; 17-beta-estradiol Steroid hormones are ______philic and act by binding to ______________ receptors Lipophilic (can cross cell membranes); steroid receptors Progesterone binds to..... Testosterone and DHT bind to...... Estradiol binds to....... -Progesterone Receptor (PR) -Androgen Receptor (AR) -Estrogen Receptor (ER) Two types of steroid hormone signaling 1. "Classical" mechanism of action is via nuclear receptors (genomic) 2. Steroid hormones also act through membrane-bound receptors (more rapid effects) True or false: Testosterone in the blood easily passes through every cell membrane in the body True; but doesn't ACT in every cell in the body Steps of sexual differentiation in development 1. The presence of a Y chromosome will direct indifferent gonads to develop as testes. 2. Without a Y chromosome, the indifferent gonads develop as ovaries. 3. Hormones from the fetal testes masculinize the body, and the brain (at least in nonhuman animals) 4. The fetal ovaries do not secrete androgens, so the body develops in a feminine fashion, as does the brain How is the brain female "by default"? The female to male transition of the brain is believed to occur via the actions of estradiol (estradiol is converted into testosterone in the brain by aromatase) Organizational versus Activational effects of steroid hormones and sexual differentiation Organizational: early in life, irreversible Activational: post-pubescent, reversible Organizational effects of gonadal hormones during development -Permanent change in nervous system structure that leads to permanent change in function -Occur during sensitive periods of neural development Activational effects of gonadal steroid hormones Transient, come and go with presence or absence of hormones Which of the following is an example of the activational effects of hormones? a. The presence of the SRY gene signaling to make testes C How chromosomes and hormones determine brain and appearance MALES: FEMALES: Organizational vs. Activational effects of Steroids on Sexual Behavior ______________ is responsible for masculinizing the brain and ________________ is responsible for masculinizing the body. a. testosterone; DHT C-->estradiol is most DIRECTLY responsible What is androgen insensitivity syndrome? Testicular Feminization Syndrome XY individuals with undescended (but fully functional) testes, and the presence of a vagina Lack of functional androgen What is Congenital Adrenal Hyperplasia (CAH) XX genotype with excess androgen production by adrenal glands during fetal development Have normal ovaries and no testes Masculinization of external genitalia to varying degrees (ambiguous sex) Usually medically treated and raised as girls CAH females more likely to be interested in "boys" toys and to be described as 'tomboys' Higher percentage of homosexuals in CAH population... but be careful about drawing conclusions about causes of human behavior What is "Guevedoces"? Lack of DHT due to deficiency in 5a-reductace enzyme DHT essential for development of male external genitalia XY Individuals
with At puberty, the surge in testosterone production overcomes the 5-alpha reductase enzyme deficiency, resulting in the growth of the male sex organs.... and the "girls" become "men" Activational effects of estradiol unrelated to sexual behavior Increases number of dendritic spines on hippocampal neurons Enhances spatial memory May protect against stroke, Alzheimer's Disease, Parkinson's Disease Beneficial effects of post-menopausal hormone replacement therapy may depend on when hormone replacement therapy is begun and health of the brain Activational effects of steroid hormones unrelated to sex behavior Estradiol/Progesterone administration increases dendritic spine density Neurochemistry of Reproductive Behavior-
Prairie versus Montane voles: Prairie are monogamous, Montane are promiscuous Prairie voles are highly social and form pair bonds after mating. Montane voles are less social and do not form pair bonds. Test with partner/stranger/empty chamber: Which two hormones are important in pair-bonding in voles? Vasopressin (MALES): Oxytocin (FEMALES): Changing Vasopressin Receptor Expression in voles...... -When Vasopressin receptors were virally overexpressed in the Ventral Pallidum (VP) of the Montane vole, it caused Montane voles to act like Prairie voles Why is oxytocin the 'love' neurotransmitter? Implicated in sexual arousal, child bonding, maternal behavior, increases during orgasm in both males and females, pair-bonding True or false: Oxytocin injected into the ventral pallidum of female montane voles would increase pair bond formation False-NAc Basic, universal emotions: Anger, disgust, fear, happiness, sadness, surprise The _________ is more activated in fear, and the _______________ is more associated with sadness Amygdala; Medial prefrontal cortex What is a system? A collection of brain areas that work together towards a certain function What is the "Limbic Lobe"? Who first described it? Paul Broca; Cingulate gyrus/cortex on the medial surface of the temporal lobe/Hippocampus What is the Papez Circuit? -Link between the cortex and the hypothalamus Neocortex (emotional coloring)<--> The hypothalamus is responsible for ________________ of emotion Behavioral expression What is Kluver-Bucy Syndrome? -Temporal lobectomy on rhesus monkeys, which caused changes in aggressive behavior and responses to fearful situations -Poor visual recognition (needed to place items in mouth) The same symptoms of Kluver-Bucy Syndrome have been observed in humans with __________________ lesions and lesions to the ____________. Humans display____________ Temporal lobe; amygdala; 'flattened emotions' An increase in amygdala activation would likely lead to.... a. An increased fear response A 3 groups of amygdala nuclei. What information feeds into the amygdala? 1. Basolateral nuclei 2. Corticomedial nuclei 3. Central nucleus Information from all sensory systems feed into the amygdala (especially the basolateral nuclei) Symptoms experienced by S.M. (30 yo woman with bilateral lesions to the amygdala) -Normal intelligence Electrical stimulation of the _________ amygdala causes piloerection in cats (increase in fearful and violent aggressive responses). In humans, causes _______________ Lateral; increases in anxiety and fear Learned fear conditioning experiment Tone 1 paired w/ mildly painful foot shock, Tone 2 was benign Sensory signals go to the basolateral nuclei of the amygdala, which gets relayed to the central nucleus of the amygdala Plasticity of the synapses in the basolateral amygdala, so that the tone (by itself harmless), now elicits an enhanced fear response Lesions of the amygdala eliminates these learned visceral responses Diagram of learned fear Testosterone administered to an adult rat that was NOT exposed to estradiol around the time of birth would............... WHY? a. produce a masculinized SDN-POA. b. produce lordosis behavior. c. produce mounting sexual behavior. d. produce no sexual behavior. Produce NO sexual behavior **If the brain has been feminized, testosterone administration will not produce any sex behavior effect. True or false: the genotypic sex matches the gonadal sex of individuals with androgen insensitivity syndrome. True What enzyme is important in producing masculinization of the body? Explain. a. 5-alpha reductase b. aromatase c. androgens d. estradiol a. 5-alpha reductase is responsible for the conversion of testosterone into DHT. DHT is critical in the development of the external male genitalia. True or false: Individuals with congenital adrenal hyperplasia have male gonads. True Which of the following statements is TRUE? a. Intra-nucleus accumbens injection of a vasopressin antagonist in male montane voles produces pair-bond formation. b. Both vasopressin and oxytocin are sex steroid hormones that are critical in pair-bond formation. c. oxytocin receptor expression is higher in the nucleus accumbens of male prairie voles compared to male montane voles. d. Administration of oxytocin to female prairie voles increases pair-bond formation d. True or false: There is no overlap in brain activity associated with viewing images of one's children and one's romantic partner as measured through fMRI. EXPLAIN. False. There is overlap in the striatum (reward brain areas) Which of these symptoms would you NOT expect from an individual with Kluver-Bucy Syndrome? EXPLAIN WHY THIS STATEMENT IS FALSE. a. Increased interest in sex. b. Decreased aggression. c. Increased fear. d. Decreased visual recognition. C. You would expect them to have a DECREASE in fearful responses True or false: There is an increase in amygdala activation when shown fearful faces. True. Which of these statements is CORRECT? a. The corticomedial nuclei are dorsal to the basolateral nuclei of the amygdala. b. The amygdala is not found bilaterally. c. The amygdala is found in the frontal lobe. d. The amygdala is located laterally in the temporal lobe. a. True or false: The hypothalamus in the Papez circuit is critical in the behaviors associated with emotion. True How are sensory signals relayed through the amygdala to produce enhanced fear response? Sensory signals go to the basolateral nuclei of the amygdala, which gets relayed to the central nucleus of the amygdala plasticity of the synapses in the basolateral amygdala so that the tone (by itself- fear conditioning experiment) now elicits an enhanced fear response The central nucleus of the amygdala projects to the ____________ to create an autonomic response hypothalamus The central nucleus of the amygdala projects to the ____________ to create a behavioral reaction Periaqueductal gray matter in the brain stem The central nucleus of the amygdala projects to the ________________ to create an emotional experience Cerebral cortex
The central nucleus of the amygdala projects to the hypothalamus to create __________ an autonomic response The central nucleus of the amygdala projects to the periaqueductal gray matter of the brain stem to create ____________ a behavioral reaction The central nucleus of the amygdala projects to the cerebral cortex to create ________________ an emotional experience Considering this last experiment we discussed.... a. Tone info gets relayed to the basolateral amygdala b. The hypothalamus is responsible for the increased heart rate in the rabbits c. The electric foot shock is relayed to the central nucleus of the amygdala d. Experience-dependent plasticity is responsible for pairing the tone/shock with the behavioral response in the rabbits C. gets relayed to the basolateral nucleus Describe the experiment and results studying the role of the amygdala in learned fear in humans -PET scans in humans viewing emotionally charged versus neutral scenes -Emotionally charged scenes were both pleasant and unpleasant; neutral images were of plants/household scenes -***More activity in the amygdala when viewing emotionally charged images than neutral images -***Task in identifying which pictures they had seen in the initial part of the experiment- more accurately identified emotionally charged images than neutral ones, which correlated with amygdala activity Anger is ___________, and aggression is _____________ emotion, behavior What is one factor affecting aggression? Circulating androgen level -increases in androgens correlate to increased behavior; castration (removal of the testes) can reduce aggressive behavior Bilateral removal of the amygdala makes animals ____________________ More docile What happens when you remove the entire cerebral cortex with the hypothalamus left intact? Sham rage What happens when you remove the entire cerebral cortex AND the ANTERIOR hypothalamus? Sham rage What happens when you remove the entire cerebral cortex AND the anterior hypothalamus AND the posterior hypothalamus? NO sham rage Electrical stimulation of the MEDIAL hypothalamus elicits _______________ in cats Threat attack- threatening behaviors, but the cat didn't usually attack the rat Electrical stimulation of the LATERAL hypothalamus elicits _______________ in cats Silent biting attack- not exaggerated threatening behaviors, rather the cat quickly and viciously attacked the rat's neck What does EEG measure? -The electrical activity of a large population of neurons -Records general activity of cortex measured as fluctuations in voltage (~10mircovolts) -Need thousands of neurons in order to generate a signal large enough to read What is MEG? Magnetoencephalography -Newer technology than EEG, measures magnetic signals generated by neural activity -Better localization than EEG, but requires a specialized element What is measured in EEG? -Electrical fields generated by pyramidal neurons of the cortex What does a higher EEG amplitude indicate? More synchronous activity What does EEG frequency indicate? How often neural synchrony occurs What do EEG rhythms correlate with? Behavioral states (wakefulness, sleep, attentiveness, pathology) Higher EEG FREQUENCIES are associated with ____________, while slower frequencies are associated with ____________ Wakefulness; sleep Higher EEG AMPLITUDES are associated with ____________, while slower frequencies are associated with ____________ Sleep, wakefulness What are delta rhythms associated with? Deep sleep What are theta rhythms associated with? Both sleep and wakefulness What are alpha rhythms associated with? Quiet wakeful states, largest over the occipital lobe What are mu rhythms associated with? Similar to alpha waves, but largest over motor and sensory cortices
What are beta rhythms associated with? 15-30 Hz What are gamma rhythms associated with? Being attentive What are two ways of creating synchronous activity? 1. A pacemaker can generate the rhythm for rhythmical cortical activity 2. Rhythms can also be intrinsically generated by the collective behavior of all the participants Which brain area functions as a pacemaker? Thalamus How does a 2 Neuron Oscillator create rhythmic activity? -Circuits of neurons generate rhythmic activity -Tonically active excitatory input to excitatory cell (E) -E fires on inhibitory cell (I) -Activity trades back and forth between the excitatory and inhibitory neurons How does a 1 Neuron Oscillator function? -Thalamic neurons can generate rhythmic activity even in the absence of rhythmic input!! -A small group of thalamic neurons have intrinsic properties that allow them to generate rhythmic activity -The rhythms created by the thalamus (small # of cells) generate rhythms in the cerebral cortex (large # of cells) What is sleep? A readily reversible state of reduced responsiveness to, and interaction with, the environment What are the two theorized purposes of sleep? -Restoration: rest and recover -Evolutionary adaptation: keep out of trouble and avoid predators What are the stages of sleep and their manifestations in EEG? -Wakefulness: high frequency, low amplitude -Non-REM (Slow Wave Sleep): lower frequency, higher amplitude, brain is idling -Rapid Eye Movement (REM) (paradoxical sleep): wave forms are more similar to wakefulness than Slow Wave Sleep, associated with dreaming What happens to the body during Non-REM sleep? Period of rest, muscle tension decreased, movement is minimal Body is CAPABLE of movement, but movement is suppressed by the brain What happens to the body during REM sleep? Dreaming sleep, brain waves look more like the awake brain, periods of rapid eye movement How does sleep progress? Gradual progression from awake through deeper and deeper stages of Non-REM Slow Wave Sleep How often does REM sleep occur? Periodically throughout the night (~90 minutes) and bouts get longer as the night goes on What is muscle atonia and its relationship to sleep? Paralysis; occurs during REM sleep so that the body cannot act out its dreams "Hallucinating brain in a paralyzed body" What happens physiologically during REM sleep? Breathing becomes rapid, irregular, and shallow Increases in blood pressure and heart rate When is sleep walking/talking possible? During Non-REM sleep What is the term for sleep walking? Somnambulism Which of these statements are FALSE? a. More time is spent in REM sleep at the end of the sleep period b. REM sleep is associated with increased heart rate and increased brain activity c. Sleep walking occurs during REM sleep from "acting out" dream d. Dreams are associated with REM sleep C Is there something special about REM sleep? What are 3 theories proposed by Freud, Hobson & McClarley, and Karni about why REM sleep is important? Freud: wish fulfillment Hobson & McCarley: random activation of associations and memories that the cortex tries to synthesize Karni: memory consolidation What is the Recuperation theory of sleep? -Based on the personal perspective that at the end of the day we become tired, and when we awaken from sleep, we feel refreshed -Hypothesis is that bodily resources are depleted throughout the day and must be replenished through sleep What is the Biological Adaptation theory of sleep? -Predator or prey? Predators can sleep at ease, while prey's sleep is reduced for protection -Nocturnal or diurnal? We sleep when we cannot travel as easily What happens to humans deprived of sleep? -1 night of 3-4 hour deprivation: increased sleepiness, disturbances on written tests of moods, perform poorly on tests of vigilance, where concentration is needed -2-3 days of deprivation: microsleeps |
