Biological Correlatesof BehaviorAns

Biological Correlates
of Behavior
Answers

95. The answer is C. (Michels, vol 3, chap 42, pp 2, 3.) In the human brain, electrical impulses trigger chemical events. The release of presynaptic neurotransmitters stimulates postsynaptic receptors, allowing neuronal transmission to proceed. Synaptic communication between neurons is primarily chemical, which allows for the continuation of electrical impulses.
96. The answer is D. (Michels, vol 3, chap 59, pp 1-5.) Studies have reported that natural births are roughly a third more common at 3 AM than at 5 AM, and deaths 30 percent more common at 5 AM than at midnight. The timing of these events is thought to be directly related to biological rhythm. Body temperature follow a 24-hour rhythm, peaking at mid-afternoon. Depression has been linked to changes in the cortisol cycle. Personality disorders have not, to date, been linked to changes in the cortisol cycle. Personality disorders have not, to date, been linked to any biological rhythm.
97. The answer is C. (Michels, vol 3, chap 60, pp 12-13.) Although reports in the early 1960s suggested REM sleep deprivation as a cause of psychosis and anxiety, this is no longer believed to be true. REM sleep deprivation has not been shown to cause any psychopathologic symptoms in recent sleep studies. In fact, 50 percent of depressed patients “tested” with REM sleep deprivation improved with no other treatment.
98. The answer is C. (Zimmerman, Arch Gen Psychiatry 43:347-353, 1986.) The dexamethasone suppression test (DST) is the most widely used of the biological market tests for endogenous depression. Recent research by Zimmerman has shown its construct validity to be good in regard to the patient’s age, premorbid personality, history of suicide attempts, and cumulative life stress events. It is not good when using the patient’s family history of depression as a predictor.
99. The answer is B. (Michels, vol 2, chap 52, p 8. Pincus, ed 3. P270.) Cataplexy is the inability to carry out voluntary muscle movements while awake. It results from a sudden inhibition of muscle tone and varies from complete powerlessness to involvement of isolated muscle groups. It is frequently triggered by intense emotional states and lasts seconds to minutes. Neuroleptics are not used in its treatment.
100. The answer is A. (Kaplan, ed 4. P 644. Michels, vol 1, chap 55, pp 24 -25.) Tardive dyskinesia is a repetitive involuntary muscle movement of the lips, tongue jaw, neck, back, or extremities that is seen in some patients late in the course of treatment with antipsychotic medications. It often appears days to weeks after dru treatment is stopped. Its highest prevalence is seen in elderly females.
101. The answer is C. (Kaplan, ed 4. Pp 10-21 .) Lesioning and stimulation studies have shown that the hypothalamus exerts control over sleep, appetite, and sexual and emotional behavior. Hypothalamic hormones and other blood-borne factors can influence behavior; moreover, the release and action of these substances are affected by the neurotransmitters-norepinephrine, serotonin, and dopamine-that mediate behavior. Memory is a complex function that involves cortical and sub cortical structures and is affected by hypothalamic activity only in a secondary way.
102. The answer is C. (Kaplan, ed 4, pp 198, 199.) The most likely diagnosi for the man described in the question is an acute schizophrenic episode, although chronic abuse of hallucinogenic substances cannot be ruled out on the basis of the history given. Antipsychotic medications would be the drugs of choice for the treatment of this man. The two principal classes of antipsychotic drugs are the phenothiazines and the butyrophenones; two other classes are the thioxanthenes and the indoleamines.
103. The answer is C. (Kaplan, ed 4, pp 558-560. ) Stage 2 sleep constituted about 50 percent of total sleep time. It is characterized by a low-amplitude, fast frequency electroencephalographic pattern and sleep spindles of 12 to 16 cycles per second. Rapid eye movement (REM) sleep accounts for 20 to 25 percent of total sleep time; stage 3 and 4 for 20 percent; and stage 1 for 5 to 10 percent.
104. The answer is E. (Pincus, ed 3, p 179.) Temporal lobe lesions are associated with symptoms that can mimic psychiatric illness. These symptoms include affective states (such as anger or depression), depersonalization, and memory impairment. Because olfactory or gustatory hallucinations are relatively rare in psychiatric disorders, their presence should suggest organic disease. Automatisms are complex stereotyped behaviors carried out during psychomotor seizure activity.
105. The answer is B. (Kaplan, ed 4, pp 394.) Opiate withdrawal has been shown to be associated with increases in both the firing rate of the locus ceruleus, the major norepinephrine nucleus in the brain, and the concentration of 3-methoxy-4-hydroxyphenylglycol (MHPG), the major metabolite of brain norepinephrine. Moreover, when the drug clonidine is given in doses that decrease brain norepinephrine function, the symptoms of opiate withdrawal in methadone addicts have been successfully treated. Clonidine is thought to affect adrenergic receptors in the locus ceruleus.
106. The answer is D. (Kaplan, ed 4, pp 198-200.) Dopamine-β-hydroxylase converts dopamine to norepinephrine. There fore, a deficiency of this enzyme might be expected to result in decreased functional availability of norepinephrine and increased availability of dopamine. Observations have shown, in fact, that decreased availability of norepinephrine has been associated with flat affect and another symptoms of schizophrenia, and increased activity in dopaminergic systems has been associated indirectly with symptoms such as auditory hallucinations.
107. The answer is D. (Kaplan, ed 4, pp 199.) Antipsychotic medications are associated with extrapyramidal side effects, such as dyskinesia, akathisia, and symptoms similar to those of Parkinson’s disease. These side effects are thought to result from the blockade of dopamine receptors by the antipsychotic medications. The blockade, by causing a functional reduction in dopamine, produces a clinical picture similar to that of Parkinson’s disease, which is associated with an actual dopamine deficiency from degeneration of dopamine neurons.
108. The answer is E. (Kaplan, ed 4, pp 20-24.) The list of substances that mediate the transmission of nerve impulses at brain synapses is a growing one. Among the most well-known brain neurotransmitters are dopamine, norepinephrine, 5-hydroxytryptamine (serotonin), and γ-aminobutyric acid (GABA). 5-Hydroxyindoleacetic acid is a metabolite of serotonin.
109. The answer is A. (Pincus, ed 3, pp 54-55.) The frontal lobe syndrome is characterized by inappropriate social behavior and changes in affect. Affect usually is flattened, but modd may become euphoric, depressed, or hostile. Attention and perception aldo are impaired, leading to deficits in intellectual functioning.
110. The answer is E. (Kaplan, ed 4, pp 9-11.) Prospective longitudinal studies are studies in which individuals who are “vulnerable” (i.e., at high risk for psychiatric illness because of a positive family history) are identified at birth and followed over a period of time, Such studies are less subject to methodological bias than other approaches. For example, when compared with retrospective studies, prospective longitudinal studies tend to give a more accurate representation of early signs and symptoms of a given disorder and thus offer a better opportunity for the discovery of successful preventive approaches.
111. The answer is D. (Kaplan, ed 4, pp 22-23. Shopsin, Psychopharm Com 1:239-249, 1975.) α-Methylparatyrosine blocks tyrosine hydroxylase, which catalyzes the rate-limiting step in the synthesis of the catecholamines dopamine and norepinephrine. Administration of α-methylparatyrosine to humans causes a syndrome characterized by mild sedation to dysphoria.
112. The answer is C. (Kaplan, ed 4, pp 19.) Dopamine, serotonin, and norepinephrine, three of the most intensively studied neurotransmitters in the brain, actually act as transmitters at only a small number of central nervous system synapses. γ-Aminobutyric acid is thought to mediate transmission at 25 to 40 percent of synapses in various regions of the brain. Amino acids, including glycine, serve as neurotransmitters in a significant percentage of synapses in the spinal cord and brain.
113. The answer is D. (Kaplan, ed 4, pp 22.) The amino acid tyrosine is the precursor in the synthesis of dopamine and norepinephrine. Tyrosine is converted to 3,4-dihydroxyphenylalanine (dopa), which is then decarboxylated to dopamine. Through the action of the enzyme dopamine-β-hydroxylase, dopamine is converted to norepinephrine. According to current biochemical theories, this pathway is of critical importance in the pathogenesis of depression.
114. The answer is B. (Kaplan, ed 4, pp 19-21.) The locus ceruleus is a nucleus located in the pons. Call bodies in the locus ceruleus send axons, which are distributed in diffuse fashion, to the cortex and cerebellum. The neurons are noradrenergic—that is, they contain norepinephrine as their neurotransmitters substance.