MSN 672 MODULE 4 PRACTICE EXAMINATION COMPLETE WITH VERIFIED ANSWERS

MSN 672 MODULE 4 PRACTICE EXAMINATION COMPLETE WITH VERIFIED ANSWERS 1. Which dopamine receptor subtype can function as both a presynaptic and postsynaptic receptor? A) D1 B) D2 C) D3 D) D4 Correct Answer: C) D3 Rationale: D3 receptors are unique among dopamine receptors in that they can be located both presynaptically and postsynaptically. Presynaptic D3 receptors function as autoreceptors that detect dopamine and inhibit further dopamine release, while postsynaptic D3 receptors are found in various brain regions including the limbic system. ________________________________________ 2. Blockade of postsynaptic D3 receptors in the limbic regions is thought to contribute to which therapeutic action? A) Antidepressant effects B) Antipsychotic effects C) Anxiolytic effects D) Mood stabilizing effects Correct Answer: B) Antipsychotic effects Rationale: Postsynaptic blockade of D3 receptors in the limbic regions contributes to antipsychotic actions. This is because the limbic system is involved in the pathophysiology of psychotic symptoms, and blocking D3 receptors in this area helps reduce these symptoms. ________________________________________ 3. Presynaptic D3 antagonism/partial agonism in the ventral tegmental area helps explain which therapeutic effect of cariprazine? A) Antipsychotic effects B) Mood stabilizing effects C) Antidepressant effects D) Anxiolytic effects Correct Answer: C) Antidepressant effects Rationale: The presynaptic actions of D3 antagonism/partial agonism in the ventral tegmental area explain cariprazine's antidepressant effects. By blocking presynaptic D3 autoreceptors, dopamine release is disinhibited, leading to increased dopamine transmission in the prefrontal cortex. ________________________________________ 4. What is thought to be deficient in mood, motivation, and cognitive symptoms of depression and in negative symptoms of schizophrenia? A) Dopamine release from mesocortical dopamine neurons B) Serotonin release from raphe nuclei C) Norepinephrine release from locus coeruleus D) Acetylcholine release from basal forebrain Correct Answer: A) Dopamine release from mesocortical dopamine neurons Rationale: Deficient dopamine release from mesocortical dopamine neurons is thought to contribute to mood, motivation, and cognitive symptoms of depression as well as negative symptoms of schizophrenia. This deficiency results in inadequate dopamine input to the prefrontal cortex. ________________________________________ 5. Presynaptic D3 receptors serve what function when they detect dopamine? A) Stimulate further dopamine release B) Inhibit further dopamine release C) Convert dopamine to norepinephrine D) Enhance dopamine reuptake Correct Answer: B) Inhibit further dopamine release Rationale: Presynaptic D3 receptors function as autoreceptors that detect dopamine levels in the synapse. When activated by dopamine, they inhibit further dopamine release through a negative feedback mechanism, helping to regulate dopamine neurotransmission. ________________________________________ 6. D3 receptors are present in the ventral tegmental area but are notably absent from which brain region? A) Nucleus accumbens B) Striatum C) Prefrontal cortex D) Hippocampus Correct Answer: C) Prefrontal cortex Rationale: D3 receptors are present in the ventral tegmental area (VTA) but are notably absent from the prefrontal cortex. This anatomical distribution is clinically significant because D3 antagonists/partial agonists have no direct effect in the prefrontal cortex where D3 receptors are absent. ________________________________________ 7. Postsynaptic D2 receptors in the prefrontal cortex are stimulated by which neurotransmitter? A) Serotonin B) Norepinephrine C) Dopamine D) Acetylcholine Correct Answer: C) Dopamine Rationale: Postsynaptic D2 receptors in the prefrontal cortex are stimulated by dopamine. This is an important pathway for dopamine signaling in the cortex, and D2 receptors in this region contribute to various cognitive and affective functions. ________________________________________ 8. How do D3 antagonists/partial agonists increase dopamine in the prefrontal cortex despite the absence of D3 receptors there? A) By directly stimulating D3 receptors in the prefrontal cortex B) By blocking D3 receptors in the ventral tegmental area, disinhibiting