Psychopharmacology Flashcards
Translation of extracellular signals into a form that can be interpreted by complex intracellular enzymatic machinery is achieved through a relatively small number of cellular mechanisms. The transmembrane signaling systems that are multicomponent in nature and generate intracellular second messengers define which class of central nervous system (CNS) receptors?
G protein–coupled receptors
The rate-limiting enzyme in serotonin (5-HT) biosynthesis that has been extensively investigated in psychiatric disorders is
Tryptophan hydroxylase
Through the use of more precise molecular cloning and pharmacological and biochemical studies, seven distinct 5-HT receptor families have been identified, many of which contain several subtypes. Which of the 5-HT receptor types is an excitatory ionotropic receptor?
5-HT3
Which of the 5-HT1 receptor subtypes is found in particularly high densities in several limbic structures, as well as on serotonergic neuron cell bodies, where they serve as autoreceptors regulating 5-HT neuronal firing rates?
5-HT1A
The blockade of which of the 5-HT receptors has been implicated in the weight gain induced by certain psychotropic agents?
5-HT2C
Dopamine synthesis requires the transport of which of the amino acids across the blood–brain barrier?
L-tyrosine
Which of the dopamine receptor subtypes is of great psychopharmacological interest because of clozapine’s high affinity for this receptor?
D4 receptor
Which are the two major excitatory amino acids in the central nervous system (CNS)?
Glutamate and aspartate
Where are the majority of dopamine (DA) neurons located in the brain?
substantia nigra
The principal noradrenergic cell group, which has the largest group of norepinephrine (NE)–containing neurons in the mammalian brain, is the
Locus coeruleus
The highest concentration of serotonin (5-HT)–containing neurons in the mammalian brain is found in the
Raphe nuclei of the brain stem
Pyramidal cells, the predominant neurons of the cerebral cortex, utilize what as a neuro-transmitter?
Glutamate.
The projection neurons of the basal ganglia utilize what as a neurotransmitter?
GABA
Deficits in which of the neuropeptides have consistently been linked with Alzheimer’s disease?
Somatostatin. The hypothalamus and limbic regions such as the amygdala and hippocampus have large numbers of somatostatin-containing neurons.
The opening of which of the following ion channels is the mechanism through which GABA decreases neuronal activity?
Chloride.
Classic learned helplessness animal models have a high degree of validity as a model for depression in all of the areas except
Duration. In rats, learned helplessness persists only for several days, whereas depression in humans may last for months.
What neuroendocrine response is well-established in depression?
Overactivity of the HPA axis as manifested by an increase in cortisol secretion
Combat veterans with PTSD showed _____ suppression to dexamethasone challenge.
enhanced
Taking medications with meals will usually decrease the rate of drug absorption, leading to a decreased peak plasma concentration and prolonged time to reach the maximum plasma concentration. For which of the selective serotonin reuptake inhibitor antidepressants does food increase plasma concentra-tions and shorten the time to reach the maximum plasma concentration?
Sertraline.
Which of the cytochrome P450 (CYP) enzymes is found in high concentrations in the luminal epithelium of the small intestine and leads to extensive presystemic metabolism?
CYP3A4.
Nearly all medications used in clinical psychopharmacology are cleared partially or completely by metabolism, primarily in the liver. Which drugs are an exception?
lithium and gabapentin
What are Phase I clinical trials?
Phase I involves testing multiple doses of a drug for bioavailability, pharmacokinetics, and side effects.
What are Phase II clinical trials?
Phase II studies are dose-finding studies in patients with a given disorder.
What are Phase III trials?
Phase III generally includes pivotal double-blind trials for demonstrating efficacy and safety/tolerability.