CH 6 Flashcards
Almost all serotonergic neurons in the CNS are found along the ____ of the brainstem, associated with the ____ ____. The dorsal and _____ raphe nuclei give rise to most of the serotonergic fibers in the forebrain. 5-HT innervation of the forebrain is ____ than that of DA, comparable to ____. 5-HT producing cells also exist in the ____, thus drugs that interfere with 5-HT transmission may also have _____ effects
midline, raphe nuclei, median, greater, NE, gut, peripheral
5-HT’s molecular type is an ______.
Indolamine
The amino acid that is a precursor to 5-HTP and 5-HT
tryptophan
the enzyme that converts tryptophan to 5-hydroxyl-tryptophan (5-HTP); slow
tryptophan hydroxylase
the enzyme that converts 5-HTP to 5-HT
aromatic amino acid decarboxylase (AADC)
a drug that blocks 5-HT synthesis by irreversibly inhibiting tryptophan hydroxylase
parachlorophenylalanine (PCPA)
5-HT synthesis can be stimulated with large doses of ___ or ___. Tryptophan competes with other large, neutral ___ ___ for transport across the ____. The ____ of tryptophan to other aa’s determines the amount of 5-HT in made in the _______. A high carbohydrate diet which stimulates _____ release, can take aa’s out of the ______ and turn them into _______, with the exception of ______. This results in an increase in ______
tryptophan, 5-HTP, amino acids, BBB, ratio, brain, insulin, bloodstream, proteins, tryptophan, 5-HT
temporary reductions in 5-HT levels can be achieved in humans by giving an ____ _____ ______ (all aa’s minus tryptophan). Large, aa’s inhibit entry of the remaining tryptophan into the brain. It also stimulates ____ _____ in the liver, which further reduces level of _____ tryptophan, resulting in lower 5-HT ______ in CSF. Reducing 5-HT in this manner can cause ______ of symptoms in previously depressed patients but not ____ ones, and behavioural changes such as increased _____ in healthy subjects
amino acid cocktail, protein synthesis, plasma, metabolites, reappearance, healthy, impulsivity
5-HT is packaged by _____ like catecholamines and is thus sensitive to ______.
VMAT2, reserpine
The 5-HT transporter than removes 5-HT from the synapse via reuptake
SERT
the enzyme that breaksdown 5-HT into 5-HIAA
MAO
The metabolite of 5-HT that can be used as a measure for the activity of 5-HT neurons
5-HIAA
a drug that acts like amphetamine; reverses monoamine transporters to shoot 5-HT out into the synapse; was prescribed for appetite suppression in obese patients but caused cardiovascular side effects
fenfluramine
A recreational drug that acts on SERT with higher affinity than DAT and NET; can cause enhanced sensations and may be used as a therapeutic agent for PTSD
3,4-methylenedioxymethamphetamine (MDMA, ecstasy, molly)
drug that blocks SERT and thus acts as an SSRI
fluoxtine (prozac)
There are at least ____ different 5-HT receptors, and nearly all are ______. There are ___ main families. Many drugs are relatively _____. The 5-HT1 family has at least ___ subtypes while the _____ family has at least 3 subtypes. Our understanding of them are _______.
14, metabotropic, 7, nonselective, 5, 5-HT2, limited
The 5-HT1A receptor is concentrated postsynaptically in the ______, _____ and ______. They are somatodendritic autoreceptors in the ______. These receptors inhibit _____ and/or increase opening or _____ channels to hyperpolarize the cell
hippocampus, amygdala, septum, raphe, cAMP, K+