Serotonergic neurotransmission

Hariri, A. R. Weinberger, D. R. (2003). Functional neuroimaging of genetic variation in serotonergic neurotransmission. Genes Brain Behav., 2(6), 341-9. 

Analogous to 5-HT ia KO mice, the neural mechanisms underlying increased anxiety-related behavior and reduced exploratory locomotion in mice with a disruption of the 5-HTT gene may relate to excess serotonergic neurotransmission which is expected to cause enhanced activation of postsynaptic 5-HT receptors. Both in vivo microdialysis in striatum and in vivo chronoamperom-etry in hippocampus revealed that 5-HTT null-mutant mice exhibit an approximately fivefold increase in extracellular concentrations of 5-HT and an absence of transporter-mediated clearance, although brain tissue 5-HT concentrations are markedly reduced by 40%-60% (Bengel et al. 1998). 

Parsons LH, Kerr TM, Tecott LH (2001) 5-HT(lA) receptor mutant mice exhibit enhanced tonic, stress-induced and fluoxetine-induced serotonergic neurotransmission. J Neu-rochem 77 607-617... 

Penalva RG, Flachskamm C, Zimmermann S, Wurst W, Holsboer F, Reul JMHM, Linthorst ACE (2002) Corticotropin-releasing hormone receptor type 1-deficiency enhances hippocampal serotonergic neurotransmission an in vivo microdialysis study in mutant mice. Nemoscience 109 253-266... 

While much emphasis has been placed on alterations in noradrenergic neurotransmission, TCA drugs are not without effect on serotonin (5-HT) neurotransmission. Long-term studies with TCA drugs in animals have demonstrated postsynaptic supersensitivity to serotonin (5-HTia) receptor agonists at serotonin synapses, with an associated enhancement of serotonergic neurotransmission. The sensitization to 5-HTia agonists is mediated in part by an increase in the density of postsynaptic 5-HTia receptors. Enhancement of trans-... 

Serotonin (5-hydroxytryptamine [5-HT]) pathways play an important role in postprandial satiety. Treatments that increase intrasynaptic serotonin or directly activate serotonin receptors tend to reduce food consumption, whereas interventions that dampen serotonergic neurotransmission or block receptor activation reportedly increase food consumption and promote weight gain (Blundell, 1984 Teibowitz, 1986). Moreover, CNS serotonin pathways have been implicated in the modulation of mood, impulse regulation and be-... 

The acute effects of ethanol and other sedative-hypnotics are mediated by actions at a number of receptor systems. For example, ethanol inhibits several excitatory receptor systems, including N-methyl-D-aspartate (NMDA) receptors, kainate receptors, and Ca channels. In addition, ethanol enhances the action of GABA at GABA receptors and appears to modulate serotonergic neurotransmission. Although a component of ethanol reinforcement is mediated by the activation of mesocorticolimbic dopamine neurons, activation of these neurons may not be necessary for ethanol reinforcement, as ethanol remains reinforcing in the absence of these neurons (Samson and Harris, 1992 Koob, 2000b). 

Bher P, de Montigny C Short-term lithium administration enhances serotonergic neurotransmission electrophysiological evidence in the rat CNS. Psychopharmacology 113 69-77, 1985... 

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