5-hydroxytryptamine is a fast excitatory transmitter at 5-HT3 receptors in rat amygdala.
A fast excitatory synaptic potential mediated by 5-hydroxytryptamine (5-HT) was recorded in rat lateral amygdala neurons in brain slices. The synaptic potential has brief duration (tens of milliseconds), is mimicked by 5-HT, is potentiated by a 5-HT uptake inhibitor, and is blocked by selective 5-HT3 receptor antagonists. The underlying synaptic current reversed polarity at about 0 mV. This is an example of fast neurotransmission in the mammalian brain mediated by an amine rather than an amino acid. The antiemetic, anxiolytic, and perhaps antipsychotic actions of 5-HT3 antagonists might result from blockade of such synapses.
Vollum Institute, Oregon Health Sciences, University, Portland 97201.
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Sugita
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Shen
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North
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000200:Action Potentials / Q000187:drug effects; D000679:Amygdala / Q000502:physiology*; D000818:Animals; D004558:Electric Stimulation; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D017294:Ondansetron; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D011985:Receptors, Serotonin / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013569:Synapses / Q000502:physiology; D000077526:Tropisetron; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D007093:Imidazoles; D007211:Indoles; D011810:Quinoxalines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; C065783:GR 67330; D012701:Serotonin; D017294:Ondansetron; D005680:gamma-Aminobutyric Acid; D000077526:Tropisetron; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate