Evidence for serotonin as a possible inhibitory transmitter in some limbic structures
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Summary
Cats were used for microelectrode recording from single cells in the amygdaloid complex, and for fluorescence histochemical demonstration of monoamines. It was found that the firing rate of amygdaloid neurones decreased sharply following the administration of 5-HTP, the precursor of serotonin. Conversely, it increased after the administration of L-DOPA, the precursor of dopamine and norepinephrine. The fluorescence microscopy studies, after formaldehyde condensation, showed the presence of what appear to be axosomatic synapses containing serotonin on amygdaloid and hippocampal neurones. We conclude that serotonin may be an inhibitory synaptic transmitter in these limbic structures.
Key words
Cats Amygdala Hippocampus Serotonin SynapsesPreview
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References
- Andersen, P., J.C. Eccles and Y. Løyning: Location of postsynaptic inhibitory synapses on hippocampal pyramids. J. Neurophysiol. 27, 592–607 (1963).Google Scholar
- Blackstad, T.W., and P.R. Flood: Ultrastructure of hippocampal axosomatic synapses. Nature (Lond.) 198, 542–543 (1963).Google Scholar
- Bogdanski, D.F., H. Weissbach and S. Udenfriend: Pharmacological studies with the serotonin precursor, 5-hydroxytryptophan. J. Pharmacol. exp. Ther. 122, 182–194 (1958).Google Scholar
- Brookhart, J.M., A. Arduini, M. Mancia and G. Moruzzi: Thalamocortical relations as revealed by induced slow potential changes. J. Neurophysiol. 21, 499–525 (1958).Google Scholar
- Dahlström, A., and K. Fuxe: Evidence for the existence of monoamine-containing neurons in the central nervous system. I. Acta physiol. scand. 62 (suppl.), 232, 1–55 (1964).Google Scholar
- Eidelberg, E., M.K. Miller and M. Long: Spectrum analysis of electroencephalographic changes induced by some psychoactive agents. Int. J. Neuropharmacol. 5, 59–74 (1966).Google Scholar
- Falck, B., N.-A. Hillarp, G. Thieme and A. Torp: Fluorescence of catecholamines and related compounds condensed with formaldehyde. J. Histochem. Cytochem. 10, 348–354 (1962).Google Scholar
- Herz, A., u. A.C. Nacimiento: Über die Wirkung von Pharmaka auf Neurone des Hippocampus nach mikroelektrophoretischer Verabfolgung. Naunyn-Schmiedebergs Arch. exp. Path. Pharmak. 251, 295–315 (1965).Google Scholar
- Kandel, E.R., and W.A. Spencer: Electrophysiology of hippocampal neurons. II. After-potentials and repetitive firing. J. Neurophysiol. 24, 243–259 (1961).Google Scholar
- Kubota, K., H. Sakata, K. Takahashi and M. Uno: Location of the recurrent inhibitory synapse on cat pyramidal tract cell. Proc. Japan Acad. 41, 195–197 (1965).Google Scholar
- Schanberg, S.M.: A study of the transport of 5-hydroxytryptophan and 5-hydroxytryptamine (serotonin) into brain. J. Pharmacol. exp. Ther. 139, 191–200 (1963).Google Scholar
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