Serotonin depresses excitatory amino acid-induced excitation of cerebellar Purkinje cells in the adult rat in vivo

• Published in: Brain research Vol. 608; no. 1; p. 145
• Main Authors: Netzeband, J G, Weathers, L B, Strahlendorf, H K, Strahlendorf, J C
• Format: Journal Article
• Language: English
• Published: Netherlands 09-04-1993
• Subjects: Action Potentials - drug effects; Action Potentials - physiology; Amino Acids - antagonists & inhibitors; Animals; Cycloleucine - analogs & derivatives; Cycloleucine - pharmacology; Male; Microcomputers; Nervous System - drug effects; Purkinje Cells - drug effects; Purkinje Cells - physiology; Rats; Rats, Sprague-Dawley; Serotonin - physiology
• ISSN: 0006-8993
• DOI: 10.1016/0006-8993(93)90786-M

The modulatory effects of serotonin (5-HT) on excitatory amino acid (EAA)-induced excitations of Purkinje cells (PCs) were examined in urethane-anesthetized adult male rats using microiontophoresis and extracellular recordings. Application of 5-HT had minimal effects on the spontaneous firing rates of PCs but depressed excitations elicited by glutamate (Glu), aspartate (Asp), kainate (KA), and quisqualate (QA), and to a lesser extent those of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA). Excitations induced by the metabotropic EAA agonist, (+-)-1-aminocyclopentane-trans-1,3-dicarboxylate (t-ACPD), were unaffected by 5-HT. In summary, 5-HT depressed EAA-mediated excitations with the following rank order of effectiveness: Glu = Asp = KA = QA > AMPA >> t-ACPD. These findings suggest that 5-HT shows some selectivity in its modulation of EAA-mediated excitations of PCs and thus may serve an important neuromodulatory role in the cerebellum.