Abstract
Synaptically released dopamine is known to evoke fast as well as slow synaptic potentials in neurones of gastropod molluscs. Here evidence is presented that the fast excitatory response to dopamine is mediated by the direct activation of a ligand-gated channel: unitary currents were observed in outside-out patches of neurones exposed to dopamine, and the response persisted in the presence of intracellular guanosine 5'-o-(2-thiobiphosphate), GDP[beta-S], a condition known to block G-protein-coupled responses to dopamine and other agents. In whole-cell recordings, the fast response desensitized very rapidly; it was less desensitized in outside-out patches, suggesting dependence of desensitization on an intracellular factor. The response to dopamine was blocked by D-tubocurarine and strychnine (both probably by channel blockade), by apomorphine, chlorpromazine and relatively high doses of (+/-)-sulpiride and spiperone. The channel conducts predominantly monovalent cations. Unexpectedly, the fast response to dopamine was also observed in an identified dopaminergic neurone when maintained in isolation in culture. The receptors on the dopaminergic neurone were unevenly distributed, being more abundant on the axon-hillock, axon and ne...Continue Reading
References
Jan 15, 1979·Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character·M S Berry, G A Cottrell
Jan 1, 1992·Neuron·S VerninoJ A Dani
Apr 15, 1992·Biological Psychiatry·R D Todd
Jul 1, 1990·Pflügers Archiv : European journal of physiology·G A CottrellN W Davies
Jul 16, 1987·Nature·C D Benham, R W Tsien
Jun 29, 1989·Nature·R C Hardie
Jun 29, 1989·Nature·V DerkachR A North
Jul 1, 1989·Trends in Neurosciences·S A Lipton, S B Kater
Oct 1, 1989·Proceedings of the National Academy of Sciences of the United States of America·T S McClintock, B W Ache
May 1, 1989·British Journal of Pharmacology·J J LambertJ Dempster
Aug 15, 1986·European Journal of Pharmacology·H C NeijtJ Van den Bercken
Aug 1, 1972·The Journal of Physiology·P Ascher
Aug 25, 1983·Nature·C E Jahr, T M Jessell
Oct 1, 1994·Pflügers Archiv : European journal of physiology·K A GreenG A Cottrell
Jun 1, 1993·Trends in Neurosciences·J M Lauder
Jan 1, 1995·Experimental Physiology·S J Harris, G A Cottrell
Citations
May 7, 2005·Neuroscience and Behavioral Physiology·V V AndrianovL N Muranova
Mar 16, 2004·Neuroscience Letters·Michael R DueKlaudiusz R Weiss
Oct 1, 1996·British Journal of Pharmacology·K A GreenG A Cottrell
Jun 30, 2006·Neuroscience·K S DobsonG E Spencer
Nov 13, 2004·Journal of Neurophysiology·Manuel Díaz-Ríos, Mark W Miller
Aug 1, 1997·Journal of Neurophysiology·E M QuinlanA D Murphy
Nov 23, 2006·The Journal of Experimental Biology·Oliver R BraubachRoger P Croll
May 12, 2009·Molecular and Biochemical Parasitology·Vijayaraghava T S RaoSean G Forrester