Sensitivity of rubrospinal neurons to excitatory amino acids in the rat red nucleus in vivo.

Laboratoire de physiologie de la motricité, CNRS UA 385, Paris, France.
Neuroscience Letters (Impact Factor: 2.06). 01/1992; 134(1):49-52. DOI: 10.1016/0304-3940(91)90506-O
Source: PubMed

ABSTRACT Responses of rubrospinal neurons (RSNs) to iontophoretic applications of L-glutamate (L-Glu), L-aspartate (L-Asp), quisqualate (Quis) and N-methyl-D-aspartate (NMDA) have been studied in the rat red nucleus (RN) in vivo. All agonists produced a dose-dependent increase of the firing rate and Quis was found to be the most efficient. The responses to NMDA and to a lesser extent to L-Asp were abolished by steady application of 2-amino-5-phosphonovalerate (2APV) whereas responses to Quis were unaffected and those to L-Glu poorly antagonized. On the other hand, NMDA-mediated excitations were insensitive to steady application of 6,7-dinitroquinoxaline-2,3-dione (DNQX) which abolished responses to Quis and to a lesser extent to L-Glu while those to L-Asp were less affected. These results show the presence of both NMDA and non-NMDA receptors on RSNs in the rat. A specific localization of the NMDA receptors on distal dendrites of these neurons is suggested.

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