Electrophysiological changes in substantia nigra after dynorphin administration.
The present experiments were designed to explore the electrophysiological changes induced by dynorphin (Dyn) which was administered by pressure ejection into the zona reticulata of the substantia nigra (SNR). Dyn produced a long-lasting (6.0 +/- 4.5 min) decrease in firing rate in 70% of the cells recorded. Naloxone reversed the Dyn-induced decrease in firing rate in all cases, and also induced an increase in firing frequency on most occasions. Dyn did not alter cell activity in 8 of the 10 cells recorded in zona compacta of substantia nigra. It is concluded that Dyn exerts an inhibitory effect on SNR neurons, which appears to be pharmacologically specific since it is reversed by naloxone.
Lavin
A
A
Garcia-Munoz
M
M
D000818:Animals; D003864:Depression, Chemical; D004399:Dynorphins / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects; D013378:Substantia Nigra / Q000187:drug effects*
D011957:Receptors, Opioid; D004399:Dynorphins