Electrophysiological interactions between NMDA and phencyclidine/sigma receptor agonists and antagonists in Purkinje neurons in the cerebellum of the rat.
The purpose of this experiment was to study the electrophysiological interactions between phencyclidine and NMDA receptor agonists. Drugs were directly applied to cerebellar Purkinje neurons of urethane-anesthetized rats, through a multibarreled pipette by pressure ejection. Neuronal activity was recorded extracellularly. In almost all the cells encountered, NMDA-induced responses were stereospecifically blocked by phencyclidine/sigma agonists, such as: (+)PCMP[1-(1-phenyl cyclohexyl)-3-methyl piperidine] or dexoxadrol. However, quisqualate-mediated excitation was also antagonized by (+)PCMP, although quisqualate had a lower sensitivity to (+)PCMP than NMDA did. It was previously found that metaphit irreversibly blocked phencyclidine-induced responses in the cerebellum. It was found that metaphit attenuated phencyclidine-induced antagonism of NMDA responses. In conclusion, these findings suggested that phencyclidine/sigma agonists antagonized effects of NMDA and quisqualate, whereas the presence of an intact phencyclidine/sigma receptor was not essential for the NMDA-mediated response in the cerebellum.
Wang
Y
Y
Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan, Republic of China.
Lee
H K
HK
D000818:Animals; D002531:Cerebellum / Q000378:metabolism; D008297:Male; D016202:N-Methylaspartate / Q000008:administration & dosage / Q000494:pharmacology*; D009991:Oscillometry; D010622:Phencyclidine / Q000008:administration & dosage / Q000494:pharmacology*; D011689:Purkinje Cells / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000187:drug effects; D011957:Receptors, Opioid / Q000187:drug effects*; D017478:Receptors, Phencyclidine; D017480:Receptors, sigma
D017981:Receptors, Neurotransmitter; D011957:Receptors, Opioid; D017478:Receptors, Phencyclidine; D017480:Receptors, sigma; D016202:N-Methylaspartate; D010622:Phencyclidine