Cannabinoids modulate synaptic activity in the rat supraoptic nucleus.
In the present study, we investigated the effects of the cannabinoid receptor agonist CP55,940 on excitatory and inhibitory synaptic transmission in the rat supraoptic nucleus. Whole-cell patch clamp recordings were performed on supraoptic neurones in in vitro brain slice preparations. CP55,940 significantly reduced the frequency of spontaneous excitatory and inhibitory postsynaptic currents in a concentration-dependent manner. These changes were potently reversed by the CB1 receptor antagonist AM251. The results indicate that cannabinoids modulate the activity of magnocellular neurosecretory neurones by presynaptic inhibition of both excitatory and inhibitory synaptic transmission.
Soya
A
A
Deparment of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
Serino
R
R
Fujihara
H
H
Onaka
T
T
Ozaki
Y
Y
Saito
T
T
Nakamura
J
J
Ueta
Y
Y
D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D002186:Cannabinoids / Q000494:pharmacology*; D003511:Cyclohexanols / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects; D018408:Patch-Clamp Techniques; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors; D017661:Receptors, Presynaptic / Q000187:drug effects; D013495:Supraoptic Nucleus / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects*; D013779:Tetrodotoxin / Q000494:pharmacology
D000779:Anesthetics, Local; D002186:Cannabinoids; D003511:Cyclohexanols; D010880:Piperidines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D017661:Receptors, Presynaptic; C103505:AM 251; D013779:Tetrodotoxin; C054649:3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol