Penile erection and yawning induced by paraventricular NMDA injection in male rats are mediated by oxytocin.
The effect of N-methyl-D-aspartic acid (NMDA), (+-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA), or (+-)-trans-1-amino-1,3-cyclo-pentanedicarboxylic acid (ACPD) (5-60 ng in 0.3 microliter of saline) microinjected in the paraventricular nucleus of the hypothalamus on penile erection and yawning was studied in male rats. NMDA induced both penile erection and yawning in a dose-dependent manner. AMPA and ACPD also induced penile erection but less potently than NMDA, but were ineffective in causing yawning. NMDA effect on penile erection and yawning was prevented by (+)-MK-801 (0.05-0.1 mg/kg IP, 10 min before NMDA), by the oxytocin antagonist d(CH2)5Tyr(Me)-Orn8- vasotocin (50-100 ng ICV 10 min before NMDA), but not by haloperidol (0.1-0.5 mg/kg IP 10 min before NMDA). The results suggest that NMDA induces penile erection and yawning by increasing oxytocinergic transmission by acting in the paraventricular nucleus of the hypothalamus.
Melis
M R
MR
Bernard B. Brodie Department of Neuroscience, University of Cagliari, Italy.
Stancampiano
R
R
Argiolas
A
A
D000818:Animals; D003515:Cycloleucine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology; D007267:Injections; D007276:Injections, Intraventricular; D008297:Male; D016202:N-Methylaspartate / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009498:Neurotoxins / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology; D010121:Oxytocin / Q000502:physiology*; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology*; D010410:Penile Erection / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017459:Receptors, Amino Acid / Q000037:antagonists & inhibitors / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects; D015000:Yawning / Q000187:drug effects*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology
D009498:Neurotoxins; D017459:Receptors, Amino Acid; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D010121:Oxytocin; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D004298:Dopamine