Low doses of gamma-hydroxybutyric acid stimulate the firing rate of dopaminergic neurons in unanesthetized rats.
In unanesthetized rats the intravenous (i.v.) administration of gamma-hydroxybutyric acid (GHB) at the doses of 50-400 mg/kg produced a dose-related stimulation (10-56%) of the firing rate of dopaminergic (DA) neurons in the pars compacta of the substantia nigra. Doses of 1000 and 1500 mg/kg inhibited the firing rate almost completely. In unanesthetized rats the intraperitoneal injection of GHB at the dose of 750 mg/kg produced a brief initial stimulation (23%) followed by a modest reduction in the firing rate (29%). On the other hand, in chloral hydrate-anesthetized rats the i.v. administration of GHB at cumulative doses of up to 200 mg/kg failed to modify the firing rate of DA neurons, while a cumulative dose of 400 mg/kg suppressed neuronal firing. The results indicate that sub-anesthetic doses of GHB stimulate the firing rate of DA neurons in unanesthetized rats.
Diana
M
M
Dipartimento di Neuroscienze B.B. Brodie, Università di Cagliari, Italy.
Mereu
G
G
Mura
A
A
Fadda
F
F
Passino
N
N
Gessa
G
G
D000768:Anesthesia, General; D000818:Animals; D004298:Dopamine / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012978:Sodium Oxybate / Q000008:administration & dosage / Q000494:pharmacology*; D013378:Substantia Nigra / Q000187:drug effects / Q000502:physiology*; D014851:Wakefulness
D012978:Sodium Oxybate; D004298:Dopamine