The related roles of dopamine and glutamate in the initiation of 50-kHz ultrasonic calls in adult rats.
Effects of amphetamine on the production of 50-kHz ultrasonic calls were studied. Calls were emitted spontaneously or were induced by an intrahypothalamic-preoptic injection of glutamate. Sonographic analysis of recorded calls revealed that they were within the 35-70-kHz sound frequency range reported for the 50-kHz call type. Systemic amphetamine (AMPH, 2 mg/kg) significantly increased the number of spontaneously emitted 50-kHz calls and the effect of AMPH was dose-dependent. Low dose of intracerebral glutamate (17 microg) had no additive effect on the number of AMPH-induced calls. Higher dose of intracerebral glutamate alone (34 microg) significantly increased the number of 50-kHz calls, which was completely reversed by systemic application of haloperidol (2 mg/kg), a dopamine antagonist. The results suggest that glutamate-induced or spontaneously occurring 50-kHz calls in adult rats are dependent upon dopaminergic transmission. It is postulated that this type of calls may be indicative of dopamine mediated affective state in adult rats.
Wintink
A J
AJ
Department of Psychology, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario, L2S 3A1, Canada.
Brudzynski
S M
SM
D000375:Aging / Q000502:physiology; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000187:drug effects; D004298:Dopamine / Q000008:administration & dosage / Q000502:physiology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D018698:Glutamic Acid / Q000008:administration & dosage / Q000502:physiology*; D006220:Haloperidol / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014465:Ultrasonics; D014828:Vocalization, Animal / Q000187:drug effects* / Q000502:physiology
D018492:Dopamine Antagonists; D018765:Dopamine Uptake Inhibitors; D018698:Glutamic Acid; D000661:Amphetamine; D006220:Haloperidol; D004298:Dopamine