Aj. Wintink et Sm. Brudzynski, The related roles of dopamine and glutamate in the initiation of 50-kHz ultrasonic calls in adult rats, PHARM BIO B, 70(2-3), 2001, pp. 317-323
Effects of amphetamine on the production of 50-kHz ultrasonic calls were st
udied. Calls were emitted spontaneously or were induced by an intrahypothal
amic-preoptic injection of glutamate. Sonographic analysis of recorded call
s revealed that they were within the 35-70-kHz sound frequency range report
ed for the 50-kHz call type. Systemic amphetamine (AMPH, 2 mg/kg) significa
ntly increased the number of spontaneously emitted 50-kHz calls and the eff
ect of AMPH was dose-dependent. Low dose of intracerebral glutamate (17 mug
) had no additive effect on the number of AMPH-induced calls. Higher dose o
f intracerebral glutamate alone (34 mug) 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 glut
amate-induced or spontaneously occurring 50-kHz calls in adult rats are dep
endent upon dopaminergic transmission. It is postulated that this type of c
alls may be indicative of dopamine mediated affective state in adult rats.
(C) 2001 Elsevier Science Inc. All rights reserved.