Quinpirole-induced 50 kHz ultrasonic vocalization in the rat: role of D2 and D3 dopamine receptors.

The goal of the present investigation was to study a full dose-response of quinpirole in production of species-specific 50 kHz ultrasonic vocalizations in rats, and to study involvement of D2 and D3 dopamine receptors in this response. Quinpirole, a D2/D3 dopamine agonist with high selectivity for D2 dopamine receptors, was injected into the shell of the nucleus accumbens. Quinpirole induced species-specific 50 kHz ultrasonic vocalizations at a wide range of doses as compared to saline.

Effects of intraaccumbens amphetamine on production of 50 kHz vocalizations in three lines of selectively bred Long-Evans rats.

Effects of direct injections of amphetamine into the shell of the nucleus accumbens were studied in three lines of Long-Evans rats, two of which had been selected for low and high rates of 50 kHz calls in adolescence in response to a standard social stimulation, and compared to results from randomly selected rats. Injections of amphetamine into the medial shell of the nucleus accumbens significantly increased the number of 50 kHz vocalizations in the high line but not low line, as compared to the random controls. This response was shell specific and antagonized by raclopride.