Chronic cocaine pretreatment facilitates Pavlovian sexual conditioning in male Japanese quail.

Repeated drug exposure that results in behavioral sensitization has been shown to enhance sex-seeking behaviors in rats as well as facilitate Pavlovian excitatory and inhibitory conditioning. In the present experiment, male Japanese quail were given repeated presentations of cocaine (10 mg/kg, i.p.) that resulted in increased locomotor activity relative to saline. After a 10-day withdrawal period, subjects received sexual conditioning trials that consisted of presentation of an object conditioned stimulus (CS) followed by sexual reinforcement. Results showed that birds that previously received chronic cocaine demonstrated more conditioned approach behavior to the CS object, a shorter latency to copulate with a female, and made more cloacal contacts (copulatory behavior) during sexual reinforcement than saline-treated birds. The findings suggest that chronic cocaine later facilitates Pavlovian conditioning in a sexual behavior paradigm. This may be the result of cocaine facilitating learning via the dopaminergic system. The findings are discussed in the context of the incentive sensitization theory and possible neuronal mechanisms.