Stimulus and response factors affecting the development of behavioral sensitization to apomorphine.

The present study was designed to assess the role of stimulus and response factors in the context-dependency of behavioral sensitization to the direct dopamine agonist apomorphine. In two experiments, male Wistar rats were given repeated injections of the direct dopamine agonist, apomorphine (5 mg/kg, s.c.

Conditioning and experiential factors affecting the development of sensitization to apomorphine.

In 3 experiments, the role of conditioning and experiential factors in producing behavioral sensitization to apomorphine (APO) was examined. In each experiment, male rats received intermittent injections of APO (5.0 mg/kg s.

Locomotor activity and stereotypy in rats following repeated apomorphine treatments at 1-, 3-, or 7-day intervals.

In two experiments, the effects of repeated intermittent administration of a relatively high dose of apomorphine (5 mg/kg) on locomotor activity and/or stereotypic behavior in rats was determined. In Experiment 1, male rats were given ten subcutaneous (SC) injections of apomorphine or vehicle and tested for locomotor activity and stereotypy. The first nine injection test sessions were given at 3-day intervals and the tenth injection test session was given 18 days following the ninth session.

Latent sensitization to apomorphine following repeated low doses.

In two experiments, the effect of repeated injections of apomorphine on locomotor activity of rats was determined. In each experiment, different groups of rats were injected with either apomorphine (0.2, 1.

Apomorphine-induced aggression: an evaluation of possible sensitizing factors in the rat.

The effects of prior experience with fighting and prior experience with both apomorphine and fighting were evaluated as possible sensitizing factors in rat intraspecific aggression induced by apomorphine. Results revealed that prior experience with the drug alone, or with fighting alone, had no effect on apomorphine-induced aggression. However, animals that had previously fought under the influence of apomorphine showed even higher levels of aggression suggesting that repeated experience with both the drug and fighting induces a type of sensitization.