A reexamination of apomorphine induced stereotypy in the rat in light of self administration experiments.

1. Apomorphine is known to both elicit stereotypy and to support behavioral self administration. The present report examined a possible contribution of stereotypy to self administration. 2. Non-contingent intraperitoneal injection of apomorphine in adult male Sprague-Dawley rats immediately prior to their placement in an experimental chamber significantly elevated barpressing above operant rates. 3. This indicates a novel dopamine induced behavior which may play a role in determining self administration behavior. 4. The data suggest three interpretations of previous self administration experiments.