The line graphs on the right side of the figure show the effects of various doses of haloperidol on locomotor activity induced by systemic injections of amphetamine or intracranial injections of muscimol, baclofen, DPDPE, DAMGO or pBB-PZDA, See text for statistical details. The bar graphs on the left of the figure display locomotor activity under the control condition in which animals received systemic injections of saline followed by intracranial, or systemic, injections of saline. Bars are displayed in the same order as listed on the key, and subjects who did not receive cannula implants (i.e., those in the systemic amphetamine group) were less active than animals in the cannulated groups following saline injections.