Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Mean (SE) locomotor response (number of beam breaks in an electronic array per 90 min) to 1 mg/kg d-amphetamine (i.p.) on 5 weekly sessions in groups of Sprague Dawley rats (n = 8/ group) previously exposed to 15 daily conditioning sessions with sucrose reward (10% solution) delivered under 0, 25, 50, 75, or 100% variable schedules. The conditioned stimulus was a light (120 s). Group 0 received the same number of rewards as group 100 in the absence of conditioned stimuli.
