A computerized system for the simultaneous monitoring of place conditioning and locomotor activity in rats

Place conditioning is one of the most popular behavioral methods for assessing the rewarding properties of various substances. Many substances that are rewarding also influence motor activity. This report describes a computerized system designed to simultaneously monitor both place conditioning and locomotor activity. The system consists of 4 independent conditioning boxes, each equipped with 6 pairs of photosensors connected to an Experiment Controller, an electronic board containing a microprocessor, a programable timer, and 16 K of RAM used to store both instructions and data. The effects of the stimulant (+) - amphetamine were assessed using this system and found to produce a place preference comparable to that obtained from a previously utilized mechanical timer system. The computerized system also demonstrated that amphetamine increased unconditioned activity. There are a number of advantages and broader applications of the new methodology.