A novel computerized system for analyzing motor and social behavior in groups of animals

We present here the VMB Tracking System, a novel method for tracking locomo tor activity, posture, thigmotactic scanning behavior and social interactio ns of up to eight animals at a time, at a high resolution (up to +/- 0.1 mm ). We used a commercially available computerized system that is considerabl y cheaper than other available methods. This system utilizes a basic person al computer controlling three transponders ('towers') fixed in space above the tested area, where animals as small as rats stroll freely in their norm al habitat or in an experimental arena. Each tower emits infra-red OR) puls es to a transponder ('button') adhered to a plastic mount glued to a shaved area of-skin on the animal's back. When the button detects the IR pulses i t responds with a button-specific ultrasonic signal that is fed back to the towers. The 3D location of the buttons is calculated by triangulation. Mov ement parameters of each button, such as displacement trajectory, time, spe ed and acceleration, can be displayed on-line and stored for off-line analy sis. This system can be used to track animals in any lighting conditions, a nd to assess drug effects on the CNS, neuromuscular junction or muscle. As an example we demonstrate the ataxic effects of pentobarbital in rats. (C) 1998 Elsevier Science B.V. All rights reserved.