Automated TV-based system for open field studies: effects of methamphetamine.

A method is described whereby open field behaviour of rats can be automatically registered using a TV camera, a video converter, an X-Y recorder and a papertape puncher. Use is made of the scanning properties of the TV camera to obtain the X and Y coordinates of the rat's position and to print this position on an X-Y recorder to obtain the running pattern. In addition, the X and Y coordinates at 1 sec intervals are punched on papertape. With computer processing of the tape, one can obtain--for any given period--the distance run, a frequency distribution of speeds, the number of entries into an inner field, the time spent in an inner field as well as the number of changes in corner positions. As an example the effects of 1 and 2 mg/kg methamphetamine are shown. This drug enhances all parameters measured in a dose-dependent fashion except the changes in corner positions which were not altered significantly.