OPTICAL MONITORING OF MOVEMENTS IN SMALL ANIMALS AND IN SEMIINTACT PREPARATIONS

A system has been developed for monitoring motor patterns both in smal l animals and in semi-intact preparations. Using a video recording sys tem, the optical image of the selected object is projected onto a TV m onitor to which is attached a pair of photosensitive resistors or diod es. The signals from the photosensor are amplified, filtered prior to being recorded, or stored using commercially available data capture sy stems. Use of the paired photosensitive elements allows us to avoid ch anges in background illumination, using a differential amplification f unction, during different patterns of activity of monitored organs or animals and also allows us to record activity from several different o rgans or systems simultaneously. The simplicity of the system enables us to perform simultaneous monitoring of both effector movements and n euronal activity via multi-channel microelectrode recordings. We have tested this system using semi-intact preparations of the freshwater pu lmonate snail, Lymnaea stagnalis. Examples of different types of recor dings are presented.