OPTOELECTRONIC MONITORING OF INDIVIDUAL WHISKER MOVEMENTS IN RATS

We describe two systems for the real-time recording and display of ind ividual vibrissa movements in head-fixed rats. Both systems utilize hi gh-speed, linear image sensors, each composed of an array of light sen sitive elements (CCDs). Uniform illumination of the array generates a constant baseline voltage in each element. The shadow produced by the movement of a whisker interposed between the light source and the sens ors produces a voltage shift in a subset of elements. The successive p osition of the shift is linearly related to the momentary whisker posi tion. Associated software/hardware scans the array at regular interval s to identify the successive positions of voltages above a preset thre shold and outputs the data to a microprocessor for computation of the whisker movement trajectory. In both systems, movements of a single wh isker may be monitored 'on-line' with high spatial and temporal resolu tion; in one case with, in the other without the presence of neighbori ng whiskers. Optoelectronic monitoring facilitates rapid and efficient (computer-assisted) acquisition and analysis of data on rodent whiski ng behavior. (C) 1998 Elsevier Science B.V. All rights reserved.