THE MIRROR CHAMBER TEST FOR TESTING ANXIOLYTICS - IS THERE A MIRROR-INDUCED STIMULATION

A new murine model of anxiety, namely the mirror chamber test, is base d on the assumption that, like many species, mice show approach-avoida nce behavior when they are confronted by a minor. It has been suggeste d that the mirror chamber is a specific and a quantitatively/qualitati vely different measure of anxiety than that implicated in other behavi oral models such as the elevated plus-maze and the head-dipping assays . The aim of the present study was to investigate whether there was in deed a specific mirror effect by replacing the mirrors in the chamber by either white or dark-gray tiles. Balb/c, DBA-derived, and C57 BL/6j mice were tested under these three experimental conditions. The resul ts indicated that Balb/c and DBA-derived mice avoided the mirror, whit e and gray chambers similarly while C57 BL/6j mice entered more readil y and spent more time in the gray chamber than in the mirrored or whit e chambers. Thus, depending on the strain of mouse studied, a brightne ss or a position effect in the chamber could explain the avoidance beh avior observed. These results suggest that there is no need to invoke a specific minor effect. (C) 1998 Elsevier Science Inc.