ANALYSIS OF BEHAVIORAL AND HIPPOCAMPAL VARIATION IN CONGENIC ALBINO AND PIGMENTED BALB MICE

Mice of the BALB/c strain are widely used in behavioral research in sp ite of the albino condition, which can obscure brain-behavior relation ships. We have developed a pigmented BALB strain, congenic to BALB/c, which could be more appropriate for neurogenetic studies that aim at i dentifying the effects of neurological mutations on behavior. Comparis on of inbred albino and pigmented congenic BALB arising from the same litters provides a valuable tool for detecting the consequences of the albino mutation on behavioral performances. Preliminary results prese nted here show that the albino condition does not interfere with the d evelopment and patterns of connectivity of mossy fibers in the hippoca mpus. On the other hand, obvious coat color-linked differences appear for locomotor activity and defecation scores in the open field, pigmen ted mice being unexpectedly less active and more reactive than albino, as if better vision increased their reactions to a novel, anxiogenic environment. Finally, pigmented mice do not show better performances i n the radial maze, which confirms that the inability of BALB mice for spatial learning in a highly demanding version of this task cannot be attributed to their inability to process visual information.