Activite operante et locomotrice chez des rats eleves dans des milieux differents

Male and female rats of the inbred August and Fischer strains were reared during two months after weaning either in a standard laboratory environment (controls) or in a more complex environment (treated animals). The performance of these rats was measured afterwards in an operant conditioning situation with positive reinforcement. The multiple reinforcement schedule used included CRF and extinction periods. The treated animals, regardless of their sex or strain, displayed a higher response rate than the controls in both the CRF and extinction periods. This difference, however, appears only after several conditioning sessions and does not seem to be linked with the level of locomotor activity as measured by photocell actographic recording. The implications of the results are discussed.