ONTOGENY OF ACTIVE-AVOIDANCE IN THE RAT - LEARNING AND MEMORY

Ontogenetic development of active avoidance learning, extinction and retention was studied in rats. The learning of a 1-way active avoidance was most rapid between wk 4 and 6, although some slight gender-related differences were evident. No such unambiguous development was detected in forced extinction. The 24-h retention of avoidance peaked at the age of 4 wk while 1-mo. retention was best in animals trained at the age of 8 wk. The retrieval of memory trace also had best values at these ages. Retention of forced extinction peaked in 6-wk animals. The existence of developmental critical periods must be considered cautiously as various functions have different time courses depending upon the chosen parameters in assessment.