Development of 24 hour retention of escape learning in neonatal C3H mice

✍ Scribed by Z. Michael Nagy; James R. Misanin; Peter L. Olsen

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 525 KB
• Volume: 5
• Category: Article
• ISSN: 0012-1630
• DOI: 10.1002/dev.420050310

✦ Synopsis

The development of 24-hr memory of an escape response in neonatal C3H mice was examined in 2 experiments. In experiment 1, separate groups of mice received 25 trials of escape training for 3 consecutive days (24 hour Inter-session-interval) beginning at 5, 7, and 9 days of age. Several different measures demonstrated within-session improvement for all ages on all test days. However, between-session improvement which was not due to maturation did not occur until after 9 days of age. In experiment 2, separate groups of mice received 25 escape training trials at either 8 or 10 days of age, and were retested 24 hrs later. Comparisons of the retest scores with original training scores as well as with littermate controls without prior training experience, showed that 8-day old mice failed to show retention effects of prior training, whereas 10-day old mice performed better on the retention test than they had on original training, as well as better than controls without previous training. The results suggest that 24-hr memory of the escape task develops at 9-10 days of age in the C3H mouse.

The ability of neonatal rodents to show improved performance in a relatively simple escape task has recently been reported for mice (Nagy, Misanin, & Newman, 1970; Nagy, Misanin, & Olsen, 197 1) and rats (Misanin, Nagy, & Weiss, 1970) as young as 5 days of age. Several measures of performance suggested improved escape behavior by the end of the training session for both species. However, although the 5-day old rat appears to show within-session learning, the ability to retain the improved performance level for a 24-hr period does not occur until 9 days of age Wisanin, Nagy,