Infant Handling: Effects on Avoidance Learning, Brain Weight, and Cholinesterase Activity

See allHide authors and affiliations

Science  03 May 1963:
Vol. 140, Issue 3566, pp. 486-487
DOI: 10.1126/science.140.3566.486


Infant rats were "handled" by removing them periodically from their home cages. "Non-handled" rats were left undisturbed. Half of the animals were killed at weaning, and weights and cholinesterase activity were determined on four different sections of the brain. The remaining animals were conditioned to avoid an administered shock. Handling increased ventral-cortex and subcortical weights and decreased subcortical cholinesterase. No differences in avoidance conditioning were observed.