Response of a brain protein fraction 24 hours after training in rats.

The aim of the study was to follow the amount and incorporation of 14C-valine into separate, soluble protein fractions of the hippocampus, thalamus, and visual cortex of rats from 0 to 72 hr after training. The behavioral test consisted of reversal of handedness with training twice daily for 25 min for 2 days, followed by a 5-day intermission without training, and a final session of 24 min. The animals were injected intraperitoneally with 14C-valine 30 min before sacrifice and taken 0, 24, 48, and 72 hr after last training. After 24 hr, and only at that time, double incorporation values and increased amounts were observed in a protein fraction, No. 6 from the front, in all three brain areas of the trained rats compared to active controls. At 48 hr this protein fraction was at control level.