Effect of alpha-amanitin on brain RNA and protein synthesis and on retention of avoidance conditioning.

The effect of a sublethal dose of alpha-amanitin given intraventricularly to rats on retention of passive and active avoidance conditioning has been studied, together with the effect on brain RNA and protein synthesis in vivo. The toxin brings about a significant impairment of retention of both passive and active conditioning in rats poisoned 6 hr or 24 before training. Brain RNA synthesis is decreased at 6 hr after poisoning, whilst protein synthesis decreases at a later stage (not before 12 hr after poisoning). Thus in rats poisoned with alpha-amanitin memory consolidation is impaired when RNA synthesis is decreased, and before protein synthesis is affected.