[The effects of actinomycin D on the brain RNA synthesis and on the passive avoidance latency in the goldfish (author's transl)].

(a) Intracranial injection of actinomycin D (2 mug/10 mul/fish) inhibited about 70% of the goldfish brain RNA synthesis from 3 hours to 4 days later. (b) The goldfish injected actinomycin D intracranially was given the passive avoidance training. Intraday-acquisition (short-term memory) was not blocked but interday-retention (long-term memory) was markedly blocked. It might suggest that the brain RNA synthesis is not related to short-term memory but is necessary for long-term memory.