Time windows for effects of protein synthesis inhibitors on Pavlovian conditioning in Hermissenda: behavioral aspects.

Inhibitors of protein and mRNA syntheses inhibit long-term memory (LTM), but we lack information about the time windows during which those inhibitors are effective. Anisomycin (a protein synthesis translation inhibitor) was given to Hermissenda crassicornis which had received sufficient Pavlovian conditioning to produce LTM. When tested after 90 min, LTM recall was blocked when anisomycin was administered until 13 min after conditioning and from 65 to 75 min. There was good recall from 16 to 60 min. When tested at 240 min, two periods of sensitivity to anisomycin were revealed: one finished before 20 min, while the other lasted from 60 to 220 min.A brief study of the transcription inhibitor actinomycin-D found its action similar to that of anisomycin, except not inhibiting recall from about 160 to 220 min.