Transient expression of c-Fos in rat amygdala during training is required for encoding conditioned taste aversion memory.

Local microinjection into rat amygdala of phosphorothioate modified oligodeoxynucleotides (ODNs) antisense to c-fos several hours before conditioned taste aversion (CTA) training impaired taste aversion memory tested 3-5 days after conditioning. In contrast, injection of the antisense ODNs several days before training, before testing, or into the basal ganglia, or injection of c-fos sense ODNs, had no effect on CTA memory. Inhibition of translation by local microinjection of anisomycin into the amygdala shortly before as well as during CTA training, but not several days before training or shortly before testing, also impaired CTA memory. We conclude that translation in general, and c-Fos translation in particular, in the amygdala during or immediately after CTA training is essential for encoding taste aversion memory.