Minimal experience required for immediate-early gene induction in zebra finch neostriatum

We show that a single presentation of a zebra finch song, 2 a in duration, will induce an "immediate-early gene" response in the caudomedial neostriat um of zebra finches (Poephila guttata). Repetition of this stimulus 10 time s is sufficient to induce a maximal increase in RNA and protein, detected 3 0 and 90 min later respectively. Thus very brief stimuli can set in motion a slow genomic process in the brain which takes hours to resolve. Immediate -early gene function is often considered in the context of a "feedback" mod el (i.e.: to consolidate memories of the inducing event). However, based on the long lag observed here between initiation and full expression of the m olecular response, we suggest an alternative, ethologically based, "feed-fo rward" model in which exposure to a novel or significant context triggers a n increase in the efficiency of memory capture processes for subsequent exp eriences, (C) 2000 Academic Press.