A role for adult neurogenesis in response to ambiguous cues of threat

Thursday, October 11, 2012 — Poster Session IV
2:00 p.m. – 4:00 p.m.	Natcher Conference Center, Building 45	NIMH	NEURO/BEHAV/SENSYS-6

Authors

• L.R. Glover
• H.A. Cameron
• D.M. Bannerman

Abstract

The rodent hippocampus is involved in aspects of anxiety. Within the hippocampus, the dentate gyrus produces new neurons throughout life, termed adult neurogenesis. Studies have shown that an animal’s stress response, manifesting as depressive- and/or anxiety-like behaviors, is influenced by these new neurons and the efficacy of anxiolytics is dependent upon them. Here, we conditioned one group of mice (“perfect predictor”) to a cue that always predicts an aversive event (shock) and another group (“imperfect predictor”) where the cue only signals shock half of the time, creating an ambiguity about threat (anxiety). Mice that lack adult neurogenesis and normal controls were compared in both conditions. In the perfect predictor group, we find that mice that lack adult neurogenesis are indistinguishable from controls, as measured by freezing behavior. In the imperfect predictor group, however, we find that controls freeze more to the conditioned cue than those mice that lack new neurons being born. Ongoing studies are being conducted to determine if this deficit in freezing behavior is the result of failure in associative learning or if this difference is attributable to a change in the perception or behavioral expression of anxiety.

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