NT-3 facilitates hippocampal plasticity and learning and memory by regulating neurogenesis (original) (raw)

  1. Kazuhiro Shimazu1,
  2. Mingrui Zhao1,
  3. Kazuko Sakata1,
  4. Schahram Akbarian2,3,
  5. Brian Bates2,4,
  6. Rudolf Jaenisch2, and
  7. Bai Lu1,5
  8. 1 Section on Neural Development and Plasticity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA;
  9. 2 Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA

Abstract

In the adult brain, the expression of NT-3 is largely confined to the hippocampal dentate gyrus (DG), an area exhibiting significant neurogenesis. Using a conditional mutant line in which the NT-3 gene is deleted in the brain, we investigated the role of NT-3 in adult neurogenesis, hippocampal plasticity, and memory. Bromodeoxyuridine (BrdU)-labeling experiments demonstrated that differentiation, rather than proliferation, of the neuronal precursor cells (NPCs) was significantly impaired in DG lacking NT-3. Triple labeling for BrdU, the neuronal marker NeuN, and the glial marker GFAP indicated that NT-3 affects the number of newly differentiated neurons, but not glia, in DG. Field recordings revealed a selective impairment in long-term potentiation (LTP) in the lateral, but not medial perforant path-granule neuron synapses. In parallel, the NT-3 mutant mice exhibited deficits in spatial memory tasks. In addition to identifying a novel role for NT-3 in adult NPC differentiation in vivo, our study provides a potential link between neurogenesis, dentate LTP, and spatial memory.

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