Input processing by adult-born dentate granule cells

M BELEN PARDI; LUCAS A MONGIAT; ALEJANDRO F SCHINDER; ANTONIA MARIN BURGIN

New Orleans

Congreso; Society for Neurosciences Annual Meeting; 2012

Society for Neurosciences

The dentate gyrus of the adult hippocampus continuously generates new granule cells (GCs). The addition ofa constant pool of new GCs to the dentate gyrus has been proposed to be a source of hippocampal neuralplasticity. These neurons integrate into the circuit as they develop their intrinsic properties and afferentconnectivity until they reach their maturity after 8 weeks approximately.It has recently been shown that 4 week-old immature GCs (4 wpi) exhibit higher excitability and LTP levels.However the functional contributions of these neurons to the hippocampal function are little known.We focused this work on three aspects related to adult-born GCs functional role:1) Differences in the recruitment of immature adult-born and mature GCs in response to stimulation of afferent inputs. 2) The influence of inhibitory circuits in the population of immature vs mature GCs. 3) The degree of specificity/input integration of the population of immature and mature GCs in the representation of independent inputs. By combining retroviral labeling, calcium imaging and electrophysiology we show a differential role of mature and immature GC populations in processing information arriving to the dentate gyrus of the hippocampus