Inhibitory gating in the Dentate Gyrus

Abstract

-Electrophysiological recordings have demonstrated the existence of a tight inhibitory control of hilar interneurons over Dentate Gyrus granule cells (DGgc). -Our experiments show that LTP induced in the perforant pathway (PP) potentiates glutamatergic synapses and reduces feed-foward inhibition in the DG. -To investigate this phenomenon we implemented a model that includes entorhinal cortex (EC) neurons, DGgc, mossy cells, basket cells and Hil cells. -Our results show that the increase of the glutamatergic inputs results in a net inhibition of the basket cell population. -Results of the model are supported by experiments in vitro where the LTP has been performed in vivo, obtaining this effect in the slice without antagonist GABAa. -Our findings suggest that LTP applied at the EC outputs modifies the excitation/inhibition balance in the Dentate Gyrus facilitating communication with CA3.