INTERNEURONS AND INHIBITION IN THE DENTATE GYRUS OF THE RAT IN VIVO

摘要: Inhibitory cells are critically involved in shaping normal hippocampal function and thought to be important elements the development of pathologies. However, there is relatively little information about extent pattern axonal arborization interneurons and, therefore, sphere influence these cells. What we do know based largely on vitro slice studies, which interneuronal interactions may severely attenuated. The present study was carried out provide a more realistic picture interneuron influence. Intracellular recordings were obtained from dentate intact brain anesthetized rats, intracellularly labeled with biocytin. arbors two classes traced through hippocampus; each found extend long distances (up half total septotemporal length hippocampus) perpendicular lamellae target preferential strata. These results suggest that have far-reaching effects distant lamellae. One implication this finding neurons should receive inhibitory synaptic drive vivo than preparations, many axon collaterals amputated. Synaptic responses perforant path stimulation examined granule cells, mossy CA3 pyramidal vivo, for comparison previously published studies. In all cell types showed excitatory brief limited by robust IPSPs larger amplitude conductance comparable stimuli recorded vitro. This difference could not explained change intrinsic physiological properties preparation, because those parameters similar We conclude gyrus can affect excitability areas hippocampus, influences cannot appreciated conventional preparations.