Affiliation:
1. Laboratoire de Neurophysiologie, Faculté de Médecine, Université Laval, Quebec G1K 7P4, Canada
Abstract
Contreras, Diego, Alain Destexhe, and Mircea Steriade. Intracellular and computational characterization of the intracortical inhibitory control of synchronized thalamic inputs in vivo. J. Neurophysiol. 78: 335–350, 1997. We investigated the presence and role of local inhibitory cortical control over synchronized thalamic inputs during spindle oscillations (7–14 Hz) by combining intracellular recordings of pyramidal cells in barbiturate-anesthetized cats and computational models. The recordings showed that 1) similar excitatory postsynaptic potential (EPSP)/inhibitory postsynaptic potential (IPSP) sequences occurred either during spindles or following thalamic stimulation; 2) reversed IPSPs with chloride-filled pipettes transformed spindle-related EPSP/IPSP sequences into robust bursts with spike inactivation, resembling paroxysmal depolarizing shifts during seizures; and 3) dual simultaneous impalements showed that inhibition associated with synchronized thalamic inputs is local. Computational models were based on reconstructed pyramidal cells constrained by recordings from the same cells. These models showed that the transformation of EPSP/IPSP sequences into fully developed spike bursts critically needs a relatively high density of inhibitory currents in the soma and proximal dendrites. In addition, models predict significant Ca2+ transients in dendrites due to synchronized thalamic inputs. We conclude that synchronized thalamic inputs are subject to strong inhibitory control within the cortex and propose that 1) local impairment of inhibition contributes to the transformation of spindles into spike-wave-type discharges, and 2) spindle-related inputs trigger Ca2+ events in cortical dendrites that may subserve plasticity phenomena during sleep.
Publisher
American Physiological Society
Subject
Physiology,General Neuroscience
Cited by
134 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献