|
Control of Spatiotemporal Coherence of a Thalamic Oscillation by Corticothalamic Feedback.Diego Contreras, Alain Destexhe, Terrence J. Sejnowski and Mircea SteriadeScience 274: 771-774, 1996. AbstractThe mammalian thalamus is the gateway to the cortex for most sensory modalities. Nearly all thalamic nuclei also receive massive feedback projections from the cortical region to which they project. In this study, the spatiotemporal properties of synchronized thalamic spindle oscillations (7 to 14 hertz) were investigated in barbiturate-anesthetized cats, before and after removal of the cortex. After complete ipsilateral decortication, the long-range synchronization of thalamic spindles in the intact cortex hemisphere changed into disorganized patterns with low spatiotemporal coherence. Local thalamic synchrony was still present, as demonstrated by dual intracellular recordings from nearby neurons. In the cortex, synchrony was insensitive to the disruption of horizontal intracortical connections. These results indicate that the global coherence of thalamic oscillations is determined by corticothalamic projections.MoviesSeveral mpeg movies illustrate the spatiotemporal dynamics of oscillations in the thalamus as recorded by multisite tungsten electrodes. These mpeg movies are animated versions of Fig. 2 of the paper above.thalamus_intact_fast.mpg : Synchronized spindle oscillations in the thalamus with intact cortex (fast time scale) thalamus_intact_slow.mpg : Synchronized spindle oscillations in the thalamus with intact cortex (slow time scale) thalamus_decort_fast.mpg : Disrupted synchrony of spindle oscillations in the thalamus following removal of the cortex (fast time scale) thalamus_decort_slow.mpg : Disrupted synchrony of spindle oscillations in the thalamus following removal of the cortex (slow time scale) |