Spindle oscillation in cats: the role of corticothalamic feedback in a thalamically generated rhythm.

作者：Diego Contreras, Mircea Steriade · 发表于：The Journal of Physiology · 年份：1996 · DOI：10.1113/jphysiol.1996.sp021133 · 被引用次数：335 · 研究领域：Neuroscience and Neuropharmacology Research、Sleep and Wakefulness Research、Photoreceptor and optogenetics research

1. Spindles represent an oscillatory activity (7-14 Hz) of the electroencephalogram (EEG) originating in the thalamus and appearing during early stages of sleep. We investigated: (i) the phase relations between thalamic and cortical neurons during this rhythm; (ii) the patterns of spindles under different anaesthetics and their modifications at various levels of the membrane potential (Vm); and (iii) the potentiating role of the corticothalamic feedback in the genesis of spindles. Intra- and extracellular recordings were performed in cats from reticular and dorsal thalamic nuclei, as well as from various cortical areas. 2. In thalamic reticular neurons, spindles were sequences of waves at 7-14 Hz, riding on a prolonged depolarizing plateau and occurring in phase with depth-negative cortical EEG waves. In thalamocortical cells, spindles consisted of inhibitory postsynaptic potentials (IPSPs) in phase with depth-positive cortical EEG waves and occasionally leading to rebound spike bursts. In cortical cells, spindle waves were rhythmic (7-14 Hz) excitatory postsynaptic potentials (EPSPs) that sometimes gave rise to action potentials. Spindles occurred in phase among thalamic reticular, thalamocortical and neocortical neurons. 3. In thalamic reticular neurons, spindle waves and their depolarizing plateaux increased in amplitude with slight cellular hyperpolarization, but at a Vm more negative than -80 or -85 mV they decreased in amplitude. No frequency alterations were observed w...