Relations between cortical and thalamic cellular events during transition from sleep patterns to paroxysmal activity

• DOI: 10.1523/jneurosci.15-01-00623.1995
• Publication Date: 2018-04-02T18:40:37Z
• Authors: M Steriade; D Contreras
• Keywords: Cortical neurons; Tonic (physiology); Hyperpolarization; Neocortex; Reticular connective tissue

We investigated in anesthetized cats the progressive development from EEG-synchronized sleep patterns to low-frequency (< 15 Hz) paroxysmal activities, most of them consisting epileptic-like seizures with spike-wave (SW) complexes at 2-4 Hz. used multisite extra- and intracellular recordings neocortical, reticular thalamic (RE), thalamocortical (TC) neurons, including dual impalements cortical TC cells. A subsample (40%) cells discharged spike bursts Hz, close time relation spiky, depth-negative field components SW related neocortical areas. Full synchronization among that were resonant seizure activity was progressively reached toward end paroxysm. The remaining (60%) inhibited during seizures. show duration amplitude hyperpolarization paralleled extent EEG Dual neurons demonstrate seizure, a tonic depolarization superimposed bursts, simultaneously recorded displayed associated repetitive IPSPs, closely cell bursts. inhibition presumably mediated by GABAergic RE neurons. Indeed, paroxysm showed excitation accompanied corresponding IPSPs emphasize some forms activities. propose inhibitory processes found significant number may contribute loss consciousness, due obliteration synaptic transmission through thalamus.