Thalamus Modulates Consciousness via Layer-Specific Control of Cortex.
Functional MRI and electrophysiology studies suggest that consciousness depends on large-scale thalamocortical and corticocortical interactions. However, it is unclear how neurons in different cortical layers and circuits contribute. We simultaneously recorded from central lateral thalamus (CL) and across layers of the frontoparietal cortex in awake, sleeping, and anesthetized macaques. We found that neurons in thalamus and deep cortical layers are most sensitive to changes in consciousness level, consistent across different anesthetic agents and sleep. Deep-layer activity is sustained by interactions with CL. Consciousness also depends on deep-layer neurons providing feedback to superficial layers (not to deep layers), suggesting that long-range feedback and intracolumnar signaling are important. To show causality, we stimulated CL in anesthetized macaques and effectively restored arousal and wake-like neural processing. This effect was location and frequency specific. Our findings suggest layer-specific thalamocortical correlates of consciousness and inform how targeted deep brain stimulation can alleviate disorders of consciousness.
['Redinbaugh|Michelle J|MJ|', 'Phillips|Jessica M|JM|', 'Kambi|Niranjan A|NA|', 'Mohanta|Sounak|S|', 'Andryk|Samantha|S|', 'Dooley|Gaven L|GL|', 'Afrasiabi|Mohsen|M|', 'Raz|Aeyal|A|', 'Saalmann|Yuri B|YB|']
D000768:Anesthesia, General D018685:Anesthetics, Inhalation D018686:Anesthetics, Intravenous D000818:Animals D002540:Cerebral Cortex D003243:Consciousness D004558:Electric Stimulation D004569:Electroencephalography D005246:Feedback D005625:Frontal Lobe D020646:Intralaminar Thalamic Nuclei D007530:Isoflurane D008251:Macaca D009434:Neural Pathways D010296:Parietal Lobe D015742:Propofol D012890:Sleep D014851:Wakefulness
consciousness sleep feedback deep brain stimulation anesthesia central thalamus feedforward frontal cortex oscillations parietal cortex