Humboldt-Universität zu Berlin

Anesthesia, apical dendrites, and thalamocortical loops

General anesthesia selectively disrupts consciousness by impairing feedback signaling, even when feedforward pathways and basic neuronal function remain largely intact. This talk will explore how anesthesia targets apical dendrites in cortical layer 5 pyramidal neurons, leading to the decoupling of cortico-cortical and thalamo-cortical communication. We demonstrate that various anesthetics consistently block signal propagation along apical dendrites, a key nexus for integrating feedback. Additionally, this decoupling effect can be mimicked by inhibiting metabotropic glutamate and cholinergic receptors or by silencing higher-order thalamic activity. These findings highlight the critical role of apical dendrites in maintaining the thalamocortical loops essential for conscious perception and suggest that disruptions at this nexus underlie the unconscious state induced by anesthesia.

Invited by Luc Estebanez