Virtual Lecture by Matthew Larkum: A dendritic mechanism for loss of consciousness
Anesthetics have been used to block consciousness since the very beginning of neuroscience itself. Given the huge implications of their action, this ought to have been amongst the first pharmacological effects to be empirically explained. The great mystery of anesthetics is not so much that they block consciousness per se – many drugs can do this – but that they do this so precisely and reversibly without apparently altering the way most neurons operate. Furthermore, the various chemicals that have anaesthetic action are quite various with multiple molecular targets. It has proved frustratingly difficult to find a unifying explanation and yet it is also assumed that explaining how consciousness is removed would put us one step away from understanding consciousness itself. Here, I present recent data showing that anaesthetics have a remarkable and reliable effect on the coupling of dendritic compartments in cortical pyramidal neurons. This suggests a hypothesis for how anaesthesia works which is consistent with separate data showing that regulation of dendritic compartments in these neurons also modulates conscious perception.