Propofol Anesthesia Concentration Rather Than Abrupt Behavioral Unresponsiveness Linearly Degrades Responses in the Rat Primary Auditory Cortex

Loss of consciousness happens abruptly, but does the neuronal activity in our brains also change suddenly? Here we gradually deepen anaesthesia in rats whilst playing aounds and recording how their neurons fire in the auditory cortex. We found a range of different changes with anaesthesia, but all of them changed gradually with increased anaesthesia, and none changed suddenly with loss of consciousness.