Slide 6

Whole cell recording from a layer 5 pyramidal cell in the auditory cortex reveals that the membrane potential of these cells closely follows the state of the mouse, as revealed by pupil diameter. During periods of rest (not walking), the arousal state of the animal exhibits "microarousals" associated with brief dilation of the pupil, depolarization of the neuron, and suppression of low frequency rhythms. Walking is preceded by membrane potential depolarization and dilation of the pupil. These results reveal a remarkable association between arousal level and membrane potential of some cortical pyramidal cells.