Behavioral state affects the spike-count autocorrelation function.

Traces indicate the average temporal autocorrelation for spike count fluctuations in alert (blue) and anesthetized (orange) conditions. To calculate autocorrelation, spikes are binned in 2 ms windows and smoothed over a running average of 5 bins. Autocorrelation is normalized by variance and averaged over the population. The time course of autocorrelation is longer under anesthesia, decaying with an exponential time constant of 88 ms compared to 29 ms in the alert state.