Figure 4.

Slow wave sleep delta EEG activity seen in frontal cortex was associated with a classic sleep posture and with isoflurane-induced loss of righting in rats. The isoflurane-induced recordings were clearly lacking some high frequency components, but overall amplitude increases and background frequencies were similar. Chaotic attractors were markedly different for these two signals, however, indicating that circuit level differences were associated with these two brain states. Each attractor plots the data for the accompanying EEG recording. Calibration = 300 μV and 1.0 s.