Fig. 2.

Long-term transduction of Locus Coeruleus with ChR2 allows repeated awakenings from sleep. (A) Schematic of EEG recording from a transduced animal showing implanted optic fiber and EEG/LFP recording from cortex. (B) Opto-activation of the LC (5 Hz, 100 ms pulses for 30 s) reliably produced time locked arousal from sleep showing a loss of EEG spindles (band 10–16 Hz) and also loss of delta power (band 0.4–4 Hz). In contrast sham stimulation (without light) produced no effect. (C) Arousal from sleep was first seen at 4 weeks post transduction and continued to be evoked with the same stimulus parameters (5 Hz, 5 s) until 140 days (post-hoc histology shown in Fig. 1B).