Branching fiberoptic patchcord

The setup and parameters for in vivo optogenetics were similar as described previously^{40 (link), 43} . A 473 nm blue laser (Shanghai Laser & Optics), TTL-controlled by a pulse-generator (Master-8, A.M.P.I., or DG1022, Rigol), was coupled to a branching fiberoptic patchcord (Doric Lenses) through a fiber optic rotary joint (Prizmatix). Light intensity at the exit of each branch was adjusted to ~6 mW, which reached ~5 mW at the exit of the fiberoptic implants (~80% transmission). Bilateral fiberoptic implants delivered trains of light pulses (1 ms pulses at 10 Hz, 5 sec on 5 sec off) selectively during sleep. Closed-loop stimulation system was modified from a previously described system⁹ . Real-time sleep scoring was performed using SleepMaster program (Biosoft Studio, Hershey, PA), and based on weighted considerations of EEG amplitude, EMG amplitude, delta power (0.5–4 Hz), theta power (4.5–8 Hz), beta power (30–50 Hz), and EEG variation (SD/Mean). Correct stim: ≥ 3 secs of stimulation in a 10-sec NREM or REM epoch; correct non-stim: ≤ 3 secs of stimulation within a 10-sec Wake epoch; false stim: > 3 secs of stimulation in Wake epochs; false non-stim: < 3 secs of stimulation during sleep epochs. For additional within-subject controls, rats received handling and patchcord attachment during baseline without getting laser stimulation.