Fig. 7: Optogenetic activation of neurons in the awake marmoset.

a Example traces of band-pass-filtered data during optogenetic stimulation with an 80 Hz sinusoidal pattern of 250 ms duration (25 mW peak). b Trial-averaged, z-scored MUA of all recording sites from an example shank for the 505 nm stimulation condition. Asterisks on the left indicate significant modulation (P < 0.05, two-sided Kolmogorov–Smirnov test for channels with MUA > 3σ) between pre-stimulation baseline window (−25 to 0 ms) and the stimulus window (0 to 25 ms after laser onset; the stimulus window was chosen to be short in order to exclude responses to visual stimuli present in some trials). c Average MUA ± SEM across all significantly modulated channels (n = 32 out of 32 channels), for stimulation with 505 nm and 594 nm, respectively as indicated by the color legend. Note that the 594 nm condition included a subset of trials with visual stimulation, which explains the transiently enhanced MUA around 70 ms post laser onset. d–g Four examples of optogenetically modulated single units: d, e from Monkey A, f and g from Monkey D (the latter receiving 200-ms-long optogenetic stimulation). The left side of each column shows the mean waveform across all 32 recording sites of the relevant electrode shank. Top row: raster plot of spikes around the time of stimulation with 505 nm. Average laser waveform across all trials is shown on top. Second row: trial-averaged and smoothed (Gaussian window, σ = 2 ms) peristimulus time histogram (PSTH) for stimulation conditions with 505 nm and control trials (594 nm or no laser). Shaded area indicates SEM. Third row: peak-normalized auto-correlogram for all detected spikes during the recording session. Note the clear optogenetically induced rhythmicity in the autocorrelations of neurons in (d, e). Bottom row: smoothed firing rate (Gaussian window, σ = 2 s) across the entire session, indicating stability of the recordings. The first and last 5 s of data were excluded due to artifacts arising from the connection or disconnection of the recording system. Source data are provided as a Source Data file.