opto-5: Immediate tDCS effect on LFPs & SEPs

Experiment: Immediate effects of anodal and cathodal tDCS on local field potentials (LFPs) produced by photostimulation of glutamatergic or GABAergic neurons and whiskers sensory-evoked potentials (SEPs). Description: This experiment was designed to assess the immediate effects of transcranial direct current stimulation (tDCS) on cortical responses to sensory and optogenetic input in the primary somatosensory cortex (S1). Both anodal and cathodal short pulses of tDCS were applied at randomized intensities (±50, ±100, ±150, ±200 μA), each consisting of a 5 s ramp-up, 5 s steady-state, and 5 s ramp-down phase, followed by 10 s without stimulation. In total, 15 pulses per intensity and polarity were delivered, for a total duration of approximately 3000 seconds. During each trial, an electrical stimulus was delivered to the whisker pad, followed 2 seconds later by a light pulse in S1. This stimulation sequence was used across all conditions (control, anodal, and cathodal tDCS). In the control condition, the whisker stimulus occurred at second 5 and the light pulse at second 7. During tDCS trials, the same stimuli occurred earlier, at second 3 and second 5, respectively, to allow recording of evoked responses during the plateau phase of the tDCS pulse. This protocol enabled simultaneous investigation of how tDCS acutely modulates LFPs and whisker-evoked SEPs, as well as optogenetically evoked responses, across a range of intensities and polarities. Access before the embargo ends: the files are under embargo until 30 June 2027. To request access before then, email Ricardo Salvador ([e-mail]) with a short description of the intended use.