Fig. 5: In vivo modulation capabilities of T-DOpE probe: optogenetic and drug infusion.

a Example trace of wideband extracellular response to optical stimulation. b The firing rate of sorted cells during optical stimulation and the normalized firing rate across all sessions. c Examples of optically evoked responses with three levels of laser power. No response was observed in the cortex due to AAV-ChR2 expression localized to CA1. The amount of optically evoked neuron activity can be increased by varying the light output, allowing us to achieve optically induced SPW-Rs at higher laser powers. * shows spontaneous SPW-Rs in between optical stimulations. d Normalized firing rate of sorted cells in saline, vehicle, and drug+vehicle infusion. Note shortly after the infusion, the firing rate of all cells drastically decrease not due to pharmacological influence but to the physical displacement of the cells from the recording sites. e Spike amplitude of an interneuron and a pyramidal cell to demonstrate the recovery after infusion (200 nL; 1 nL s⁻¹). Given the device tip contains both the microfluidic channel and recording sites (<20 µm in distance), the cells are pushed away and return after some period of time. f Average spike waveforms of the two cells before and after infusion. g Autocorrelation of the two cells before and after infusion.