Fig. 4: In vivo single-neuron activation by targeted photostimulation.

a In large FOVs (~450 × 450 μm²), photostimulation to an individual ensemble neuron did not co-activate other ensemble neurons (P.S. photostimulation; V.S. visual stimuli; n = 5 photostimulation trials from 5 ensembles, 3 mice). b The duration of Ca²⁺ transients evoked by photostimulation and visual stimuli, respectively. p = 5.0 × 10⁻¹⁰; n = 55 neurons; two-tailed paired t test. c Photostimulation to an individual target neuron (neuron 1). Lower: The Ca²⁺ responses of neurons 1 and 2 to CS before and after photostimulation. n = 6 ensembles from 4 mice. Scale bar: 20 μm. d Physiological responses of ensemble neurons were recorded before and after photostimulation targeted at an individual ensemble neuron, as well as in response to visual stimuli. n = 6 ensembles from 4 mice. e The Ca²⁺ amplitude of other neurons in the ensembles to visual stimuli before and after the photostimulation to an individual neuron. n = 15 neurons from 4 mice; Two-tailed Mann-Whitney test. f Physiological responses of individual neurons from different ensembles to targeted photostimulation and visual stimuli, respectively. n = 19 neurons from 6 mice. g Quantified Ca²⁺ amplitude of the neurons to visual stimuli before and after photostimulation. n = 19 neurons from 6 mice; Two-tailed Wilcoxon matched-pairs signed rank test. h Continuous neuronal activity was recorded over an extended period before and after photostimulation. The frequency of spontaneous Ca²⁺ signals before and after photostimulation were calculated, respectively (n = 7 photostimulation trials from 7 neurons, across 3 mice; Wilcoxon matched-pairs signed rank test). i The neuronal responses to the US after several photostimulations at different powers. Right: The Ca²⁺ amplitude of neuronal responses to the US before and after multiple photostimulations, respectively (n = 11 neurons from 6 mice; Two-tailed Wilcoxon matched-pairs signed rank test). Scale bar: 10 μm. n.s., no significant difference. Error bars for the averaged plot indicate mean ± s.e.m. Source data are provided as a Source Data file.