Extended Data Fig. 5: Transcranial photoactivation of ChRmine enabled functional control of dopaminergic neurons.

DAT-Cre mice with ChRmine-oScarlet expression in dopaminergic neurons were subjected to a real-time place preference test. Percent of time spent on the stimulation side receiving transcranial photostimulation with the following parameters: a, tonic (1 Hz) or phasic (20 Hz) stimulation delivered at 800 mW mm^-2 and 5-ms pulse width; b, with and without stimulation at 40 mW mm^-2 delivered at 5 Hz with 100-ms pulse width (n=5 mice; two-sided paired t-test, P = 0.018 (a); P = 0.023 (b)). c, DAT-Cre mice expressing bReaChES did not exhibit place preference even at irradiance (I) of 3200 mW mm^-2, 500 ms ON/OFF, 20 Hz and 5-ms pulse width (n = 4 mice (bReaChES), n = 6 mice (ChRmine); one-way repeated-measure ANOVA: F(4,12)=1.15, P = 0.38 (bReaChES) and two-sided paired t-test (ChRmine), P = 0.02). d, Representative confocal images of neurons in the VTA expressing red fluorescent protein and/or the indicated opsin (red) stained with DAPI (blue) and cFos (white). Scale bar: 100 µm. e, Percentage of cFos⁺ cells among DAPI-labeled cells in the VTA following 10 minutes of transcranial photostimulation at 20 Hz and 800 mWmm^-2 with 5-ms pulse width. Animals were sacrificed after 90 minutes (n = 4 per group; one-way ANOVA with Bonferroni post hoc tests: F(3,12) = 14.24, P = 0.0003). *P < 0.05; **P < 0.01; NS, not significant. Data are mean ± sem.