PMC

Images show the SED before photoactivation, during photoactivation at 830 nm and after photoactivation to indicate the labeled population.

Role of DA receptor subtypes in SNc-mediated gating of self-grooming. (A) Timeline of mutual occluding experiments in SNc–VMS and SNc–lOFC circuits at D22. (B) Blocking D1R occludes the effect of photoinhibition of SNc–VMS projections on self-grooming time. D1R antagonist SCH23390 (SCH) (0.05 mg/kg body weight) was applied through intraperitoneal injection (saline: n = 6 mice, photoinhibition: 7.833 ± 1.493, drug: 20.17 ± 1.682, photoinhibition plus drug: 8.5 ± 1.176; SCH: n = 6 mice, photoinhibition: 10.17 ± 3.563, drug: 10.67 ± 2.06, photoinhibition plus drug: 10.67 ± 2.525; drug: saline vs. SCH, RM two-way ANOVA with Bonferroni’s test, P = 0.0216; photoinhibition plus drug: saline vs. SCH, RM two-way ANOVA with Bonferroni’s test, P > 0.9999; SCH: photoinhibition vs. photoinhibition plus drug, RM two-way ANOVA with Tukey’s test, P = 0.9941; SCH: drug vs. photoinhibition plus drug, RM two-way ANOVA with Tukey’s test, P > 0.9999). (C) Local application of D1R antagonist SCH (150 nL) in VMS (Left) occludes the effect of photoinhibition of SNc–VMS projections on self-grooming time (saline: n = 4 mice, photoinhibition: 8.75 ± 1.75, drug: 21 ± 1.78, photoinhibition plus drug: 10.5 ± 1.443; SCH: n = 4 mice, photoinhibition: 12.5 ± 1.893, drug: 10.5 ± 1.443, photoinhibition plus drug: 12.75 ± 2.136; drug: saline vs. SCH, RM two-way ANOVA with Bonferroni’s test, P = 0.0167; photoinhibition plus drug: saline vs. SCH, RM two-way ANOVA with Bonferroni’s test, P > 0.9999; SCH: photoinhibition vs. photoinhibition plus drug, RM two-way ANOVA with Tukey’s test, P = 0.997; SCH: drug vs. photoinhibition plus drug, RM two-way ANOVA with Tukey’s test, P = 0.1606). (D and E) Same as B and C, except mutual occluding experiments were performed on SNc–lOFC projections. Intraperitoneal (0.1 mg/kg body weight; (D); saline: n = 6 mice, photoactivation: 9.833 ± 1.579, drug: 18.83 ± 1.74, photoactivation plus drug: 9 ± 1.155; Halo: n = 6 mice, photoactivation: 10.17 ± 2.372, drug: 8 ± 0.7303, photoactivation plus drug: 9.5 ± 1.478; drug: saline vs. Halo, RM two-way ANOVA with Bonferroni’s test, P = 0.0033; photoactivation plus drug: saline vs. Halo, RM two-way ANOVA with Bonferroni’s test, P > 0.9999; Halo: photoactivation on vs. photoactivation plus drug, RM two-way ANOVA with Tukey’s test, P = 0.9333; Halo: drug vs. photoactivation plus drug, RM two-way ANOVA with Tukey’s test, P = 0.579) or local application (80 nL; (E); saline: n = 4 mice, photoactivation: 8.5 ± 1.323, drug: 22.5 ± 3.122, photoactivation plus drug: 10.25 ± 1.031; Halo: n = 4 mice, photoactivation: 10 ± 1.225, drug: 8 ± 1.472, photoactivation plus drug: 9.75 ± 0.8539; drug: saline vs. Halo, RM two-way ANOVA with Bonferroni’s test, P = 0.0477; photoactivation plus drug: saline vs. Halo, RM two-way ANOVA with Bonferroni’s test, P > 0.9999; Halo: photoactivation on vs. photoactivation plus drug, RM two-way ANOVA with Tukey’s test, P = 0.9988; Halo: drug vs. photoactivation plus drug, RM two-way ANOVA with Tukey’s test, P = 0.8608) of D2R antagonist Halo occluded further effect of photoactivation of SNc–lOFC projections on self-grooming time. Compared between indicated groups, *P < 0.05, **P < 0.01, and ***P < 0.001.

(a) Scheme of an optical device consisting of a 660 nm laser diode, a focusing lens, a mechanical shutter and a patch cable and a fiber optic cannula. Device is used for “via skin” and “via needle” selective photoactivation of the PAiRFP1 and PAiRFP2 expressing tumors in living mice. (b) Kinetics of via skin selective photoactivation of the PAiRFP1 (square) and PAiRFP2 (circle) expressing tumors with 660 nm laser beam of 1.5 mW total power. Photoactivation efficiency was calculated as (ROI_t−ROI₀)/ROI_max ×100, where ROI_t, ROI₀ and ROI_max were total radiant efficiencies of the respective areas after t seconds of illumination, before illumination and after complete photoactivation, respectively. (c) Overlay of the representative light and fluorescent images of a mouse bearing a four-week old MTLn3 tumor expressing PAiRFP1 before photoactivation (left image), after selective photoactivation of two small areas (middle image) and after complete photoactivation of the whole tumor (right image). Red arrows indicate areas where the light beam was applied. ROI, region of interest. (d) Average photoactivation contrast of the PAiRFP1 and PAiRFP2 expressing tumors in ROI1 and ROI2, represented on . Average photoactivation contrast values were obtained from 9 and 4 ROIs of PAiRFP1 and PAiRFP2 tumors, respectively. (e) Overlay of the representative light and fluorescent images of a mouse bearing a five-week old MTLn3 tumor expressing PAiRFP2 before photoactivation (first image), after selective via skin photoactivation of two small areas (second image), with subsequent placement of the needle into the tumor (third image), selective photoactivation via needle (fourth image) and complete photoactivation of the tumors (fifth image). Red arrows indicate areas photoactivated via skin. White dashed line indicates path of the needle inside of the tumor. Error bars, s.d. (n = 3). Scale bars, 1 cm.

Impact of transient photoactivation of the EIP-ring or P-ring neurons on the spatial orientation working memory. A, Photoactivation of the EIP-ring neurons (c105-GAL4;;UAS-CsChrimson.mVenus) during the last 30 s of the stimulus stage. Top, The stimulation protocol. Bottom, The radar plots for the first 30 s of the stimulus stage (left bottom), the last 30 s of the stimulus stage where the photoactivation was applied (middle bottom) and the poststimulus stage (right bottom) indicate that the orientation memory was intact. Note that the flies performed very little movement during the period of the photoactivation (). B, Same as in A, but with photoactivation during 20–30 s of the poststimulus stage. The radar plots are shown for the stimulus stage and the last 60 s of the poststimulus stage. The fixation behavior was abolished after the photoactivation. C, D, Same as in A, B, but with photoactivation of the P-ring neurons (;;VT5404-GAL4/UAS-CsChrimson.mVenus). The photoactivation during the poststimulus stage also abolished the fixation behavior. E, The of wild-type flies (w⁺) and flies in each photoactivation condition. Photoactivation in the stimulus stage caused minor or no impact on the orientation memory while photoactivation in the poststimulus stage abolished the memory. Performance of control groups (no photoactivation) are shown in Extended Data , , .