Fig. 4
Optogenetic inhibition of TNC astrocytes alleviates pain induced by ION constriction. A Schematic diagram of the optic modulation site in rat brain. B Light stimulation parameters during the behavior test. C Optic inhibition of TNC astrocytes increased mechanical withdrawal threshold in ipsilateral whisker pad during the von Frey filament test in TN/eNpHR + rats. Data are presented as the mean ± SD. Two-way ordinary ANOVA with Sidak’s multiple comparisons tests, n = 8/group, ***P = 0.0006 compared to light off condition of TN/eNpHR + rats. Two-way ordinary ANOVA with Sidak’s multiple comparisons tests, n = 8/group, ****P < 0.0001 compared to light on condition between TN/eNpHR + and TN/eNpHR- rats (D) Schematic diagram of rats subjected to von Frey filaments (upper) and acetone (lower) tests with a tethered system for optogenetic manipulations. E Astrocyte-specific optic inhibition of TNC decreased the number of episodes during the acetone test for cold allodynia in TN/eNpHR + rats. Data are presented as the mean ± SD. Two-way ordinary ANOVA with Sidak’s multiple comparisons tests, n = 8/group, **P = 0.0075 compared to light off condition of TN/eNpHR + rats. Two-way ordinary ANOVA with Sidak’s multiple comparisons tests, n = 8/group, *P = 0.0160 compared to light on condition between TN/eNpHR + and TN/eNpHR- rats. F The pressure threshold during the air puff test was improved during TNC astrocyte inhibition with a yellow laser in TN/eNpHR + rats. Two-way ordinary ANOVA with Sidak’s multiple comparisons tests, n = 8/group, ****P < 0.0001 compared to light off condition of TN/eNpHR + rats. Two-way ordinary ANOVA with Sidak’s multiple comparisons tests, n = 8/group, ****P < 0.0001 compared to light on condition between TN/eNpHR + and TN/eNpHR- rats. G Schematic diagram of rat subjected to open field test with a tethered system for optogenetic intervention (H, I) Representative trajectory and exploration heatmap of TN/eNpHR + rats during light on and off conditions. J, K The number of explored areas (***P = 0.0007) and mobility rate (***P = 0.0004, expressed as a percentage) were considerably improved in TN/eNpHR + animals under light-on conditions compared to those under light-off conditions. No significant differences were observed in the other groups. Data are presented as the mean ± SD. Two-way ordinary ANOVA with Sidak’s multiple comparisons tests, n = 8/group, (explored areas, ****P < 0.0001; mobility rate, **P = 0.0012) compared to light on condition between TN/eNpHR + and TN/eNpHR- rats