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. 2021 Oct 20;118(43):e2110934118. doi: 10.1073/pnas.2110934118

Fig. 4.

Fig. 4.

Optogenetic stimulation of the CnF increases locomotor activity in Vglut2-ChR2-EYFP mice lesioned with 6-OHDA. (A) Vglut2-ChR2-EYFP mice were either injected in the striatum with vehicle or 6-OHDA (see Materials and Methods) and implanted ∼500 μm above the right CnF with an optic fiber. After 3 d, the effects of optogenetic stimulation of the CnF were tested in the open-field arena. (B) Photomicrograph showing the position of the optic fiber right above the CnF. (C) Magnification of the yellow square in B, showing the expression of ChR2-EYFP at the level of the CnF. IC, inferior colliculus; PAG, periaqueductal gray; PPN, pedunculopontine nucleus. (D) Location of the optic fibers after the histology of mice injected in the striatum with vehicle (green circles) or 6-OHDA (orange circles). (E and F) Raw data showing the effects of CnF optogenetic stimulation with a 470-nm laser in a mouse injected in the striatum with vehicle (E) (10 s train, 20 Hz, 10 ms pulses, and 5% of laser power), or with a 470-nm laser in a mouse injected in the striatum with 6-OHDA (F) (10% of laser power). (G and I) Locomotor speed (mean ± SEM) before, during, and after a 10-s optogenetic stimulation (onset at t = 0 s) with a 470-nm laser in a single animal (G) (5% of laser power) or in a pool of six animals injected in the striatum with vehicle (I) (10 stimulations per animal and 5 to 20% of laser power). (H and J) Locomotor speed (mean ± SEM) before, during, and after a 10-s optogenetic stimulation (onset at t = 0 s) with a 470-nm laser in a single animal (H) (10% of laser power) or in a pool of five animals injected in the striatum with 6-OHDA (J) (10 stimulations per animal and 5 to 20% of laser power). (K–R) Evolution of locomotor parameters before (−10 to 0 s), during (0 to 10 s), and after (10 to 20 s and 20 to 30 s) optogenetic stimulation of the CnF with a 470-nm laser in six animals injected in the striatum with vehicle (K, M, O, and Q) and in five animals injected with 6-OHDA (L, N, P, and R). *P < 0.05, **P < 0.01, ***P < 0.001, Student–Newman–Keuls test after a one-way ANOVA for repeated measures (P < 0.001 in K, M, N, Q, and R). +P < 0.05, Student–Newman–Keuls test after a Friedman repeated measures ANOVA on ranks (P < 0.05 in L and P; P < 0.01 in O).