Fig. 5

Clonidine reversed the impulsive behavior but not hyper-locomotion produced by the activation of PH CaMKII + neurons. (A) Schematic diagram for behavioral tests. The mouse group injected with AAV-CaMKIIa-hM3Dq-mCherry into the PH was utilized. After administrating i.p. injection of CNO (1.5 mg/kg) to the mice and conducting behavioral tests, the same mice were given a combined injection of CNO and clonidine (1 mg/kg) the next day, followed by behavioral tests. (B) Moving velocity of the hM3Dq-CNO mice with or without clonidine injection (n = 9, p = 0.057, two-tailed paired t-test). (C) No change in interaction time with juvenile C57BL/6 mice of hM3Dq-CNO mice by clonidine (n = 7, p = 0.4364, two-tailed paired t-test). (D) Decrease of the number of jumping behavior of the hM3Dq-CNO mice in the open field induced by clonidine (n = 9, *p = 0.016). (E) Decrease in the number of cliff-jumping events of hM3Dq-CNO mice induced by clonidine (n = 13, **p = 0.008, two-tailed paired t-test). (F) No change by clonidine in the percentage of neurons expressing c-Fos among hM3Dq –expressing CaMKII + neurons in the PH. The hM3Dq-expressing mouse group was administrating i.p. injection of CNO or a combined injection of CNO and clonidine. After one hour, brains were processed for immunohistochemistry. The percentage of c-Fos-positive neurons among approximately 200 hM3Dq-mCherry-positive neurons was estimated for each animal. Average percentage values were then calculated from three animals per experimental group (***p < 0.001, one-way ANOVA with Bonferroni’s post hoc test). (G) Representative images showing c-Fos (green) expression in hM3Dq-mCherry (red) expressing neurons in the PH. Nuclei were stained with DAPI (blue)