Figure 1. UCH-L1 promotes hippocampus-dependent learning and memory via regulating TrkB. A, Representative images of the DG region injected with AAV9 viruses. The immunofluorescence of GFP or mCherry represents AAV9-infected cells. 200 μm. B, Overexpression of UCH-L1 and the knockdown of TrkB in the DG of hippocampus, other parts of hippocampus, cortex, and striatum were examined by Western blot. C, Schematic representation of the experimental schedule to investigate the effects of UCH-L1 and TrkB on STM. D, E, CFC training and STM test were performed in the indicated mice. **p < 0.01 versus control or scramble group, ##p < 0.01, indicated groups, one-way ANOVA. All values are presented as mean ± SEM, n = 10–12 per group. F, G, Representative immunoblot images of the overexpression of WT UCH-L1 or C90S UCH-L1 (F) and the knockdown of TrkB levels (G). H–J, Representative immunoblot images (H) and densitometric analysis of TrkB ubiquitination (I) and protein levels (J) in the DG of mice. The control group consisted of naive mice injected with vehicle. n = 4 per group. **p < 0.01 versus control, #p < 0.05, indicated groups, one-way ANOVA. K, L, CFC training and STM test were performed in mice with TrkB inhibition (ANA12) or/and UCH-L1 overexpression. **p < 0.01 versus control group. #p < 0.05, indicated groups, one-way ANOVA. All values are presented as mean ± SEM, n = 8 per group. M, N, Representative immunoblot images (M) and densitometric analysis of TrkB activation (N) in the DG of mice. The control group consisted of naive mice injected with vehicle. n = 4 per group. **p < 0.01 versus control, one-way ANOVA.