Objective:To study the effects of LY294002, a phosphatidylinositol 3 kinase(PI3K) inhibitor, on the AKT/GSK3β/CRMP2 signaling pathway, and the effect of pathway alterations on the depression-like behavior and microtubulin proteins of SD rats.Methods:Sixteen adult male SD rats were randomly divided into LY294002 group and solvent DMSO group by blind method, 8 rats in each group.After anesthesia, the rats were subjected to stereotactic tube placement in the hippocampal CA1 area. After 1 week of the tube placement, stereoscopic injection of LY294002 or DMSO was given, and depression-like behaviors were detected. RT-qPCR technology was used to detect hippocampal AKT, GSK3β, CRMP2, and tubulin mRNA expression levels, and Western blot technology was used to detect the expression levels of hippocampal AKT, p-AKT, GSK3β, p-GSK3β, CRMP2, p-CRMP2, and microtubule dynamic-related proteins markers Acet-tubulin, Tyr-tubulin. Analysis and comparison of behavioral and molecular expression differences between the two groups were conducted.Results:The open field experiment showed that the central movement distance of the rats in the LY294002 group were significantly lower than those in the control group((3.64±2.17) cm, (31.51±12.68) cm; t=2.69, P=0.03), and the duration of the central area in the LY294002 group were also significantly lower than those in the control group((0.73±0.46)s, (4.85±2.10)s; t=2.33, P=0.04). The results of the forced swimming test showed that the immobility time of rats in the LY294002 group had upward trend, but the difference was not statistically significant. The sucrose preference results showed no significant difference in sugar water consumption between the two groups ( P>0.05). The RT-qPCR results showed that the expression level of CRMP2 mRNA in the LY294002 group decreased significantly ( P<0.05). Western blot results showed that compared with solvent DMSO group, the expression levels of p-AKT and p-GSK3β in the LY294002 group decreased ( P<0.05), the expression level of CRMP2 was decreased and the expression level of p-CRMP2 was significantly increased. At the same time, the expression level of Tyr-tubulin decreased, while Acet-tubulin level increased significantly, and the differences were statistically significant ( P<0.05). Conclusion:LY294002 affects AKT/GSK3β/CRMP2 signaling pathway, induces impairment of microtubular dynamic, and results in depression-like behavior in rats.