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Figure 1. The genotyping of COX-2KO mice and the effect of COX‑2 depletion on the learning and memory ability in MWM and NOR test. (A) Genotyping of COX-2 by PCR. The 800 bp DNA fragments were detected in WT (COX-2+/+) mice; 400 bp were detected in COX-2KO homozygote (COX-2-/-) mice; both 400 and 800 bp DNA fragments could be detected in COX-2KO heterozygote (COX-2+/-) mice. (B) COX-2 protein expression in hippocampus in WT and COX-2KO mice were detected by western blot. (C) Body weight of WT and COX-2KO mice.(D) Body temperature of WT and COX-2KO mice. (E)Expression of mRNAs for TNF-a, iNOS and IL-1β in the hippocampus of WT and COX-2KO mice. (F) The escape latency in finding a target platform during the 5-day period training trials. (G) Time spent in the target quadrant on the last day without platform.(H) Counts crossing the platform area on the last day without platform. (I) Swimming speed of WT and COX-2KO mice on the last day of MWM. (J) Total distance traveled of WT and COX-2KO mice on the last day of MWM. (K) The track of probe test.(L) The recognition index. (J) Total distance traveled of WT and COX-2KO mice in NORT. (The bars indicate the means ± SEM; n = 10 per group; *𝑝 < 0.05).
Figure 2. Effects of COX‑2 depletion on the SYP and PSD95. (A)Representative immunofluorescence photomicrographs of SYP, PSD95 and DAPI in hippocampus CA1. (B) Quantification of SYP (+) and PSD95 (+) fluorescence intensity. (C) The expression of SYP and PSD95 protein in the hippocampus of WT and COX‑2KO mice was detected by Western Blot. (The bars indicate the means ± SD; n = 5 per group; *𝑝 < 0.05; Scale bar = 100μm)
Figure 3. Effects of COX‑2 depletion on the neuronal structure. (A) Representative Golgi staining photomicrographs in hippocampus CA1. Bar=20μm. (B) The Sholl analysis was performed to evaluate the dendritic complexity. n=25 neurons from 5 mice for each group. (C) Quantitative analysis of the dendrite length.(D) Representative Golgi staining photomicrographs for the dendritic spines. Bar=2μm. (E) Quantitative analysis of the spine density. (F) Quantitative analysis of the percentage of mushroom spines. (The bars indicate the means ± SD; n = 5 per group; *𝑝 < 0.05)
Figure 4. Effects of COX‑2 depletion on Gamma oscillation in hippocampus CA1. (A) Representative LFP and filtered theta, alpha, beta, low gamma and high gamma component of the signal from WT and COX‑2KO mice. (B) Representative Power spectrogram of LFP from WT and COX‑2KO mice. (C) Power spectral density of LFP from 0 to 120Hz (left) and 30 to 120Hz (right) in WT and COX‑2KO mice.(D) The power of theta oscillation (4–12Hz), alpha oscillation (13–15Hz), beta oscillation (16–30Hz), low gamma oscillation (30–60Hz) and high gamma oscillation (60–120Hz). (The bars indicate the means ± SD; n = 5 per group; *𝑝 < 0.05)
Figure 5. Effects of COX‑2 depletion on the expression of PGs. (A-E) Results of PGE2, PGD2, PGF2a, 6-keto-PGF1a and TxB2 levels by HPLC/mass spectrometry in the hippocampus of WT and COX-2KO mice. (The bars indicate the means ± SEM; n = 5 per group; *𝑝 < 0.05)
Figure 6. Effects of COX‑2 depletion on cAMP/PKA/CREB/BDNF signaling pathway. (A) The expression of PKA, p-PKA, CREB, p-CREB, and BDNF protein in the hippocampus of WT and COX‑2KO mice was detected by Western Blot. (B) The expression of cAMP was detected by Elisa. (The bars indicate the means ± SD; n = 5 per group; *𝑝 < 0.05)
Figure 7. Effects of Celecoxib and PGE2 on SYP/PSD95 and cAMP/PKA/CREB/BDNF signaling in N2a cells. (A) RT-qPCR result of COX-2 mRNA in N2a cells treated with Celecoxib in different concentration. (B) ELISA result of cAMP level. (C)Western blot result of COX-2, SYP, PSD95, PKA, p-PKA, CREB, p-CREB and BDNF proteins in N2a cells treated with Celecoxib and PGE2. (The bars indicate the means ± SD; n = 4 per group; *𝑝 < 0.05)