Effects of COX‑2 depletion on the neuronal structure.
Because hippocampal neuronal structure is believed to be the basis of learning and memory (Parra-Damas et al. , 2017), we then examined the alterations in neuronal structure in WT and COX-2KO mice hippocampus CA1 with Golgi staining. It revealed that dendritic complexity, which was evaluated by Sholl analysis, was stunted in response to COX-2KO (Fig. 3A, B). At the same time the dendrite length was less after COX-2KO (Fig. 3C). Furthermore, COX-2 depletion could not only decrease the density of dendritic spines but also reduce the percentage of mushroom-type spines (Fig. 3D, E, F). These data suggested that the loss of COX-2 gene resulted in neuronal structure disturbances in COX-2KO mice.
Effects of COX‑2 depletion on Gamma oscillation in hippocampus CA1.
Then we carried out local field potential (LFP) recording in the hippocampus CA1 by implanted 32-channel tetrodes. After analyzed the relative power of oscillations in COX-2KO and WT control mice, we observed no significantly altered in the relative power of theta (4–12Hz), alpha (13–15Hz), and beta (16–30Hz) oscillations (Figure 4 D). However, as illustrated in figure 4, we found a significant decrease in the relative power of low gamma (30-60Hz), and high gamma (60-90Hz) oscillation in COX-2KO mice, compared with WT ones (Figure 4 B, C, D). These results suggested that the deletion of COX-2 may lead to weaker gamma oscillation in the hippocampus CA1.