[Purpose] We have explored the possibility that protein phosphatase 5 (PP5), together with PP1 and PP2A, promotes desensitization of GABAB receptors and attenuates receptor action by dephosphorylating the 892nd serine residue of mouse GABAB receptors. In this study, we investigated the possibility that dephosphorylation of GABAB receptors in the hippocampal CA3 region affects the behavior of mice.
[Methods]The PP5 gene was cloned in a pAAV-CMV-GFP vector to create an adeno-associated viral vector (AAV). Mice in which the PP5 gene was overexpressed in the hippocampal CA3 region (PP5 mice) using the created AAV or mice in which AAV containing only the GFP gene was introduced as a control group (GFP mice) were created, and the effect on mouse behavior was analyzed.
[Results] In the Open field test, PP5 mice tended to stay in the center area longer than GFP mice, and a significant difference was observed especially for last 10 minutes of the session. In an elevated cross-maze test, PP5 mice tended to stay longer in open zones than GFP mice. In the Y-maze test, PP5 mice showed a decreasing trend in alternation behavior compared to GFP mice. In the novel object search test, a significant increase in the time of interest in the novel object was observed in GFP mice, but in PP5 mice there was no significant difference in the time of interest in the two objects.
[Conclusion] The behavioral experiments show that overexpression of PP5 in the CA3 region may affect mice to reduce anxiety-like behavior and cognitive function.