Rho Guanine Nucleotide Exchange Factor 4 (Arhgef4) Deficiency Enhances Spatial and Object Recognition Memory.

Guanine nucleotide exchange factors (GEFs) play multiple functional roles in neurons. In a previous study, we reported that (Rho guanine nucleotide exchange factor 4) functioned as a negative regulator of the excitatory synaptic function by sequestering postsynaptic density protein 95 (PSD-95). However, the role of in behavior has not been examined. We performed comprehensive behavioral tests in knockout (KO) mice to investigate of the effects of deficiency. We found that the expressed PSD-95 particle size was significantly increased in hippocampal neuronal cultures from KO mice, which is consistent with the previous findings. KO mice exhibited general motor activity and anxiety-like behavior comparable to those of the wild type littermates. However, spatial memory and object recognition memory were significantly enhanced in the KO mice. Taken together, these data confirm the role of as a negative synaptic regulator at the behavioral level.