Project description:Neuroligin-4 (NL4) loss-of-function mutations are strongly associated with monogenic heritable abnormalities linked with Autism Spectrum Disorder (ASD). NL4 mutation in mice causes ASD related alterations in both synaptic and behavioral phenotypes. Since microglia closely regulate synaptic development and are implicated as key players in ASD development and progression, we here studied microglial properties in the NL4-knock-out (NL4-/-) mouse model. We show that loss of NL4 caused altered behavior and impaired hippocampal gamma oscillations predominantly in male mice. In parallel, microglial density, morphology, and response to injury specifically in the CA3 region of the hippocampus were altered in NL4-/- males only. A transcriptomic and proteomic analysis revealed strong sexual dimorphism on molecular alterations in microglia of NL4-/-. Together, these results indicate that loss of NL4 affects not only neuronal network activity and behavior, but also changes the phenotype of microglia in a sex by genotype interaction .
