Astrocytic neuroligin 3 regulates social memory and synaptic plasticity through adenosine signaling in male mice.

Social memory impairment is a key symptom of many brain disorders, but its underlying mechanisms remain unclear. Neuroligins (NLGs) are a family of cell adhesion molecules essential for synapse development and function and their dysfunctions are linked to neurodevelopmental and neuropsychiatric disorders, including autism and schizophrenia. Although NLGs are extensively studied in neurons, their role in glial cells is poorly understood. Here we show that astrocytic deletion of NLG3 in the ventral hippocampus of adult male mice impairs social memory, attenuates astrocytic Ca²⁺ signals, enhances the expression of EAAT2 and prevents long-term potentiation, and these impairments are rescued by increasing astrocyte activity, reducing EAAT2 function or enhancing adenosine/A2a receptor signaling. This study has revealed an important role of NLG3 in astrocyte function, glutamate homeostasis and social memory and identified the glutamate transporter and adenosine signaling pathway as potential therapeutic strategies to treat brain disorders.