Microglial decline in the dentate gyrus is an important mechanism in the development of depression-like behaviors in stressed animals. Reversing this decline with low-dose lipopolysaccharide (LPS) can Show more
Microglial decline in the dentate gyrus is an important mechanism in the development of depression-like behaviors in stressed animals. Reversing this decline with low-dose lipopolysaccharide (LPS) can produce rapid antidepressant effects, yet the underlying mechanisms remain incompletely understood. Our previous work identified a critical role for astrocytic P2Y1 receptor (P2Y1R) activation and subsequent dentate gyrus extracellular signal-regulated kinase 1/2 (ERK1/2)-brain-derived neurotrophic factor (BDNF) signaling in the antidepressant effect of low-dose LPS. This study elucidates the signaling cascade linking astrocytic P2Y1R mobilization to the antidepressant effect of low-dose LPS. We found that low-dose LPS promoted glutamate release through ATP-triggered astrocytic P2Y1R signaling. Blockade of N-methyl-D-aspartic acid (NMDA) receptors, but not metabotropic receptors, and the GluN2B subtype of NMDA receptors abolished the antidepressant effect of low-dose LPS. GluN2B knockdown also abolished the reversal effect of low-dose LPS on CUS-induced depression-like behaviors and impairment of dentate gyrus ERK1/2-BDNF signaling. Moreover, chelating intracellular Ca Show less