The nuclear GAPDH-HMGB cascade in cortical microglia regulates cognitive flexibility
We report a mechanism that underlies stress-induced cognitive inflexibility at the molecular level. In a mouse model under subacute stress in which deficits in rule shifting tasks were elicited, the nuclear glyceraldehyde dehydrogenase (N-GAPDH) cascade was activated specifically in microglia in the prelimbic cortex. The cognitive deficits were normalized with a pharmacological intervention with a compound (the RR compound) that selectively blocked the initiation of N-GAPDH cascade without affecting glycolytic activity. The normalization was also observed with a microglia-specific genetic intervention targeting the N-GAPDH cascade. Furthermore, hyperactivation of the prelimbic layer 5 excitatory neurons, which are known to be a neuronal substrate of cognitive inflexibility, was also normalized by the pharmacological and microglia-specific genetic interventions. The RR compound may offer a mechanism-driven, translational opportunity against stress-induced cognitive inflexibility. Taken together, we show a pivotal role of cortical microglia and microglia-neuron interaction in stress-induced cognitive inflexibility. We underscore the N-GAPDH cascade in microglia, which causally mediates stress-induced cognitive alteration.