The effect of glycogen phosphorolysis on basal glutaminergic transmission

Astrocytic glycogen metabolism sustains neuronal activity but its impact on basal glutamatergic synaptic transmission is not clear. To address this issue, we have compared the effect of glycogen breakdown inhibition on miniature excitatory postsynaptic currents (mEPSCs) in rat hippocampal pure neuronal culture (PNC) and in astrocyte–neuronal co-cultures (ANCC). Amplitudes of mEPSC in ANCC were nearly twice as large as in PNC with no difference in current kinetics. Inhibition of glycogen phosphorylase reduced mEPSC amplitude by roughly 40% in ANCC being ineffective in PNC. Altogether, these data indicate that astrocyte–neuronal interaction enhances basal mEPSCs in ANCC mainly due to astrocytic glycogen metabolism.

Research highlights
► Astrocytes elevate amplitude of the miniature excitatory postsynaptic currents in hippocampal neurons.
► Astrocytes do not impact frequency and other kinetic parameters of the transmission.
► Inhibition of glycogen breakdown diminish the basal glutamatergic transmission in ANCC.