Highlights d AMPA receptors (AMPARs) with modified properties are expressed in OPCs in vivo d Channel-pore mutations of AMPARs affect functional properties of axon-OPC synapses d Expression of Ca 2+ -permeable AMPARs alters proliferation and differentiation of OPCs d Introducing the C-tail of the GluA2 subunit of AMPARs reduces differentiation of OPCs

In the developing and adult brain, oligodendrocyte precursor cells (OPCs) are influenced by neuronal activity: they are involved in synaptic signaling with neurons, and their proliferation and differentiation into myelinating glia can be altered by transient changes in neuronal firing. An important question that has been unanswered is whether OPCs can discriminate different patterns of neuronal activity and respond to them in a distinct way. Here, we demonstrate in brain slices that the pattern of neuronal activity determines the functional changes triggered at synapses between axons and OPCs. Furthermore, we show that stimulation of the corpus callosum at different frequencies in vivo affects proliferation and differentiation of OPCs in a dissimilar way. Our findings suggest that neurons do not influence OPCs in “all-or-none” fashion but use their firing pattern to tune the response and behavior of these nonneuronal cells.