Communication between neurons and glial cells are crucial to establish and maintain brain function. Some of these interactions are activity-dependent, yet it remains unexplored how acute changes in neuronal activity affect neuron-to-glial dynamics. Here, we use excitatory and inhibitory designer receptors exclusively activated by designer drugs (DREADD) based chemogenetic methods to study the effects of acute manipulations of a subpopulation of layer 5 cortical projection and dentate gyrus neurons in adult (Rbp4Cre) mouse brain after 90 minutes. We show that acute chemogenetic neuronal activation leads to microglia hyperactivation, reactive astrogliosis, increased parvalbumin expression in interneurons and lower synaptic marker expression. Whereas acute chemogenetic ‘silencing’ of the same neurons reduce microglia activity, inhibit astrocytic reactivity, increase synaptic density, but has no effect on parvalbumin expression. Acute changes in neuronal activity elicit rapid effects on the interactions between glial cells, glutamatergic and GABAergic neuronal networks.
