In vivocalcium imaging shows that satellite glial cells have increased activity in painful states

Abstract

AbstractSatellite glial cells (SGCs) are important for proper neuronal function of primary sensory neurons to whom they provide homeostatic support. Most research of SGC function has been performed within vitrostudies, but recent advances inin vivocalcium imaging and transgenic mouse models have enabled this first study of single cell SGC functionin vivoin male and female mice.We found that under most circumstances, SGCs do not respond in a time-locked fashion to neuronal firing. The one exception to this was suprathreshold stimulation of the sciatic nerve, which led to some time-locked signals, but only in painful inflammatory and neuropathic states. Surprisingly therefore, we conclude that most calcium signals in SGCs seem to develop at arbitrary intervals not directly linked to neuronal activity patterns.More in line with expectations, our experiments also revealed that the number of active SGCs was increased under conditions of inflammation or nerve injury. This could reflect the increased requirement for homeostatic support across dorsal root ganglion neuron populations, which are more active during such painful states.