Satellite glial cells modulate cholinergic transmission between sympathetic neurons

Abstract

Postganglionic sympathetic neurons and satellite glial cells are the two major cell types of the peripheral sympathetic ganglia. Sympathetic neurons project to and provide neural control of peripheral organs and have been implicated in human disorders ranging from cardiovascular disease to peripheral neuropathies. Here we show that satellite glia regulate synaptic activity of cultured postnatal sympathetic neurons, providing evidence for local ganglionic control of sympathetic drive. In addition to modulating neuron-to-neuron cholinergic neurotransmission, satellite glia promote synapse formation and contribute to neuronal survival. Examination of the cellular architecture of the rat sympathetic ganglia in vivo shows this regulation of neuronal properties takes place during a developmental period in which neuronal morphology and density are actively changing and satellite glia enwrap sympathetic neuronal somata. Cultured satellite glia make and release factors that promote neuronal activity and that can partially rescue the neurons from cell death following nerve growth factor deprivation. Thus, satellite glia play an early and ongoing role within the postnatal sympathetic ganglia, expanding our understanding of the contributions of local and targetderived factors in the regulation of sympathetic neuron function.

Emerging importance of satellite glia in nervous system function and dysfunction

“…This selective activation correlates with the presence of TLR4 in sensory neurons, and their absence in sympathetic ones. The results above are supported by a recent study 131 , which showed that SGCs in sympathetic ganglia release factors that augment cholinergic synaptic transmission. SGCs also promote synapse formation and contribute to neuronal survival 131 .…”

“…The results above are supported by a recent study 131 , which showed that SGCs in sympathetic ganglia release factors that augment cholinergic synaptic transmission. SGCs also promote synapse formation and contribute to neuronal survival 131 . Thus, SGCs play crucial roles in both development and maintenance of sympathetic function.…”

Advances in 3D neuronal microphysiological systems: towards a functional nervous system on a chip

“…And while not necessarily a barrier-forming cell, satellite glia within the periphery envelope dorsal root ganglion somata and perform a litany of functions related to pain processing (Costa and Moreira Neto 2015 ), sympathetic transmission and neuron survival (Enes et al . 2020 ). There is also evidence to suggest that satellite glia serve as a reservoir of arrested Schwann cells that, via regulation of cadherin-19, may leave the soma and become mature, myelinating cells should cues arise, such as in injury (George et al .…”

“…Notably, these choroid plexus organoids contained pertinent transporters integral to barrier functionality and also secreted a host of relevant proteins one would expect to find in cerebral spinal fluid (49/50 of the most detected proteins in the organoid model are also found within in vivo samples). And while not necessarily a barrier-forming cell, satellite glia within the periphery envelope dorsal root ganglion somata and perform a litany of functions related to pain processing (Costa and Moreira Neto 2015), sympathetic transmission and neuron survival (Enes et al 2020). There is also evidence to suggest that satellite glia serve as a reservoir of arrested Schwann cells that, via regulation of cadherin-19, may leave the soma and become mature, myelinating cells should cues arise, such as in injury (George et al 2018).…”

More Than Mortar: Glia as Architects of Nervous System Development and Disease

“…Cortex glia exclusively surround neuronal cell bodies. Morphologically, cortex glia are most akin to mammalian satellite glial cells, which have also been shown to promote survival of postganglionic sympathetic neurons in the peripheral nervous system (PNS) (Enes et al, 2020). Further mechanistic and descriptive study of each of these cell types is needed before concluding the functional equivalency of cortex and satellite glia.…”