Calcium signaling in Schwann cells at synaptic and extra-synaptic sites: active glial modulation of neuronal activity.
Glial cells are widely dispersed in the central nervous system (CNS) as well as in the peripheral nervous system (PNS). In the PNS, perisynaptic Schwann cells (PSCs) are the glial cells associated with the pre- and postsynaptic elements of the neuromuscular junction (NMJ). They, as other glial cells of the CNS, respond to high-frequency motor nerve stimulation with an increase in intracellular Ca(2+). In addition to detecting and responding to neurotransmission, PSCs are involved in short-term plasticity events where they depress neurotransmission through G-protein-dependent mechanisms and potentiate synaptic activity via Ca(2+)-dependent mechanisms. In this review, we will discuss evidence that outlines the role of PSCs in short- and long-term modulation of synaptic activity. We will also emphasize present functional similarities and differences in PSC activation at different NMJs. The importance of glial-neural interactions along myelinating axons will also be discussed.
Rousse
Isabelle
I
Département de Physiologie, Université de Montréal, Station Centre-Ville, Montreal, Québec, Canada H3C 3J7.|Centre de Recherche en Sciences Neurologiques, Université de Montréal, Station Centre-Ville, Montreal, Québec, Canada H3C 3J7.
Robitaille
Richard
R
Département de Physiologie, Université de Montréal, Station Centre-Ville, Montreal, Québec, Canada H3C 3J7.|Centre de Recherche en Sciences Neurologiques, Université de Montréal, Station Centre-Ville, Montreal, Québec, Canada H3C 3J7.
D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D006801:Humans; D023421:Models, Animal; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism*; D009469:Neuromuscular Junction / Q000378:metabolism* / Q000648:ultrastructure; D009473:Neuronal Plasticity / Q000502:physiology; D017933:Peripheral Nervous System / Q000166:cytology / Q000378:metabolism*; D012583:Schwann Cells / Q000166:cytology / Q000378:metabolism*; D013045:Species Specificity; D009435:Synaptic Transmission / Q000502:physiology