Neuronal-type Na+ and K+ channels in rabbit cultured Schwann cells

Abstract

Nerve axons in the central and peripheral nervous system are normally surrounded by satellite cells. These cells, known as Schwann cells in the peripheral nervous system, interact with axons to form a myelin sheath, so allowing nerve impulses to proceed at high speed. Schwann cells are thought to differ from neurones in their membrane properties in one important aspect: they lack excitability. Using the patch-clamp technique we have now measured directly the ionic currents across the membrane of single Schwann cells cultured from newborn rabbits. Surprisingly, we found that these Schwann cells possess voltage-gated sodium and potassium channels that are similar to those present in neuronal membranes.

Gain-of-function mutation of a voltage-gated sodium channel NaV1.7 associated with peripheral pain and impaired limb development

“…Bones are innervated by sensory and sympathetic nerves to regulate local bone metabolism (33,34). Sodium channels have been shown to be expressed in non-excitable cells, such as Schwann cells and glial cells (35)(36)(37), and expression of Na V 1.2 channels has been reported in osteoblasts during embryogenesis (38). Bone resorption has been reported to be increased following sensory nerve denervation in adult rats (39).…”

The Clustering of Axonal Sodium Channels during Development of the Peripheral Nervous System

“…Schwann cell Na ϩ channel label was virtually absent by day P2. There is evidence for the presence of Na ϩ channels in glia, but agreement with respect to myelinating Schwann cells is lacking (Chiu et al, 1984;Howe and Ritchie, 1990;Ritchie et al, 1990;Sontheimer et al, 1992;Chiu, 1993).…”

Potassium channel regulation in Schwann cells during early developmental myelinogenesis

“…We focused only on voltage-gated potassium channels in cells visibly beginning to elaborate myelin and found not only an outward rectifying potassium channel which resembles that described in previous studies of Schwann cells (Chiu et al, 1984;Shrager et al, 1985;Chiu, 1987Chiu, , 1988Chiu and Wilson, 1989), but also an inward rectifying potassium channel which previously has not been described for Schwann cells. Both channels disappear from the soma as myelination proceeds.…”

“…However, patch-clamp recordings recently have provided evidence for the existence of neuronallike, voltage-gated ion channels in mammalian Schwann cells under cultured conditions (Chiu et al, 1984;Gray and Ritchie, 1985;Shrager et al, 1985), hinting that the Schwann cell's role may be more active than the traditional view implies. Already, accumulating evidence has revealed an interesting relation between channel expression and cell phenotype.…”