Journal of Neuroscience, Vol 15, 253-261, Copyright © 1995 by Society for Neuroscience
Regulation of voltage-gated ion channels by NGF and ciliary neurotrophic factor in SK-N-SH neuroblastoma cells
SS Lesser and DC Lo
Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710.
Neurotrophic factors have powerful effects on neuronal differentiation and
the maintenance of neuronal phenotype, but understanding of their
regulation of one important aspect of neuronal function, excitability,
remains limited. We have examined the regulation of voltage-gated ion
channels by two unrelated neurotrophic factors, NGF and ciliary
neurotrophic factor (CNTF), in the SK-N-SH neuroblastoma cell line that is
responsive to both factors. NGF and CNTF have strikingly different neuronal
specificities and distributions in the nervous system, and might be
expected to have significantly different effects on neuronal function.
Using whole-cell, perforated-patch, and single-channel recording, we found
that treatment with NGF increased levels of voltage- gated sodium, calcium,
and potassium currents. In contrast, CNTF treatment increased levels of
potassium currents only. NGF and CNTF appeared to regulate the same
delayed-rectifier potassium current; in addition, NGF treatment resulted in
increased levels of a second potassium current component. Such differential
effects of neurotrophic factors on the expression of voltage-gated ion
channels would have profound effects on the excitability of target neurons
in vivo.