TTX-sensitive action potentials and excitability of adult rat sensory neurons cultured in serum- and exogenous nerve growth factor-free medium.
The excitability of adult rat dorsal root ganglion (DRG) neurons cultured in the absence of serum and exogenously added nerve growth factor (NGF) was studied. Current-clamp recordings revealed the presence of tetrodotoxin (TTX)-sensitive action potentials. Voltage-clamp recordings demonstrated the presence of both inward and outward currents. The inward Na+ current had a maximal amplitude near -10 mV and was completely blocked by TTX. A sustained Ca2+ inward current and a slowly activating outward K+ current were also observed. TTX-sensitive and TTX-resistant action potentials have been observed in previous studies in DRG neurons cultured in the presence of serum. By contrast, in the study reported here, only TTX-sensitive action potentials and Na+ currents were found in the neurons cultured in the absence of serum and nerve growth factor.
Aguayo
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Section of Electrophysiology, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD 20852.
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White
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D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003470:Culture Media; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000166:cytology; D008297:Male; D009414:Nerve Growth Factors / Q000502:physiology*; D009475:Neurons, Afferent / Q000187:drug effects*; D011188:Potassium / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013779:Tetrodotoxin / Q000494:pharmacology*
D003470:Culture Media; D009414:Nerve Growth Factors; D013779:Tetrodotoxin; D011188:Potassium; D002118:Calcium