The effect of neurotrophic factors on morphology, TRPV1 expression and capsaicin responses of cultured human DRG sensory neurons

Neurosci Lett. 2006 May 15;399(1-2):51-6. doi: 10.1016/j.neulet.2006.01.046. Epub 2006 Feb 14.


We have studied the effect of key neurotrophic factors (NTFs) on morphology, levels of the vanilloid receptor-1 (TRPV1) and responses to capsaicin in adult human sensory neurons in vitro. Avulsed dorsal root ganglia (DRG, n = 5) were cultured with or without a combination of nerve growth factor (NGF), glial cell (line)-derived growth factor (GDNF) and neurotrophin3 (NT3) for 5 days. In the absence of NTFs, the diameter of neurons ranged from 20 to 100 microm (mean 42 +/- 4 microm). Adding NTFs caused a significant increase in neuronal sizes, up to 120 microm (mean diameter 62 +/- 5 microm, P < 0.01, t-test), an overall 35% increase of TRPV1-positive neurons (P < 0.003), and notably of large TRPV1-positive neurons > 80 microm (P < 0.05). Responses to capsaicin were significantly enhanced with calcium ratiometry (P < 0.0001). Short duration (1h) exposure of dissociated sensory neurons to NTFs increased numbers of TRPV1-positive neurons, but not of TRPV3, Nav 1.8 and IK1 and the morphological size-distribution remained similar to intact post-mortem DRG neurons. NTFs thus increase size, elevate TRPV1 levels and enhance capsaicin responses in cultured human DRG neurons; these changes may relate to pathophysiology in disease states, and provide an in vitro model to study novel analgesics.

MeSH terms

  • Adult
  • Capsaicin / pharmacology*
  • Cell Size
  • Cells, Cultured
  • Ganglia, Spinal / cytology*
  • Glial Cell Line-Derived Neurotrophic Factor / metabolism
  • Humans
  • Male
  • NAV1.8 Voltage-Gated Sodium Channel
  • Nerve Growth Factor / metabolism
  • Nerve Growth Factors / metabolism*
  • Neurons, Afferent / cytology
  • Neurons, Afferent / drug effects*
  • Neurons, Afferent / metabolism
  • Neurotrophin 3 / metabolism
  • Potassium Channels, Calcium-Activated / biosynthesis
  • Sodium Channels / biosynthesis
  • TRPV Cation Channels / biosynthesis*


  • GDNF protein, human
  • Glial Cell Line-Derived Neurotrophic Factor
  • NAV1.8 Voltage-Gated Sodium Channel
  • Nerve Growth Factors
  • Neurotrophin 3
  • Potassium Channels, Calcium-Activated
  • SCN10A protein, human
  • Sodium Channels
  • TRPV Cation Channels
  • TRPV1 protein, human
  • TRPV3 protein, human
  • Nerve Growth Factor
  • Capsaicin