Downregulation of voltage-gated potassium channel alpha gene expression by axotomy and neurotrophins in rat dorsal root ganglia.
Injury to peripheral nerves causes a neuropathic pain which is difficult to relieve, but the underlying mechanism remains largely unknown. In previous studies we reported that voltage-gated potassium (Kv) channel alpha genes are downregulated in the dorsal root ganglia (DRG) following chronic constriction of the sciatic nerve [Kim et al. (2002)], suggesting a relationship between electrical abnormalities of the injured neurons and Kv gene expression. Here, we examined expression of the Kv 1.2, 1.4, and 4.2 genes in the DRG following transection of the sciatic nerve, and investigated the effect of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) on expression of those mRNAs, using the reverse transcription-polymerase chain reaction. Expression of these mRNAs was reduced by axotomy and by exposure to BDNF, and NT-3 treatment. However no significant change was detected following NGF treatment. Our findings suggest that downregulation of Kv channel gene expression in DRG neurons by neurotrophins may play an important role in long-term changes of neuronal excitability following nerve injury.
Park
So Yun
SY
Department of Anatomy, School of Medicine, Kyungpook National University, Daegu 700-422, Korea.
Choi
Jun Young
JY
Kim
Rae Uk
RU
Lee
Young Sup
YS
Cho
Hee Jung
HJ
Kim
Dong Sun
DS
D000818:Animals; D019771:Axotomy; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology; D015536:Down-Regulation / Q000502:physiology*; D005727:Ganglia, Spinal / Q000378:metabolism*; D020932:Nerve Growth Factor / Q000494:pharmacology; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000601:surgery
D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D024642:Potassium Channels, Voltage-Gated; D020932:Nerve Growth Factor