Temperature dependence of rapidly adapting mechanically activated currents in rat dorsal root ganglion neurons

NEUROSCIENCE LETTERS

卷:522

Article

Jia, Zhanfeng^1,2  Ling, Jennifer¹  Gu, Jianguo G.¹ 

[1] Univ Cincinnati, Coll Med, Dept Anesthesiol, Cincinnati, OH 45267 USA

[2] Hebei Med Univ, Dept Pharmacol, Shijiazhuang 050017, Peoples R China

关键词: Rapidly adapting;    Mechanically activated channel;    Piezo2;    Temperature;    Dorsal root ganglion;   

DOI  :  10.1016/j.neulet.2012.06.024

来源: Elsevier

【 摘 要 】

Rapidly adapting mechanically activated channels (RA) are expressed on somatosensory neurons and thought to play a role in mechanical transduction. Because mechanical sensations can be significantly affected by temperatures, we examined thermal sensitivity of RA currents in cultured dorsal root ganglion (DRG) neurons to see if RA channel activity is highly temperature-dependent. RA currents were evoked from DRG neurons by membrane displacements and recorded by the whole-cell patch-clamp recording technique. We found that RA currents were significantly enhanced by warming temperatures from 22 to 32 degrees C and reduced by cooling temperatures from 24 to 14 degrees C. RA channel activation exhibited steep temperature-dependence with a large temperature coefficient (Q10 > 5) and a high activation energy (Ea > 30 kcal/mol). We further showed that RA channel activation by mechanical stimulation led to membrane depolarization, which could result in action potential firing at 22 degrees C or 32 degrees C but not at 14 degrees C. Taken together, our results provide the measurements of thermal dynamics and activation energy of RA channels, and suggest that a high energy barrier is present for RA channels to open. These findings are in agreement with temperature sensitivity of mechanical sensations in mammals. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

【 授权许可】

Free