Upregulation of Cav3.2 T-type calcium channels in adjacent intact L4 dorsal root ganglion neurons in neuropathic pain rats with L5 spinal nerve ligation

Publication date: Available online 21 April 2018
Source:Neuroscience Research
Author(s): Qing-Ying Liu, Wen Chen, Shuang Cui, Fei-Fei Liao, Ming Yi, Feng-Yu Liu, You Wan
Besides the injured peripheral dorsal root ganglion (DRG) neurons, the adjacent intact DRG neurons also have important roles in neuropathic pain. Ion channels including Cav3.2 T-type calcium channel in the DRG neurons are important in the development of neuropathic pain. In the present study, we aimed to examine the expression of Cav3.2 T-type calcium channels in the intact DRG neurons in neuropathic pain. A neuropathic pain model of rat with lumbar 5 (L5) spinal nerve ligation (SNL) was established, in which the L4 DRG was separated from the axotomized L5 DRG, and the molecular, morphological and electrophysiological changes of Cav3.2 T-type calcium channels in L4 DRG neurons were investigated. Western blotting showed that total and membrane protein levels of Cav3.2 in L4 DRG neurons increased, and voltage-dependent patch clamp recordings revealed an increased T-type current density with a curve shift to the left in steady-state activation in the acutely isolated L4 DRG neurons in neuropathic pain rats. Immunofluorescent staining further showed that the membrane expression of Cav3.2 increased in CGRP-, IB4-positive small neurons and NF200-positive large ones. In conclusion, the membrane expression and the function of Cav3.2 T-type calcium channels are increased in the intact L4 DRG neurons in neuropathic pain rats with peripheral nerve injury like SNL.



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