OBJECTIVETo determine the expression levels of calcium channel alpha-2-delta-1 (Cavalpha2delta-1) subunit in trigeminal ganglia (TG) and trigeminal spinal subnucleus caudalis C1-C2 spinal cervical dorsal horn(Vc/C2) after infraorbital nerve (ION) ligation injury in relation to the development of neuropathic nociception.

METHODSTwelve male SD rats were divided into two groups randomly, with 6 rats for each. In the ligation group, the ION was ligated by chromic gut loosely. In the sham operation group, the ION was exposed under same procedure but not ligated. The behavioral tests were conducted before 1 d and after 3, 6, 9, 12, 15 d with calibrated von Frey filaments. Cavalpha2delta-1 protein levels in TG and Vc/C2 were measured with Western blots 15 days after surgery.

RESULTSCompared with the sham operation group, changes of allodynia to mechanical stimulation on the territory of ligated ION were found from the 9th to 15th day after operation in the ligation group (P<0.05). The expression levels of Cavalpha2delta-1 in TG and Vc/ C2 after ION ligation injury upregulated significantly (P<0.01).

CONCLUSIONThe expression levels of Cavalpha2delta-1 in TG and Vc/C2 after ION ligation injury were upregulated and it may contribute to the pathogenesis of neuropathic nociception.