Pannexin-1 (Panx 1) is a large-pore membrane channel that is expressed widely in the nervous system and is involved in the physiological and pathological processes of some neurological diseases. Here, we investigate the expression of Panx 1 in a rat model of trigeminal neuralgia (TN). After chronic constriction injury (CCI) of the infraorbital nerve (ION), rats showed mechanical hypersensitivity responses to mechanical stimuli by von Frey hairs in contrast to sham rats. In comparison with sham rats, quantitative RT-PCR and western blot showed that Panx 1 expression was upregulated in the trigeminal ganglion (TG) of ION-CCI rats. Immunohistochemical staining indicated an endoneurial abundance of Panx 1 in neurons of TN after CCI, which was higher than that in sham rats. Our finding indicates that ION-CCI leads to a regulation of Panx 1 in the TG, which might contribute toward the development of TN.