Objective      To investigate the expression and distribution of transient receptor potential canonical channel 3 (TRPC3) in the cortical focus of epilepsy patients with tuberous sclerosis complex (TSC)

and to explore the mechanism of TRPC3 involvement in TSC-induced epileptic seizure.       Methods      Twelve cases of TSC epileptic brain tissues (TSC group) confirmed by pathological examination from June 2008 to December 2010 and seven cases of non-epileptic brain tissues (CTX group) were enrolled in our study. The expression and distribution of TRPC3 were observed by Western blotting

immunohistochemistry and immunofluorescence double labeling in these tissues.       Results      Western blot analysis showed that the TRPC3 expression was significantly higher in the TSC group than in the CTX group [relative optical density (ROD) 0.65±0.08 vs 0.36±0.06

P0.05]. The immunohistochemistry and immunofluorescence double labeling results showed that the intensity score of TRPC3 was higher in the TSC group than in the CTX group

and TRPC3 was specifically overexpressed in the misshapen neurons of the cortical focus

including dysplastic neurons (DNs) and giant cells (GCs).       Conclusion      The abnormally increased expression of TRPC3 in epileptic cortex of TSC patients and the specific cell distribution pattern may be closely involved in the pathogenesis of intractable epilepsy.