To analyse whether the neuroprotective effect on SH‐SY5Y cells exposed to H/R injury was related to GJ and/or HC functions of Cx43 we performed MTT‐viability test after adding GJ and/or HC inhibitors. We used CBX, a non‐selective GJIC inhibitor, IO to selectively target Cx43 homotypic GJs, and Gap19 to selectively inhibit Cx43 homotypic HCs. Results obtained from the titration of GJ and/or HC inhibitors (data not shown) suggested that the best inhibitor concentrations were 10 μM in culture medium. Our results demonstrated that H/R injured cultures treated with both GJ and HC chemical inhibitors significantly increase the cell viability over time compared to the control cultures exposed to H/R injury (Fig. 5).