Gap Junction Blockers in Zebrafish

Gap junction blockers heptanol (500 μM, Sigma-Aldrich) (Guan et al., 1997 (link); Johnston et al., 1980 (link); Weingart and Bukauskas, 1998 (link)) or propofol (10 μM, Sigma-Aldrich) (Mantz et al., 1993 (link); Wentlandt et al., 2006 (link)) were added to the bath for at least 30 min to allow adequate diffusion before imaging acquisition. Additional putative gap junction blockers were also tested in preliminary studies but were difficult to dissolve in embryo media (carbenoxolone) or toxic (mefloquine) and not included here. For all drugs, toxicity tests were performed wherein multiple concentrations of each drug were bath applied to 3 agar-embedded larvae for 1.5 hours, then heart rate was monitored to identify maximum non-toxic concentration of each drug to be used. During all imaging studies, heart rate was continuously monitored as a means to confirm vitality, and fish with no or barely observable heart activity after imaging data acquistions were excluded from analysis.