Behavioral and electrophysiological responses of Gr8a1 to multiple noxious tastants. A, Behavioral responses of w1118 and Gr8a1 using two-way choice assays and one of the following concentrations of chemicals: 6 mM caffeine, 1 mM quinine, 0.05 mM berberine, 0.1 mM denatonium, 0.1 mM lobeline, 0.5 mM papaverine, 0.5 mM strychnine or 0.2% DEET. n=5-12. The error bars indicate SEMs. B, Mean nerve firing responses from w1118 and Gr8a1 by performing tip recordings from S6 sensilla using the indicated concentrations of chemicals: 10 mM caffeine, 1 mM quinine, 0.1 mM berberine, 1 mM denatonium; 1 mM lobeline; 1 mM papaverine; 1 mM strychnine; 0.2% DEET. n=11-18. Shown are means ±SEMs.