Figure 6. Effects of A₃ receptor activation on immunopurified ganglion cells

A: The P2X₇ receptor agonist BzATP (50 μM) led to large, repeated increases in Ca²⁺ when given in 15 s applications with an 8-10 min wash in between. B: Application of 10 μM adenosine attenuated the response to BzATP. Adenosine was given 2 min before and 2 min after the BzATP to maximize effectiveness. C: Adenosine reduced the mean Ca²⁺ response to BzATP. To control for slight desensitization, the first and third application were averaged together to obtain each value for "BzATP", while the second and fourth responses were averaged to obtain each "Bz+ Ado" level. The bars represent mean±SEM from 12 ganglion cells. The asterisk in this panel signifies p=0.003 (paired Student's t-test). D: The A₃ agonist Cl-IB-MECA (1 μM) produced a similar block of the BzATP response. E: Cl-IB-MECA also reduced the mean response to BzATP. Ca²⁺ elevations were averaged as in Panel C. The asterisk in this panel signifies p=0.019, n=6 (paired Student's t-test).