Figure 4. Dose-response effects of adenosine agonists on the dorsal root potential (DRP). (A) Superimposed traces of the DRP before, during application of different concentrations of NECA, and then reversed by theophylline (25 micro Meter). (B) Dose-response curves for the inhibition of the DRP by N6-cyclohexyladenosine (CHA), 5'-N-ethylcarboxamidoadenosine (NECA), CGS 21680, and CHA in the presence of 100 nm 8-cyclopentyl-theophylline. Data are mean +/- SEM (n = 4-5). However, the error bars for some data points fall within the symbols.