The effects of the stable adenosine analogue, 2-chloroadenosine (2-CA) and basic fibroblast growth factor (bFGF) on myenteric neurones in dissociated cell culture were examined. 2-CA had no effect on neuronal numbers, but increased neurite length, in a dose-dependent manner. bFGF increased both the number of myenteric neurones and neurite length. When 2-CA was applied together with bFGF, an enhanced increase in neurite outgrowth, but no additional increase in neuronal numbers was observed. 2-CA-induced effects were blocked by the adenosine antagonist 8-(p-sulphophenyl)theophylline. These results show, for the first time, that both purines and bFGF may have trophic actions on myenteric neurones and also indicate that purines enhance some effects of bFGF, in a synergistic manner.