ADORA2A and Crohn ileitis: Considering that, under normal physiological conditions, endogenous adenosine facilitates [3H]ACh release from stimulated myenteric neurons through the preferential activation of pre-junctional A2A receptors (Duarte-Araújo et al., 2004a), one may speculate that cholinergic hypoactivity in TNBS-induced ileitis is dependent on the loss of adenosine A2A receptor-mediated neurofacilitation.