Here we characterized the cross-inhibitory interactions between nicotinic and P2X receptors of celiac neurons from the guinea pig by recording whole-cell currents induced by 1mM ACh (I ACh ), 1mM ATP (I ATP ) and by the simultaneous application of both agonists (I ACh +ATP ). I ACh and I ATP were inhibited by hexamethonium (nicotinic channel blocker) and PPADS (P2X receptor antagonist), respectively. The amplitude of I ACh +ATP was equal to the current induced by the most effective agonist, indicating a current occlusion. Various observations indicate that I ACh +ATP is carried out through both nicotinic (nACh) and P2X channels: i) I ACh +ATP desensitisation kinetics were in between that of I ACh and I ATP ; ii) application of ATP+ACh, decreased I ACh and I ATP , whereas no cross-desensitisation was observed between nACh and P2X receptors; iii) ATP did not affect I ACh in the presence of PPADS or after P2X receptor desensitisation; and iv) ACh did not affect I ATP when nACh channels were blocked with hexamethonium or after nACh receptor desensitisation. Current occlusion is not mediated by activation of metabotropic receptors as it is: i) voltage dependent (was not observed at +5mV); ii) present at low temperature (10°C) and after inhibition of protein kinase activity (with staurosporine); and iii) absent at 30µM ATP and 30µM ACh (concentrations that should activate metabotropic receptors). In conclusion, current occlusion described here is similar to the previously reported myenteric neurons. This occlusion is likely the result of allosteric interactions between these receptors.