Effect of 5,7-dihydroxytryptamine on Auerbach's plexus in the ileum of guinea-pig

Action of 100 mg/kg of 5,7-dihydroxytryptamine on Auerbach's plexus in the ileum of the guinea-pig has been studied using Falck and Hillarp's formaldehyde condensation technique. The drug caused partial disappearance of the adrenergic nerve profiles initially but after 10 days of treatment all the lost fibers reappeared.