Transmission to interneurons is via slow excitatory synaptic potentials mediated by P2Y(1) receptors during descending inhibition in guinea-pig ileum.

Background: The nature of synaptic transmission at functionally distinct synapses in intestinal reflex pathways has not been fully identified. In this study, we investigated whether transmission between interneurons in the descending inhibitory pathway is mediated by a purine acting at P2Y receptors to produce slow excitatory synaptic potentials (EPSPs).

Methodology/principal Findings: Myenteric neurons from guinea-pig ileum in vitro were impaled with intracellular microelectrodes.