Facilitation of Ih channels by P2Y1 receptors activation in Mesencephalic trigeminal neurons

P2Y1 receptors, a subset of G-protein coupled receptors, have been shown to participate in sensory transduction in the periphery nervous system. However, little is known about their sensory function in the central nervous system. Here, by using immunohistochemistry, we showed that P2Y1 receptors are predominantly localized in the somata of Mesencephalic trigeminal neurons (Mes V neurons), the primary sensory neurons in brainstem. Whole-cell voltage-clamp recording revealed that ADP-β-S, a P2Y receptor agonist, enhanced the activity of hyperpolarization-activated cation channels (Ih channels) in Mes V neurons and that the activity-enhancing effect of ADP-β-S could be blocked by a specific P2Y1 receptor antagonist, MRS 2179. Taken together, these results suggested a possible role of P2Y1 receptors in the information transduction of central sensory neurons through regulating Ih channel activities.