Localisation of P2Y1 and P2Y4 receptors in dorsal root, nodose and trigeminal ganglia of the rat.Histochem Cell Biol 2003; 120(5):415-26HC
The presence and distribution of P2Y (nucleotide) receptor subtypes in rat sensory neurons has been investigated. RT-PCR showed that P2Y(1), P2Y(2), P2Y(4) and P2Y(6) receptor mRNA is expressed in sensory ganglia [dorsal root ganglion (DRG), nodose ganglion (NG) and trigeminal ganglion (TG)]. The regional and cellular distribution of P2Y(1) and P2Y(4) receptor proteins in these ganglia was investigated using immunohistochemistry. P2Y(1) polyclonal antibodies stained over 80% of the sensory neurons, particularly the small-diameter (neurofilament-negative) neurons. The P2Y(4) receptor antibody stained more medium- and large- (neurofilament-positive) diameter neurons than small-diameter neurons. P2Y(1) and P2Y(4) receptor immunoreactivity (P2Y(1)-IR and P2Y(4)-IR) was often coexpressed with P2X(3) receptor immunoreactivity (P2X(3)-IR) in subpopulations of neurons. Double immunohistochemistry showed that 73-84% of P2X(3) receptor-positive neurons also stained for the P2Y(1) receptor in DRG, TG and NG while only 25-35% also stained for the P2Y(4) receptor. Subpopulations of P2Y(1)-IR neurons were coexpressed with NF200, CGRP and IB(4); most P2Y(4)-IR neurons were coexpressed with NF200, while only a few neurons were coexpressed with CGRP (10-20%) or with IB(4) (1-2%). The results suggest that P2Y as well as P2X receptor subtypes contribute to purinergic signalling in sensory ganglia.