ULTRASTRUCTURAL-LOCALIZATION OF P2X(3) RECEPTORS IN RAT SENSORY NEURONS

WE used isolated IgG antibodies selective for P2X(3) receptors to stud y the ultrastructural distribution of these receptors in rat sensory n eurons. In trigeminal ganglia, P2X(3) receptor immunoreactivity occurr ed in small and large nerve cell bodies and their processes. Endoplasm ic reticulum and Golgi apparatus were heavily stained; cytoplasmic mat rix was faintly to moderately stained. In synaptic glomeruli in lamina II of cervical dorsal horn, P2X(3) receptor-immunoreactive core termi nals were postsynaptic to unlabelled vesicle-containing dendrites and axons. In the nucleus of the solitary tract, receptor-positive boutons synapsed on dendrites and cell bodies and had complex synaptic relati onships with other axon terminals and vesiculated dendrites. These obs ervations identify sites from which ATP could be released to influence sensory signalling within the central nervous system. NeuroReport 9: 2545-2550 (C) 1998 Rapid Science Ltd.