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.