Localisation of glutamate receptor binding sites and mRNAs to the dorsal horn of the rat spinal cord.

The autoradiographic distribution of binding sites for [3H]AMPA, [3H]kainate, [3H]MK-801 and [3H]L-glutamate and the in situ hybridization of GluR-A, GluR-B, GluR-C and GluR-D in rat spinal cord sections were determined. All of the radioligands had similar localisations with the dorsal horn being the most intensely labelled region. In the in situ hybridization experiments only the GluR-B mRNA was detected at high levels in the spinal cord with predominant expression in the substantia gelatinosa. These results support electrophysiological evidence for the presence of glutamate activated neurones in the spinal cord and suggest that these excitatory pathways are confined mainly to the dorsal horn.