Heterogeneity of AMPA receptors in the dorsal column nuclei of the rat.

We have combined immunocytochemistry with retrograde tracing to demonstrate that projecting neurons in the gracile and cuneate nuclei express predominantly the GluR3 subunit of the AMPA receptor while interneurons in these nuclei express predominantly the GluR1 subunit. Interneurons expressing the GluR2 subunit are also present. It is speculated that the two classes of interneurons may release different inhibitory transmitters.