Differential expression of AMPA glutamate receptor mRNAs in the rat adrenal gland.

Localisation of mRNA encoding the four AMPA glutamate receptor subunits in the rat adrenal gland was investigated using in situ hybridisation. GluR1 is found in the zona glomerulosa of the cortex, GluR3 in the remaining parts of the cortex, GluR2 in adrenal medullary cells and GluR4 at a very low level in the zona glomerulosa. All four receptor mRNAs are found in medullary ganglion cells. The flip form of GluR2 and GluR3 dominate and the GluR2 mRNA is present in the arginine encoding form. Different cell populations of the adrenal gland may express homomeric forms of different receptor subtypes.