ANALYSIS OF AMPA RECEPTOR SUBUNIT MESSENGER-RNA EXPRESSION IN CONTROLAND ALS SPINAL-CORD

THE distribution of glutamate receptor subunits in human spinal cord h as yet to be fully elucidated. The aim of this study was to examine th e distribution of mRNAs for the subunits of the AMPA type of glutamate receptor (GluR A, B, C and D) in control human spinal cord using in s itu hybridization and to examine in parallel the expression of these m RNAs in patients with sporadic amyotrophic lateral sclerosis (ALS). We also quantitated mRNA levels for these subunits in spinal cord homoge nates. The relative abundances of the receptor subunits were as follow s: GluR A > GluR B > GluR D > GluR C with A, B and D expressed in foci corresponding to the medial, lateral and ventral clusters of motor ne urones. Quantitation of homogenates revealed a significant decrease (3 8%) in GluR A mRNA in ALS spinal cord compared with controls, and a 67 % decrease of GluR B mRNA compared with controls. Levels of GluR C and D were too low to analyse densitometrically.