EXPRESSION OF N-METHYL-D-ASPARTATE RECEPTOR SUBUNIT MESSENGER-RNAS INTHE HUMAN BRAIN - STRIATUM AND GLOBUS-PALLIDUS

N-methyl-D-aspartate receptors (NRs) play an important role in basal g anglia function. By using in situ hybridization with ribonucleotide pr obes, we investigated the regional and cellular distribution of NR sub unit mRNA expression in the human basal ganglia: caudate nucleus, puta men, lateral globus pallidus (LGP), and medial globus pallidus (MGP). Analysis of both film autoradiograms and emulsion-dipped slides reveal ed distinct distribution patterns for each subunit. On film autoradiog rams, the signal for NR1, NR2B, and NR2C in the striatum (STR) was hig her than in globus pallidus (GP). The NR2D probe gave a stronger signa l in GP than in STR. For NR2A we found a signal in all regions. Analys is of emulsion-dipped sections demonstrated that in striatal neurons, the NR2B signal was higher than in GP neurons. In GP neurons, NR2D was more abundant than in striatal neurons. Despite the relatively low si gnal on film for NR2C in GP, we found a slightly higher signal in GP p er neuron than in STR since in the pallidal areas neurons were sparse but intensely labeled. NR1 and NR2A were more evenly distributed over neurons of STR and GP. Between the different parts of STR and GP, we o bserved only minor differences in the expression of NRs. In MGP a subp opulation of neurons exhibiting low NR2D signals could be separated fr om the majority of neurons showing an intense NR2D signal. Since the p hysiological properties of NRs are dependent on subunit composition, t hese data suggest a high degree of regional specialization of NR prope rties in the human basal ganglia. (C) 1998 Wiley-Liss, Inc.