A developmental expression of AMPA-selective glutamate receptor subunits in human basal ganglia

The development of AMPA-selective glutamate receptors (GluR1 and GluR2-3) in human basal ganglia (BG) was investigated in 23 normal brains by means of an immunohistochemical method. Immunoreactivity to GluR1 and 2-3 was detected in the cytoplasm and dendrites of small and large neurons in the BG. GluR2-3 immunoreactivity-positive neurons were clearly observed at 23-24 gestational weeks (GW) in the globus pallidus and at 32 GW in the neostriatum, and reached a peak at 32 GW and 39 GW, respectively. GluR2-3 positive neurons in the BG began to decrease at 1-4 months of age, reaching the low level of adults by 7 months of age. The developmental pattern of GluR1 was similar to that of GluR2-3 in the BG, but the immunoreactivity to GluR1 was a little weaker than that of GluR2-3 in the neostriatum. Furthermore, GluR1 and 2-3 subunit Western blotting confirmed the specificity of the immunohistochemistry. Our results suggest that the development of GluR1 and 2-3 in the BG is consistent with neuronal development in the BG, which supports further that GluR1 and 2-3 play an important role in neuronal differentiation and maturation of the BG.