Differential expression of AMPA receptor subunits in substance P receptor-containing neurons of the caudate-putamen of rats.
Previous evidence has suggested that glutamate-driving neurotransmission and glutamate-excitotoxicity are modulated by substance P in the basal ganglia, but the assembly of glutamate receptors mediating this process remains to be delineated. By using a double immunofluorescence, cellular expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor subunits (GluR1-4) in substance P receptor (SPR)-containing neurons was examined in the striatum of rats. It revealed that distribution of SPR-immunoreactive neurons completely overlapped with that of GluR1, 2, 3 or 4-immunoreactive neurons in the caudate-putamen. Neurons showing both SPR and AMPA receptor subunits (except of GluR3)-immunoreactivity were observed: all (100%) of SPR-positive neurons displayed GluR1-, GluR2- or GluR4-immunoreactivity, and the double-labeled neurons constituted about 33, 3 or 29% of total GluR-positive ones. In contrast, the neurons exhibiting both SPR- and GluR3-immunoreactivity were not detected, though numerous GluR3-positive neurons were still distributed in the caudate-putamen regions. Co-localization of SPR and distinct AMPA receptor subunits in the striatal neurons has provided a basis for functional modulation of neuronal APMA receptors by substance P in the caudate-putamen of rodents. Taken together with previous observations, this study has also suggested that, through interaction with AMPA receptors composed of subunits 1, 2 and 4, substance P or neurokinin peptides may play important roles in regulating neuronal properties and protecting neurons from excitotoxicity in the basal ganglia of mammals.
Hu
H-J
HJ
Institute of Neurosciences, The Fourth Military Medical University, Xi'an 710032, PR China.
Chen
L-W
LW
Yung
K K L
KK
Chan
Y S
YS
D000818:Animals; D002421:Caudate Nucleus / Q000166:cytology; D005786:Gene Expression Regulation / Q000502:physiology; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D017072:Neostriatum / Q000166:cytology* / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D011699:Putamen / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism*; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*
D021122:Protein Subunits; D018091:Receptors, AMPA; D018040:Receptors, Neurokinin-1