TY - JOUR
T1 - Fimbria-fornix transections selectively down-regulate subtypes of glutamate transporter and glutamate receptor proteins in septum and hippocampus
AU - Ginsberg, Stephen D.
AU - Rothstein, Jeffrey D.
AU - Price, Donald L.
AU - Martin, Lee J.
PY - 1996/9
Y1 - 1996/9
N2 - The effects of CNS axotomy on glutamate transporter and glutamate receptor expression were evaluated in adult rats following unilateral fimbria-fornix transections. The septum and hippocampus were collected at 3, 7, 14, and 30 days postlesion. Homogenates were immunoblotted by using antibodies directed against glutamate transporters (GLT-1, GLAST, and EAAC1) and glutamate receptors (GluR1, GluR2/3, GluR6/7, and NMDAR1), and they were assayed for glutamate transport by D-[3H]aspartate binding. GLT-1 was decreased at 7 and 14 days postlesion within the ipsilateral septum and at 7 days postlesion in the hippocampus. GLAST was decreased within the ipsilateral septum and hippocampus at 7 and 14 days postlesion. No postlesion alterations in EAAC1 immunoreactivity were observed. D[3H]Aspartate binding was decreased at 7, 14, and 30 days postlesion within the ipsilateral septum and 14 days postlesion in the hippocampus. GluR2/3 expression was down- regulated at 30 days postlesion within the ipsilateral septum, whereas GluR1, GluR6/7, and NMDAR1 immunoreactivity was unchanged. In addition, no alterations in glutamate receptor expression were detected within hippocampal homogenates. This study demonstrates a selective down-regulation of primarily glial, and not neuronal, glutamate transporters and a delayed, subtype- specific down-regulation of septal GluR2/3 receptor expression after regional deafferentation within the CNS.
AB - The effects of CNS axotomy on glutamate transporter and glutamate receptor expression were evaluated in adult rats following unilateral fimbria-fornix transections. The septum and hippocampus were collected at 3, 7, 14, and 30 days postlesion. Homogenates were immunoblotted by using antibodies directed against glutamate transporters (GLT-1, GLAST, and EAAC1) and glutamate receptors (GluR1, GluR2/3, GluR6/7, and NMDAR1), and they were assayed for glutamate transport by D-[3H]aspartate binding. GLT-1 was decreased at 7 and 14 days postlesion within the ipsilateral septum and at 7 days postlesion in the hippocampus. GLAST was decreased within the ipsilateral septum and hippocampus at 7 and 14 days postlesion. No postlesion alterations in EAAC1 immunoreactivity were observed. D[3H]Aspartate binding was decreased at 7, 14, and 30 days postlesion within the ipsilateral septum and 14 days postlesion in the hippocampus. GluR2/3 expression was down- regulated at 30 days postlesion within the ipsilateral septum, whereas GluR1, GluR6/7, and NMDAR1 immunoreactivity was unchanged. In addition, no alterations in glutamate receptor expression were detected within hippocampal homogenates. This study demonstrates a selective down-regulation of primarily glial, and not neuronal, glutamate transporters and a delayed, subtype- specific down-regulation of septal GluR2/3 receptor expression after regional deafferentation within the CNS.
KW - Axotomy
KW - Fimbria - fornix
KW - Glutamate receptor
KW - Glutamate transporter
KW - Hippocampus
KW - Septum
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U2 - 10.1046/j.1471-4159.1996.67031208.x
DO - 10.1046/j.1471-4159.1996.67031208.x
M3 - Article
C2 - 8752128
AN - SCOPUS:0029795954
SN - 0022-3042
VL - 67
SP - 1208
EP - 1216
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
IS - 3
ER -