Gordon B, Kinch G, Kato N, Keele C, Lissman T, Fu L N
Institute of Neuroscience, University of Oregon, Eugene 97403, USA.
J Comp Neurol. 1997 Jun 23;383(1):73-81. doi: 10.1002/(sici)1096-9861(19970623)383:1<73::aid-cne6>3.0.co;2-i.
We used quantitative autoradiography to determine whether the development of glutamate receptors correlates with the plastic period for monocular deprivation in rat visual cortex. To study glutamate receptors, we incubated sections of rat visual cortex with tritiated (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10imin e maleate (MK-801), tritiated kainate, and tritiated amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA). [3H]MK-801 is a noncompetitive ligand for the N-methyl-D-aspartate (NMDA) receptor. [3H]kainate and [3H]AMPA are competitive ligands for non-NMDA receptors. To compare glutamate binding sites with a nonglutamate binding site, we studied [3H]muscimol, which binds to gamma-aminobutyric acid (GABA)A receptors. [3H]MK-801 binding was maximal at postnatal day 26 (P26) and decreased in adulthood. [3H]AMPA binding was maximal at P18. [3H]kainate binding and [3H]muscimol binding were not age dependent. Dark rearing partially prevented the age-dependent decrease in [3H]MK-801 binding but had no effect on [3H]kainate or [3H]AMPA binding. Dark rearing decreased muscimol binding in adult animals. These results suggest that NMDA receptors, but not other glutamate receptors or GABAA receptors, are likely to be critical for developmental plasticity in rat visual cortex.
我们采用定量放射自显影术来确定谷氨酸受体的发育是否与大鼠视皮层单眼剥夺的可塑性时期相关。为研究谷氨酸受体，我们用氚标记的（+）-5-甲基-10,11-二氢-5H-二苯并[a,d]环庚烯-5,10-亚胺马来酸盐（MK-801）、氚标记的海人酸和氚标记的氨基-3-羟基-5-甲基异恶唑-4-丙酸（AMPA）孵育大鼠视皮层切片。[3H]MK-801是N-甲基-D-天冬氨酸（NMDA）受体的非竞争性配体。[3H]海人酸和[3H]AMPA是非NMDA受体的竞争性配体。为将谷氨酸结合位点与非谷氨酸结合位点进行比较，我们研究了[3H]蝇蕈醇，其与γ-氨基丁酸（GABA）A受体结合。[3H]MK-801结合在出生后第26天（P26）达到最大值，并在成年期下降。[3H]AMPA结合在P18时达到最大值。[3H]海人酸结合和[3H]蝇蕈醇结合不依赖年龄。暗饲养部分阻止了[3H]MK-801结合随年龄的下降，但对[3H]海人酸或[3H]AMPA结合没有影响。暗饲养降低了成年动物的蝇蕈醇结合。这些结果表明，NMDA受体而非其他谷氨酸受体或GABAA受体可能对大鼠视皮层的发育可塑性至关重要。
