STRATIFICATION OF ON AND OFF GANGLION-CELL DENDRITES DEPENDS ON GLUTAMATE-MEDIATED AFFERENT ACTIVITY IN THE DEVELOPING RETINA
STRATIFICATION OF ON AND OFF GANGLION-CELL DENDRITES DEPENDS ON GLUTAMATE-MEDIATED AFFERENT ACTIVITY IN THE DEVELOPING RETINA
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DOI：
10.1038/364144a0
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发表时间：
1993-07-08
期刊：
影响因子：
64.8
通讯作者：
CHALUPA, LM
中科院分区：
文献类型：
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作者：
BODNARENKO, SR;CHALUPA, LM
脊椎动物视觉系统的一个基本属性是ON和OFF通路的分离，信号光的增加和减少1 -4。在成熟的视网膜中，ON-和OFF-中心视网膜神经节细胞（RGC）的树突在内丛状层（IPL）的不同亚层中分层，并且由两种类型的双极细胞不同地支配，所述双极细胞在暴露于光时去极化和过度极化5 -10。ON和OFF RGC的这种分层是通过逐渐限制其树突来实现的，树突在发育早期在整个IPL中分叉11 -14。造成这种倒退的因素尚不清楚。树突状分层发生在双极细胞在IPL中形成突触的时间附近15，16，这提高了突触活动参与该过程的可能性。在这里，我们通过用谷氨酸类似物2-氨基-4-膦酰基丁酸（APB）治疗发育中的猫视网膜来测试这一假设，该谷氨酸类似物使ON锥双极和杆双极细胞超极化，从而防止它们释放谷氨酸17 -19。我们报告说，眼内注射APB在此期间，树突状分层正常发生防止结构隔离的ON和OFF视网膜通路的形成。这些结果提供的证据表明，谷氨酸介导的传入活动调节发育过程中的RGC树突的重塑。
A FUNDAMENTAL attribute of the vertebrate visual system is the segregation of ON and OFF pathways signalling increments and decrements of light1-4. In the mature retina, dendrites of ON- and OFF-centre retinal ganglion cells (RGCs) stratify in different sublaminae of the inner plexiform layer (IPL), and are differentially innervated by two types of bipolar cells which depolarize and hyperpolarize on exposure to light5-10. This stratification of ON and OFF RGCs is achieved by the gradual restriction of their dendrites which ramify throughout the IPL early in development11-14. The factors underlying this regressive event are unknown. Dendritic stratification occurs around the time that bipolar cells form synapses in the IPL15,16, which raises the possibility that synaptic activity is involved in this process. Here we test this hypothesis by treating the developing cat retina with the glutamate analogue 2-amino-4-phosphonobutyric acid (APB), which hyperpolarizes ON cone bipolar and rod bipolar cells, thereby preventing their release of glutamate17-19. We report that intraocular injection of APB during the period when dendritic stratification normally occurs prevents the formation of structurally segregated ON and OFF retinal pathways. These results provide evidence that glutamate-mediated afferent activity regulates the remodelling of RGC dendrites during development.