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Glycine receptor‐mediated synaptic transmission regulates the maturation of ganglion cell synaptic connectivity
Author(s) -
Xu HongPing,
Tian Ning
Publication year - 2008
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.21727
Subject(s) - neuroscience , biology , neurotransmission , inner plexiform layer , glycine receptor , retina , synapse , retinal ganglion cell , receptor , glycine , genetics , amino acid
It is well documented that neuronal activity is required for the developmental segregation of retinal ganglion cell (RGC) synaptic connectivity with ON and OFF bipolar cells in mammalian retina. Our recent study showed that light deprivation preferentially blocked the developmental RGC dendritic redistribution from the center to sublamina a of the inner plexiform layer (IPL). To determine whether OFF signals in visual stimulation are required for OFF RGC dendritic development, the light‐evoked responses and dendritic stratification patterns of RGCs in Spastic mutant mice, in which the OFF signal transmission in the rod pathway is largely blocked due to a reduction of glycine receptor (GlyR) expression, were quantitatively studied at different ages and rearing conditions. The dendritic distribution in the IPL of these mice was indistinguishable from wildtype controls at the age of postnatal day (P)12. However, the adult Spastic mutants had altered RGC light‐evoked synaptic inputs from ON and OFF pathways, which could not be mimicked by pharmacologically blocking of glycinergic synaptic transmission on age‐matched wildtype animals. Spastic mutation also blocked the developmental redistribution of RGC dendrites from the center to sublamina a of the IPL, which mimicked the effects induced by light deprivation on wildtype animals. Moreover, light deprivation of the Spastic mutants had no additional impact on the RGC dendritic distribution and light response patterns. We interpret these results as that visual stimulation regulates the maturation of RGC synaptic activity and connectivity primarily through GlyR‐mediated synaptic transmission. J. Comp. Neurol. 509:53–71, 2008. © 2008 Wiley‐Liss, Inc.