The present study examined changes in retinal tyrosine hydroxylase （TH） expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigat...The present study examined changes in retinal tyrosine hydroxylase （TH） expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigate the effects of amacrine cells on axonal regeneration in retinal ganglion cells and on the synapses that transmit visual signals. The results revealed that retinal TH expression gradually decreased following optic nerve transection in rats housed under a normal day/night cycle reaching a minimum at 5 days. In contrast, retinal TH expression decreased to a minimum at 1 day following optic nerve transection in dark reared rats, gradually increasing afterward and reaching a normal level at 5 7 days. The number of TH-positive synaptic particles correlated with the TH levels indicating that dark rearing can help maintain TH expression during the synaptic degeneration stage （5 7 days after optic nerve injury） in retinal amacrine cells.展开更多
Direction sensitivity is an important receptive property of visual cortical cells.On thesubcortical visual pathways,recent studies have shown that about 32% of LGNd relay cellsand 25% of retinal ganglion cells present...Direction sensitivity is an important receptive property of visual cortical cells.On thesubcortical visual pathways,recent studies have shown that about 32% of LGNd relay cellsand 25% of retinal ganglion cells presented direction sensitivity.This kind of directionsensitivity was also present in LGNd neurons of decorticate cats and dark-reared cats.Zhou et al.described two different types of direction sensitive cells in展开更多
基金supported by the National Natural Science Foundation of China (Influence of visual deprivation on bipolar cell synaptic formation and degeneration following opticnerve transection), No. 30671100
文摘The present study examined changes in retinal tyrosine hydroxylase （TH） expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigate the effects of amacrine cells on axonal regeneration in retinal ganglion cells and on the synapses that transmit visual signals. The results revealed that retinal TH expression gradually decreased following optic nerve transection in rats housed under a normal day/night cycle reaching a minimum at 5 days. In contrast, retinal TH expression decreased to a minimum at 1 day following optic nerve transection in dark reared rats, gradually increasing afterward and reaching a normal level at 5 7 days. The number of TH-positive synaptic particles correlated with the TH levels indicating that dark rearing can help maintain TH expression during the synaptic degeneration stage （5 7 days after optic nerve injury） in retinal amacrine cells.
基金supported by the National Natural Science Foundation of China, Chinese Academy of Sciences (CAS)the State. Science and Technology Commission of ChinaLaboratory for Visual Information Processing, Institute of Biophysics, CAS.
文摘Direction sensitivity is an important receptive property of visual cortical cells.On thesubcortical visual pathways,recent studies have shown that about 32% of LGNd relay cellsand 25% of retinal ganglion cells presented direction sensitivity.This kind of directionsensitivity was also present in LGNd neurons of decorticate cats and dark-reared cats.Zhou et al.described two different types of direction sensitive cells in
