Muir-Robinson Gianna, Hwang Bryan J, Feller Marla B
Neurobiology Section, Biology Division, University of California San Diego, La Jolla, California 92093, USA.
J Neurosci. 2002 Jul 1;22(13):5259-64. doi: 10.1523/JNEUROSCI.22-13-05259.2002.
Spontaneous retinal activity mediated by cholinergic transmission regulates the segregation of retinal ganglion cell axons in the lateral geniculate nucleus of the thalamus into eye-specific layers. The details of how the layers form are unknown. Mice lacking the beta2 subunit of the neuronal nicotinic acetylcholine receptor lack ACh-mediated waves and as a result, do not form eye-specific layers at any stage of development. However, during the second postnatal week, beta2-/- mice have glutamate-mediated waves. Here we show that after the first postnatal week, even in the absence of layers, retinothalamic axons segregate into an unlayered, patchy distribution of eye-specific regions. These results indicate that spontaneous neural activity may independently regulate eye-specific segregation and the formation of layers at the developing retinothalamic projection.
由胆碱能传递介导的视网膜自发活动调节视网膜神经节细胞轴突在丘脑外侧膝状核中向眼特异性层的分离。这些层如何形成的细节尚不清楚。缺乏神经元烟碱型乙酰胆碱受体β2亚基的小鼠缺乏乙酰胆碱介导的波，因此在发育的任何阶段都不会形成眼特异性层。然而，在出生后第二周，β2基因敲除小鼠有谷氨酸介导的波。我们在此表明，在出生后第一周之后，即使没有层，视网膜丘脑轴突也会分离成眼特异性区域的无层、斑片状分布。这些结果表明，自发神经活动可能在发育中的视网膜丘脑投射中独立调节眼特异性分离和层的形成。
