Tian N, Copenhagen D R
Department of Ophthalmology, UCSF School of Medicine, San Francisco, CA 94143, USA.
Neuron. 2001 Nov 8;32(3):439-49. doi: 10.1016/s0896-6273(01)00470-6.
Visual deprivation impedes refinement of neuronal function in higher visual centers of mammals. It is often assumed that visual deprivation has minimal effect, if any, on neuronal function in retina. Here we report that dark rearing reduces the light-evoked responsiveness of inner retinal neurons in young mice. We also find that 1 to 2 weeks after eye opening, there is a surge (>4-fold) in the frequency of spontaneous excitatory and inhibitory synaptic events in ganglion cells. Dark rearing reversibly suppresses this surge, but recovery takes >6 days. Frequency changes are not accompanied by amplitude changes, indicating that synaptic reorganization is likely to be presynaptic. These findings indicate there is a degree of activity-dependent plasticity in the mammalian retina that has not been previously described.
视觉剥夺会阻碍哺乳动物高级视觉中枢神经元功能的精细化。人们通常认为，视觉剥夺对视网膜神经元功能即便有影响，也是微乎其微的。在此我们报告，在幼鼠中，暗饲养会降低视网膜内层神经元的光诱发反应性。我们还发现，在睁眼后1至2周，神经节细胞中自发兴奋性和抑制性突触事件的频率会激增（超过4倍）。暗饲养会可逆性地抑制这种激增，但恢复需要超过6天的时间。频率变化并未伴随幅度变化，这表明突触重组可能发生在突触前。这些发现表明，哺乳动物视网膜中存在一定程度的活动依赖性可塑性，这在之前并未被描述过。
