单眼缝合、双眼缝合对猫视觉中枢中一氧化氮合酶阳性神经元数量与形态的影响

用ＮＡＤＰＨ－ｄ 组织化学方法观察了在生后一周内即施行单眼缝合和双眼缝合成活至１ 年的猫视觉中枢（上丘表层，外膝体和视皮层１７ 区）中的一氧化氮合酶阳性神经元数量及形态。结果显示：（１）单眼缝合或双眼缝合并不改变上丘表层中一氧化氮合酶阳性细胞的分布模式，也不影响该神经元的数量，但单眼缝合使对侧上丘表层一氧化氮合酶阳性神经元的树突野最大半径减小，树突总长度减少；而双眼缝合可使双侧上丘中一氧化氮合酶阳性细胞胞体减少，树突野最大半径以及树突总长度均明显减少。（２）单眼缝合导致外膝体非剥夺层中出现较多一氧化氮合酶阳性细胞，剥夺层少量出现，而双眼缝合却没有以上效应。（３）单眼缝合不影响视皮层１７ 区中一氧化氮合酶阳性细胞的空间分布模式以及该神经元在皮层各层中的分布密度；双眼缝合也不影响该神经元的分布模式，但可使ＮＡＤＰＨ－ｄ 黄递酶活性明显降低。提示视觉神经中枢中的一氧化氮合酶阳性神经元的活动受视网膜活动依赖性的调节，且受视觉经验的影响。

THE INFLUENCE OF REARING WITH MONOCULAR AND BINOCULAR LID SUTURE ON THE NUMBER AND MORPHOLOGY OF NOS POSITIVE NEURONS IN THE VISUAL CENTERS OF CATS

We investigated the changes in NADPH diaphorase staining that occurred in the visual centers of cats following monocular and binocular lid suture. This staining allows visualization of the synthesizing enzyme of nitric oxide, a neuromodulator associated with plasticity. Early monocular and binocular lid suture had no effect on the distribution pattern of NOS positive neurons in the superficial layers of superior colliculus (SC), but monocular lid suture resulted in the morphological changes of NOS positive neurons in contralateral SC and binocular lid suture induced morphological changes in bilateral SC, such as reductions of the maximum radius of dendritic field, total dendritic length and shrinkage of the soma size. Monocular lid suture induced the abnormal appearance of NOS positive neurons in lateral geniculate nucleus(LGN). These cells were located mainly in the nondeprived laminae, but binocular lid suture had no effect on NADPH diaphorase staining in LGN. Neither monocualr lid suture nor binocular lid suture could influence the distribution pattern of NOS positive neurons in the visual cortex but binocular lid suture induced reduction of NOS activity in all cortical layers. These results suggest that the NOS activity in visual centers is experience dependent. (Figures 1～13 on plate 56)