Hendry S H
Department of Anatomy and Neurobiology, University of California, Irvine 92717.
Exp Brain Res. 1991;86(1):47-59. doi: 10.1007/BF00231039.
GABA and glutamate decarboxylase (GAD) immunoreactivities were examined in dorsal lateral geniculate nuclei (LGN) of normal monkeys (Macaca fascicularis) and in monkeys that had one eye injected with tetrodotoxin (TTX) or one eye removed 5 days to 4 weeks prior to sacrifice. As seen in previous studies (Wong-Riley and Carroll 1984) monocular TTX injections or enucleation quickly reduced cytochrome oxidase (CO) staining in layers 2, 3 and 5 of the ipsilateral LGN and in layers 1, 4 and 6 of the contralateral LGN. The reduction in CO staining was apparent at all survival times examined. By contrast, GABA and GAD immunostaining in the LGNs were qualitatively normal up to two weeks following enucleation or after 17 days of TTX injections. Quantitative and stereological analyses confirmed that the numerical density and proportion of GABA and GAD neurons do not change in the LGN following two weeks of denervation or deprivation, even though in the same monkeys a reduction in GABA immunostaining was found in deprived-eye columns of area 17. However, with longer survivals, of 3-4 weeks in duration, the number of GABA and GAD immunostained neurons in the deprived/denervated-eye laminae of the LGN was reduced by one-third. These findings demonstrate that the deprivation-induced reduction in GABA and GAD immunoreactivity is delayed in the LGN, by comparison with the visual cortex, and suggest that the effects in the LGN may be relayed through the cortex or that neurotransmitter levels may be regulated by different mechanisms in the two sites.
在正常猕猴（食蟹猴）以及在处死前5天至4周单眼注射河豚毒素（TTX）或摘除单眼的猕猴的背外侧膝状核（LGN）中，检测了γ-氨基丁酸（GABA）和谷氨酸脱羧酶（GAD）免疫反应性。如先前研究（Wong-Riley和Carroll，1984年）所示，单眼注射TTX或摘除眼球后，同侧LGN的第2、3和5层以及对侧LGN的第1、4和6层的细胞色素氧化酶（CO）染色迅速减少。在所检测的所有存活时间点，CO染色的减少均很明显。相比之下，在摘除眼球后长达两周或TTX注射17天后，LGN中的GABA和GAD免疫染色在质量上是正常的。定量和体视学分析证实，去神经支配或剥夺两周后，LGN中GABA和GAD神经元的数量密度和比例没有变化，尽管在同一只猕猴的17区剥夺眼柱中发现GABA免疫染色减少。然而，在3 - 4周的较长存活期后，LGN中剥夺/去神经支配眼层中GABA和GAD免疫染色的神经元数量减少了三分之一。这些发现表明，与视觉皮层相比，LGN中剥夺诱导的GABA和GAD免疫反应性降低出现延迟，这表明LGN中的效应可能是通过皮层传递的，或者两个部位的神经递质水平可能由不同机制调节。
