Miguel-Hidalgo J J, Senba E, Takatsuji K, Tohyama M
Department of Anatomy II, Osaka University Medical School, Japan.
Neuroscience. 1991;44(1):235-43. doi: 10.1016/0306-4522(91)90264-o.
We have previously shown that retinal deafferentation causes a decrease in immunoreactive dendrites of substance P-positive neurons of the superficial superior colliculus of the rat. Since some retinorecipient thalamic and pretectal nuclei are putative targets for substance P-containing cells of the superior colliculus, the present study attempted to ascertain whether substance P-immunoreactive fibers in these nuclei are also affected by retinal denervation. We found that unilateral eye removal produced a progressive increase in fibrous substance P immunoreactivity in the nucleus of the optic tract, lateral posterior nucleus, and lateral geniculate nucleus of the side contralateral to the enucleation. On the other hand, unilateral lesions to the superficial layers of the superior colliculus produced a dramatic reduction in substance P immunoreactivity in the ipsilateral nucleus of the optic tract, lateral posterior nucleus, and dorsal and ventral lateral geniculate nuclei. In bilaterally enucleated animals, unilateral lesion to the superior colliculus produced, as expected, loss of immunoreactive fibers only in the lateral posterior nucleus and the retinorecipient nuclei ipsilateral to the lesion. These results suggest that transneuronal changes in the distribution of substance P in collicular neurons observed after enucleation could be reflected in their projections to the other primary visual centers and to the lateral posterior nucleus.
我们之前已经表明，视网膜去传入会导致大鼠上丘浅层P物质阳性神经元的免疫反应性树突减少。由于一些接受视网膜传入的丘脑和顶盖前核是上丘含P物质细胞的假定靶点，本研究试图确定这些核中的P物质免疫反应性纤维是否也受视网膜去神经支配的影响。我们发现，单侧眼球摘除会使摘除眼球对侧的视束核、外侧后核和外侧膝状核中的纤维性P物质免疫反应性逐渐增加。另一方面，对上丘浅层进行单侧损伤会使同侧视束核、外侧后核以及背侧和腹侧外侧膝状核中的P物质免疫反应性显著降低。在双侧摘除眼球的动物中，如上所述，对上丘进行单侧损伤仅会导致损伤同侧的外侧后核和接受视网膜传入的核中免疫反应性纤维丧失。这些结果表明，摘除眼球后观察到的上丘神经元中P物质分布的跨神经元变化可能反映在它们向其他主要视觉中枢和外侧后核的投射中。
