Tan M M, Harvey A R
Department of Anatomy and Human Biology, University of Western Australia, Nedlands, Perth.
Neuroscience. 1989;32(2):511-20. doi: 10.1016/0306-4522(89)90098-5.
The distribution of choline acetyltransferase was determined in normal and transplanted rat superior colliculus with choline acetyltransferase immunohistochemistry. This distribution was compared to the pattern of histochemically detected acetylcholinesterase activity. To determine cholinergic input to the superficial superior colliculus, double labelling experiments combining retrograde tracing methods and choline acetyltransferase immunohistochemistry were carried out. No choline acetyltransferase-containing neurons were observed in the rat superior colliculus. A dense network of choline acetyltransferase-immunoreactive fibres and terminals was seen in the intermediate layers of the normal superior colliculus. The distribution was patchy and very similar to the pattern of acetylcholinesterase activity. Occasional fibres and terminals were seen in the deep tectal laminae. The superficial layers contained a low number of choline acetyltransferase-stained fibres and terminals but a comparatively high level of acetylcholinesterase activity. Following a unilateral injection of a tracer into the superficial superior colliculus, retrogradely labelled choline acetyltransferase-immunoreactive neurons were found in the dorsal and ventral subnuclei of the ipsilateral parabigeminal nucleus. As in the normal superior colliculus, choline acetyltransferase-positive neurons were not found in tectal transplants. However, choline acetyltransferase-immunoreactive fibres and terminals were seen in grafts but only in those which had extensive connections with the host midbrain. The pattern of staining most closely resembled that seen in the intermediate layers of the normal superior colliculus. The similar arrangement of choline acetyltransferase and acetylcholinesterase activity in the intermediate layers of normal rat superior colliculus provides further evidence for cholinergic innervation to these layers, probably originating in the dorsal and pedunculopontine tegmental nuclei. The data from the double labelling experiments indicate that the choline acetyltransferase-immunoreactive terminals observed in the superficial layers represent the terminal field of an ipsilateral cholinergic projection from the parabigeminal nucleus. Tectal grafts receive cholinergic innervation from the host. The evidence suggests that much of this input derives from the cholinergic nuclei in the brainstem tegmentum which normally project to the intermediate tectal layers.
采用胆碱乙酰转移酶免疫组织化学方法，测定正常大鼠和移植大鼠上丘中胆碱乙酰转移酶的分布。将该分布与组织化学检测的乙酰胆碱酯酶活性模式进行比较。为了确定向浅层上丘的胆碱能输入，进行了结合逆行追踪方法和胆碱乙酰转移酶免疫组织化学的双重标记实验。在大鼠上丘中未观察到含胆碱乙酰转移酶的神经元。在正常上丘的中间层可见密集的胆碱乙酰转移酶免疫反应性纤维和终末网络。其分布呈斑片状，与乙酰胆碱酯酶活性模式非常相似。在深层顶盖板中可见偶尔的纤维和终末。浅层含有少量胆碱乙酰转移酶染色的纤维和终末，但乙酰胆碱酯酶活性水平相对较高。在向浅层上丘单侧注射示踪剂后，在同侧副视束核的背侧和腹侧亚核中发现了逆行标记的胆碱乙酰转移酶免疫反应性神经元。与正常上丘一样，在顶盖移植中未发现胆碱乙酰转移酶阳性神经元。然而，在移植物中可见胆碱乙酰转移酶免疫反应性纤维和终末，但仅在那些与宿主中脑有广泛连接的移植物中可见。染色模式与正常上丘中间层所见最为相似。正常大鼠上丘中间层胆碱乙酰转移酶和乙酰胆碱酯酶活性的相似排列为这些层的胆碱能神经支配提供了进一步证据，可能起源于背侧和脚桥被盖核。双重标记实验的数据表明，在浅层观察到的胆碱乙酰转移酶免疫反应性终末代表来自副视束核的同侧胆碱能投射的终末场。顶盖移植物接受来自宿主的胆碱能神经支配。证据表明，这种输入的大部分来自脑干被盖中的胆碱能核，这些核通常投射到顶盖中间层。
