Higo S, Matsuyama T, Kawamura S
Department of Neuroscience and Immunology, Kumamoto University, Graduate School of Medical Sciences, Japan.
Neurosci Res. 1996 Oct;26(2):109-18. doi: 10.1016/s0168-0102(96)01079-6.
Direct projections from the pedunculopontine tegmental nucleus (PPT) and the laterodorsal tegmental nucleus (LDT) in the brainstem to area 17 of the visual cortex were investigated in the cat by the tract-tracing method with WGA-HRP. Neurochemical nature of neurons which were labeled retrogradely with WGA-HRP injected into area 17 was also examined immunohistochemically with antibodies against choline acetyltransferase (ChAT), tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH), and serotonin (5-HT). After injections of WGA-HRP into area 17, neurons in the caudal half of the PPT and the LDT were retrogradely labeled bilaterally with marked ipsilateral predominance. In the LDT, about 20% of the labeled neurons showed ChAT immunoreactivity (ChAT+); the vast majority (about 80%) of the labeled cells showed TH(+) and DBH(+). In the PPT, all retrogradely labeled cells exhibited TH(+) and DBH(+), but not ChAT(+). No retrogradely labeled cells with WGA-HRP showed 5-HT(+) in the PPT or LDT. The results indicate that the caudal part of the PPT and LDT sends projection fibers to area 17, and that PPT-neurons projecting to area 17 are noradrenergic, whereas LDT-neurons projecting to area 17 are cholinergic (20%) and noradrenergic (80%).
采用WGA-HRP示踪法，在猫脑内研究了脑干中脑桥脚被盖核（PPT）和外侧背盖核（LDT）向视皮层17区的直接投射。将WGA-HRP注入视皮层17区后，对逆行标记神经元的神经化学性质进行了免疫组织化学检测，所用抗体分别针对胆碱乙酰转移酶（ChAT）、酪氨酸羟化酶（TH）、多巴胺β羟化酶（DBH）和5-羟色胺（5-HT）。向视皮层17区注射WGA-HRP后，PPT和LDT尾侧部的神经元出现双侧逆行标记，以同侧为主。在LDT，约20%的标记神经元呈ChAT免疫反应阳性（ChAT+）；绝大多数（约80%）标记细胞呈TH（+）和DBH（+）。在PPT，所有逆行标记细胞均呈TH（+）和DBH（+），但无ChAT（+）。在PPT或LDT中，用WGA-HRP逆行标记的细胞均未显示5-HT（+）。结果表明，PPT和LDT的尾侧部向视皮层17区发出投射纤维，投射至视皮层17区的PPT神经元为去甲肾上腺素能神经元，而投射至视皮层17区的LDT神经元中20%为胆碱能神经元，80%为去甲肾上腺素能神经元。
