Verney C, Berger B, Adrien J, Vigny A, Gay M
Brain Res. 1982 Sep;281(1):41-52. doi: 10.1016/0165-3806(82)90111-0.
A precise topographical analysis of the distribution of tyrosine hydroxylase-like immunoreactive processes was performed in the frontal, cingular and parietal cortex of the rat during late embryonic and early postnatal life. Until birth, labeled processes were only observed in the restricted cortical areas known to receive a dopaminergic innervation in the adult brain. Their distribution differed markedly from that of noradrenergic fibers as identified by their dopamine-beta-hydroxylase-like immunoreactivity. Thus we considered TH-like immunoreactivity to be a selective marker of the cortical dopaminergic innervation during late fetal life, at least with the antibody we used. With this marker, dopaminergic fibers were first detected in the anterior frontal cortex at day 16 of embryonic life (E16). They developed as two bundles passing medially and laterally to the ventricular layer without penetrating it. From E20 on, the terminal fields extended to the cingular and rhinal cortex, still being restricted to the intermediate zone. No fibers were visible in the lateral and dorsal frontal cortex at this time, nor in the cortical plate and molecular layer in any cortical area. At E21, rare labeled fibers were seen in the molecular layer of the medial frontal and cingular cortex. After birth, the terminal fields of the TH-containing fibers extended further caudally in the cingular cortex and also superficially in the cortical plate. Moreover, labeled axons now also appeared in the lateral frontal and parietal cortex where their density gradually increased. At P14, two different patterns of distribution were observed: a high density of TH-positive fibers in the cortical areas known to receive a dopaminergic innervation; a low density of fibers in the other cortical areas which represented noradrenergic fibers. Indeed these TH-containing presumed noradrenergic fibers were absent at P14 following a bilateral destruction of the locus coeruleus in 4-day-old pups.
在胚胎后期和出生后早期，对大鼠额叶、扣带回和顶叶皮质中酪氨酸羟化酶样免疫反应阳性神经突起的分布进行了精确的局部分析。出生前，仅在成年大脑中已知接受多巴胺能神经支配的有限皮质区域观察到标记的神经突起。它们的分布与通过多巴胺-β-羟化酶样免疫反应鉴定的去甲肾上腺素能纤维的分布明显不同。因此，至少就我们使用的抗体而言，我们认为TH样免疫反应是胎儿后期皮质多巴胺能神经支配的选择性标记。使用该标记物，在胚胎期第16天（E16）首次在前额叶皮质中检测到多巴胺能纤维。它们发展为两束，向内侧和外侧穿过室管膜层但不穿透它。从E20开始，终末场扩展到扣带回和嗅皮质，仍局限于中间带。此时，在额叶外侧和背侧皮质中未见纤维，在任何皮质区域的皮质板和分子层中也未见纤维。在E21，在内侧额叶和扣带回皮质的分子层中可见罕见的标记纤维。出生后，含TH纤维的终末场在扣带回皮质中进一步向尾侧延伸，在皮质板中也向表面延伸。此外，标记的轴突现在也出现在额叶外侧和顶叶皮质，其密度逐渐增加。在P14时，观察到两种不同的分布模式：在已知接受多巴胺能神经支配的皮质区域中TH阳性纤维密度高；在其他代表去甲肾上腺素能纤维的皮质区域中纤维密度低。事实上，在4日龄幼崽双侧损毁蓝斑后，P14时这些含TH的假定去甲肾上腺素能纤维消失。
