Sánchez-Camacho C, Marín O, López J M, Moreno N, Smeets W J A J, ten Donkelaar H J, González A
Departamento de Biología Celular, Facultad de Biología, Universidad Complutense of Madrid, Madrid, Spain.
Brain Res Bull. 2002;57(3-4):325-30. doi: 10.1016/s0361-9230(01)00671-2.
The origin and development of the supraspinal catecholaminergic (CA) innervation of the spinal cord was studied in representative species of the three amphibian orders (Anura: Xenopus laevis and Rana perezi; Urodela: Pleurodeles waltl; Gymnophiona: Dermophis mexicanus). Using retrograde dextran amine tracing in combination with tyrosine hydroxylase (TH)-immunohistochemistry, we showed that only four brain centers contribute to the CA innervation of the adult spinal cord: (1) the ventrolateral component of the posterior tubercle, (2) the periventricular nucleus of the zona incerta, (3) the locus coeruleus, and (4) the nucleus of the solitary tract (except for gymnophionans). The pattern observed is largely similar in all amphibian species studied. The development of the CA innervation of the spinal cord was studied with in vitro double labeling methods in Xenopus laevis tadpoles. At stage 40/41, the first CA neurons projecting to the spinal cord were found to originate in the posterior tubercle. At stage 43, spinal projections were found from the periventricular nucleus of the zona incerta and the locus coeruleus, whereas spinal projections from the nucleus of the solitary tract were not observed before stage 53. These results demonstrate a temporal sequence in the appearance of the CA cell groups projecting to the anuran spinal cord, organized along a rostrocaudal gradient.
在两栖纲三个目（无尾目：非洲爪蟾和泽陆蛙；有尾目：肋突螈；蚓螈目：墨西哥蚓螈）的代表性物种中，研究了脊髓的脊髓上儿茶酚胺能（CA）神经支配的起源和发育。通过逆行葡聚糖胺追踪结合酪氨酸羟化酶（TH）免疫组织化学，我们发现只有四个脑区对成年脊髓的CA神经支配有贡献：（1）后结节的腹外侧部分，（2）未定带的室周核，（3）蓝斑，以及（4）孤束核（蚓螈目除外）。在所研究的所有两栖类物种中观察到的模式基本相似。在非洲爪蟾蝌蚪中，采用体外双重标记方法研究了脊髓CA神经支配的发育。在第40/41阶段，发现第一批投射到脊髓的CA神经元起源于后结节。在第43阶段，发现有来自未定带室周核和蓝斑的脊髓投射，而在第53阶段之前未观察到来自孤束核的脊髓投射。这些结果证明了投射到无尾目脊髓的CA细胞群出现的时间顺序，是沿头尾梯度组织的。
