大鼠下丘脑到脊髓的直接纤维投射——WGA-HRP法研究

实验用28只170～285g SD大鼠。将WGA-HRP/HRP混合液注入颈、胸、腰及骶髓的一侧灰质。在下丘脑看到大量非均一性标记细胞。呈双侧分布,同侧较多;随着注射部位从头端向尾端移动,标记数量明显地递减。标记细胞以室旁核、下丘脑外侧区最为密集;视交叉后区、穹窿周核及未定带次之;下丘脑内侧区、室周核、背部下丘脑和后部下丘脑只有散在标记细胞;弓状核和视前区只有个别标记细胞。与文献相比,本实验表明,室旁核内的脊髓投射神经元并不局限于小细胞区,大细胞区也有较多分布;视上核和视交叉上核可能不直接投射到脊髓。

DIRECT PROJECTION FROM HYPOTHALAMUS TO SPINAl. CORD IN RATS

The present experiments were undertaken to localize the spinal projection neurons in different subdivisions of paraventrieular nucleus, and to test whether there exist spinal projection neurons in supraoptie nucleus as reported by Yang et al. WGA-HRP was injected into different spinal levels in 28 male SD rats, and the retrogradely labeled neurons in hypothalamus were examined under light microscope.A substantial number of retrogradely labeled neurons were visualized in hypothalamus, and the numbers of labeled neurons desereased progressively but the herterogenous labeled neurons in specific n clei or areas changed little with changing the WGA-HRP injection sites from cervical to sacral segments of spinal cord. Large numbers of labeled neurons were seen in paraventricular nucleus and lateral hypothalamic area; a lot of in retrochiasmatic area, perifornical nucleus and zona incerta; some in medial, dorsal and posterior hypothalamic areas; and a few in preoptic area and arcuate nucleus.In paraventricular nucleus a number of labeled neurons was found in ventral part of posterior magnocellular subdivision besides dorsal cap and lateral parvocellular subdivisions, and a few of labeled neurons were found in ventral part of medial parvocellular subdivision. No labeled neurons was found in supraoptic and suprachiasmatic unclei.