猫颈髓内长下行脊髓固有束神经元的定位研究

LOCALIZATION OF THE LONG DESCENDING PROPRIOSPINAL TRACT(LDPT) NEURONS OF CERVICAL SPINAL CORD IN CAT

用HRP逆标方法和荧光染料碘化丙啶(PI)逆行标记与单胺荧光组织化学相结合的方法发现,大多数被HRP标记的长下行脊髓固有束(LDPT)神经元出现于颈膨大Ⅶ和Ⅷ层,少数在Ⅰ、Ⅴ和Ⅹ层。同侧的神经元多半分布于Ⅶ层,小部分在Ⅷ层,少数在Ⅰ和Ⅴ层内,对侧的此神经元,绝大多数在Ⅷ层内,少数在Ⅶ层内,少数几个位于Ⅹ层。此结果进一步证实了同侧和对侧LDPT神经元在颈膨大内各有特有的分布。在朡髓(T_(8-11))的Ⅹ区,也观察到少数HRP标记的下行脊髓同有束神经元,这些神经元胞体在水平切片上面积很大(50—60μm)。此外,在LDPT神经元和下行的单胺能末梢之间联系的观察中,一些呈绿荧光的NA能末梢与LDPT神经元树突和胞体有紧密接触。表明下行的NA能末梢可能和LDPT神经元有直接联系。

The methods of retrograde transport of HRP and fluorescent dye propidium iodide. (PI) retrograde labelling in. combination with monoamine fluorescence histochemistry were used in the present work. Most LDPT neurons labeled by HRP were found in Rexed laminae Ⅶ and Ⅷ of the cervical enlargement, a few of them within laminae Ⅰ、Ⅴ and Ⅹ. Ipsilateral LDPT neurons were distributed mainly in lamina Ⅶ, less within lamina Ⅷ, and least in laminae Ⅰ and Ⅴ. The majority of contralateral LDPT neurons were distributed in lamina Ⅷ, the minority of them within lamina Ⅶ and a few of them in lamina Ⅹ. In the present work, it was found for the first time that the large LDPT neurons also were present within lamina Ⅹ of thoracic segments (T_(8-12)), The horizontal section areas of cell bodies were very large (50-60μm in diameter). Besides, in the study of connections of LDPT neurons with descending monoaminergic terminals, it was found that the greenish noradrenergic(NA) terminals were seen very close to dendrites or soma of the LDPT neurons labeled by PI. The results indicate that the descending NA terminals might be in direct contact with the LDPT neurons.