以CB-HRP标记支配大鼠坐骨海绵体肌、球海绵体肌和胸乳突肌的神经元及其树突

Localization of Motoneurons Innervating M. Ischiocavernosus, M. Bulbocavernosus and M. Sternocleidomastoideus in Rat with Their Dendritic Distribution Revealed by CB-HRP

给成年雄鼠的坐骨海绵体肌,球海绵体肌注射酶标类霍乱原,在腰骶段脊髓灰质可标出三组神经元:背内侧组(DM)、腹组(V)及腹外侧组(VL)。各组神经元树突通过不同途径抵达软脊膜下,DM组神经元树突可达室管膜下。给雄鼠胸乳突肌注射CB-HRP,在颈髓标出:背内侧组(DM)、腹组(V)及位于Rexed第X板层(或Rexed第Ⅶ板层最内侧)的背内侧背组(RDM)三组神经元。RDM组的发现为胸乳突肌的特殊内脏运动的本质提供了新证据.DM组神经元树突可达软膜下和室管膜下,RDM神经元树突可达室管膜下。上述软膜下及室管膜下树突的存在,反映了中枢运动神经元“旁侧回路”存在的普遍性。

Injections of CB-HRP (conjugates of horseradish percxidase with cho-leragen subunit B) into M. bulbocavernosus and M. ischiocavernosus of male adult rat, both produce labelling of three groups of motoneurons in lumbosacral cord. They are dorsorredial (DM), vcntral(V) and ventro-lateral (VL) . The dendrites of these three groups of neurons can all reach subpial region of anterior funiculus and that of the DM reach even subependymal region. Injection into M. sternocleidomastoideus produces labelling of three groups of neurons aswell in the cervical cord. They are DM. V and RDM. The latter localizes in the grey matter of Rexed lamina X or most medial part of Rexed lamina VII. The dendrites of DM neurons can resch subpial region of anterior funiculus and subependymal region, while that of RDM can reach subependymal region only. The results are summarized as follows:1) the existence of Golgi-phobic dendrites (GBD) , including marginal and subependymal dendrites with the help of CB-HRP is extensive in spinal motoneurons; 2) the RDM group of neurons revealed after injection of CB-HRP into M .sternoclei domasto ideus in rat is new evidence of special viseral motor nature of that mus-de; and 3) there are also dendrites perforating anterior median fissure.