Hayashi H
J Comp Neurol. 1985 Jul 8;237(2):195-215. doi: 10.1002/cne.902370205.
Horseradish peroxidase was intra-axonally injected into functionally identified primary afferent fibers within the rat spinal trigeminal tract in order to study the morphology of their central terminations. They were physiologically determined to be large, myelinated, cutaneous primary afferents by means of electrical and mechanical stimulation of their receptive fields. Ninety-three axons that innervated vibrissa follicles, guard hair follicles, and slowly adapting receptors were stained for distances of 4-12 mm at the levels of the main sensory nucleus, spinal trigeminal nucleus, and rostral cervical spinal cord. The collaterals of single axons from these receptors formed terminal arbors in the outer part of the spinal trigeminal nucleus rostral to and near the level of the obex (rostral type collaterals). In the rostral part of the subnucleus caudalis (Vc) they were confined to lamina V (caudalis type collaterals) and in the caudal part of Vc and in cervical segments they were confined to lamina III/IV (spinal-dorsal-horn-type collaterals). There were no transitional forms between the rostral and caudalis types, but there was a transitional form between the caudalis and spinal dorsal horn types. This transitional form was distributed in laminae III/IV and V. The terminal arbors of the rostral type of collaterals formed an interrupted, rostrocaudally oriented column like those seen in the lumbar dorsal horn, but the column shifted down to lamina V near the obex, and more caudally, gradually shifted upward to lamina III. Major morphological differences were not observed among the three different functional types of collaterals with respect to the rostrocaudal distribution of collaterals, and the shape and location of collaterals. The differential laminar distribution of collateral arbors of single axons along the rostrocaudal axis distinguishes the spinal trigeminal nucleus from the spinal dorsal horn where functional types of mechanoreceptive afferents form continuous or interrupted sagittal columns of terminal arbors that do not shift dorsoventrally within segments.
为了研究大鼠三叉神经脊髓束内功能确定的初级传入纤维的中枢终末形态，将辣根过氧化物酶注入其轴突内。通过对其感受野进行电刺激和机械刺激，从生理上确定它们为粗大的、有髓鞘的皮肤初级传入纤维。对支配触须毛囊、保护毛毛囊和慢适应感受器的93条轴突在主感觉核、三叉神经脊髓核和颈髓上段水平进行了4 - 12毫米距离的染色。来自这些感受器的单根轴突的侧支在闩平面上方和附近的三叉神经脊髓核外侧部形成终末分支（吻侧型侧支）。在尾侧亚核（Vc）的吻侧部分，它们局限于第V层（尾侧型侧支），在Vc的尾侧部分和颈段，它们局限于第III/IV层（脊髓背角型侧支）。吻侧型和尾侧型之间没有过渡形式，但尾侧型和脊髓背角型之间有过渡形式。这种过渡形式分布在第III/IV层和第V层。吻侧型侧支的终末分支形成一个中断的、沿吻尾方向排列的柱状结构，类似于在腰髓背角所见，但该柱状结构在闩附近向下移至第V层，更靠尾侧时逐渐向上移至第III层。在侧支的吻尾分布、侧支的形状和位置方面，未观察到三种不同功能类型侧支之间存在主要形态学差异。单根轴突侧支分支沿吻尾轴的不同分层分布，将三叉神经脊髓核与脊髓背角区分开来，在脊髓背角，机械感受器传入纤维的功能类型形成连续或中断的矢状终末分支柱，在节段内不会发生背腹移位。
