On vegetative nerve cells in human lumbar cord.

Abstract

Vegetative cells in lumbar cord. are much smaller than motor and sensory cells in it, poorer in nerve processes and stellar, triangular, spindle or club-shaped in form. Nerve fibrils in the cell body are also much less stainable and minuter than those in motor and sensory cells. The cell nucleus is, however, larger than in the motor and sensory cells, some times macro-sized. These vegetative cells with oversized cell nucleus were proved by Atsuki also in the Edinger-Westphal's nucleus, and are assumed to be parasympathetic in collation with experimental results. In accordance with him, I also assume that the cells with large cell nucleus are parasympathetic and the cells with smaller one are sympathetic in nature. In cornu laterale of the cranial lumbar cord, some larger vegetative cells are found, divided into lateral, medial and dorsal groups. The short processes of these cells are very short and small in number, ending sharply in most cases. I could not follow the course of the long processes to an adequate distance, but they may go over into radix ventralis, as assumed by Ziehen and Bok, for many minute vegetative fibres are found incorporated in radix ventralis. These cells are deemed sympathetic, as having a small cell nucleus each. There exist some vegetative cells corresponding to Bok's nucleus intermediomedialis in the medial side of pars intermedia of lumbar cord. They come to particularly strong development at the lumbar swelling, and can be divided into the ventral group consisting of larger cells and the medial and dorsal groups consisting of smaller cells. The cells in the former are stellar in shape and provided with macro-sized cell nucleus and can be clearly classified as parasympathetic cells, but those in the latter two have also a rather large cell nucleus each, so that they are also assumed to be parasympathetic in function. There are some vegetative cells arranged scattered in a band from the dorsomedial side of cornu ventrale to the commissura ventralis grisea, which seemingly correspond to the nucleus cornu commissuralis anterioris (Bok). The cells are small, with shape of elongated triangle or polygon, star or spindle, with their long axis and nerve processes parallel to that of the nucleus. These cells are provided with large cell nucleus and are apparently parasympathetic. But sometimes sympathetic cells with .smaller cell nucleus are also found coexistent with the parasympathetic. The Bok's nucleus cornu commissuralis posterioris is found diffused from the medial side of the head of cornu dorsale to the commissura dorsalis grisea, consisting of small-sized spindle-shaped parasympathetic cells with rather large cell nucleus. Their long axis and their generally bipolar processes are arranged parallel with the arcuate long axis of the nucleus. In the dorsal side of substantia grisea centralis are also found rather large stellar or polygonal cells grouped in several units. They are parasympathe-tic cells with large or macro-sized cell nucleus, and I propose to call their group nucleus dorsalis centralis. In the substantia gelatinosa and cornu dorsale are found scattered polygonal minute vegetative cells. Their cell nucleus is very large in proportion to the cell body. This cell group is thus presumed to be parasympathetic and seems to correspond to the nucleus parasympathicus of spinal cord as shown in the experimental study of Kure. He says that the long processes of these cells run to the periphery through the radix dorsalis, but I could not follow up their course satisfactorily. However, as many minute vegetative fibres are found running through the radix, I am not in the position to deny his assertion. Nucleus sympathicus mediosacralis, observed by Jacobsohn in the medial side of cornu ventrale of the 5th lumbar segment and downwards, is found in my specimens diffused as far as into the lumbar swelling.