[Organization of the life-ensuring systems of spinal cord nerve cells in dogs].

By means of Klosovsky's impregnation method and injecting the vascular network with gelatin--indian ink solution with a subsequent additional staining of the cells after Nissl's method, interposition of neural cells of IX and VI laminae with the vessels and glia has been studied in the dog spinal cord at the level of L6. Sources of blood inflow and outflow from motoneurons and intercalated cells, average density of the capillary network, length of the capillary bed surrounding each cell have been defined; means of interaction of the neural cells with the surrounding capillaries has been estimated; diameter and length of the loop formed have been measured. The number of glia per 1 mm3 of the medullary tissue has been counted. Comparing the results of the investigation obtained, it has been stated that the function of the neural cell in the spinal cord determines certain peculiarities of its feeding systems. The motoneuron has a more adequate vascular ensurence than the intercalated cells of VI lamina. Getting blood from greater number of sources, the motoneuron possesses also some direct ways of the arterial inflow and a quick elimination of metabolic products. In spite of the fact that the vascular-capillary network in IX lamina is less dense, the proper microcirculatory bed of the motoneuron is developed much better. The number of cells being in contact with the capillaries and the length of the contacting surfaces in the motoneuron prevail over those in the posterior horn neurons. At the same time, the number of glial cells in VI lamina is greater than those in the inferior horns. A suggestion is made that the cells of this lamina get their feeding mediated via glia.