抄録
Several morphological reports have been published, since the so-called “supramedullary nerve cell (SMC)” or “dorsale Zelle” was first discovered in the dorsal surface of the spinal cord in Cyclostomata by Owsjanikow (1854). However in the functional signification of the SMC, the opinions of authors have been incongruous, namely, Kapper et al. (1939), and Hughes (1957) presumed it to be a sensory nerve cell, while Bennett et al. (1959), Hagiwar aet al. (1959), and others denied this on the basis of their electrophysiological observations. While Ishibashi recently (1962) reported that the SMC was a sort of neurosecretory cells from the positive results of chrome-alum hematoxylin phloxine (CHP) staining preparations. Nakajima et al. (1965) are the first to study the SMC of the puffer by electron microscopy. Since they were unable to detect a correlation between SMC granules and elementary granules in the neurosecretory cells of the hypothalamus, they denied the theory of Ishibashi's, and concurrently reported the relationship between the SMC and the capillaries. We have studied the fine structure of the SMC of Spheroides Niphobles and compared our observations with those of the above-mentioned investigators.
