Toshitake Fujioka

The histochemistry of glycoconjugates in the colonic epithelium of the chicken

SummaryIn the colonic epithelium of the chicken, glycoconjugates have been studied by means of selected histochemical methods of light and electron microscopy. According to the results obtained, most of the colonic goblet cells contained acidic and neutral glycoconjugates with sulphate and vicinal diol groupings, α-D-mannose and α-D-glucose residues and sialic acid-galactose dimers. These goblet cells were found to undergo changes in histochemical reactivity during upward migration along the crypts; α-D-mannose and α-D-glucose residues and terminal sialic acidgalactose dimers increased in amount. The striated border of the colonic columnar cells has, likewise, been found to contain such glycoconjugates as were similar in reactivity to those of the goblet cells. The histophysiological significances of glycoconjugates involved in the chicken colonic epithelium have been discussed with special reference to the functional activities of the carbohydrates.

Projections of visceral and somatic primary afferents to the sacral spinal cord of the domestic fowl revealed by transganglionic transport of horseradish peroxidase.

The termination of visceral and somatic primary afferent fibers in the sacral spinal cord of the domestic fowl was studied using transganglionic transport of horseradish peroxidase. Nerve terminals of visceral afferent fibers were found in the lateral edge and base of the dorsal horn and in the dorsal gray commissure in close proximity to parasympathetic preganglionic neurons. Somatic afferents terminated in laminae 2 and 3. The results demonstrate that visceral and somatic afferent fibers in this avian species terminate in different areas of the dorsal horn.

Localization of the Motoneurons Innervating the Hindlimb Muscles in the Spinal Cord of the Domestic Fowl

The origins of the motor nerve fibers supplying the individual forelimb muscles were elucidated in the fowl by the retrograde degeneration method. Chromatolytic cells were seen in the ipsilateral lamina 9 of the cervical enlargement. Motoneurons innervating the individual forelimb muscles occupy the restricted area in the lamina 9. The muscles acting on the shoulder joint are supplied by motoneurons of the more cranial segments and the others acting on the elbow and the more distal joints by those of the more caudal ones. The origin of the dorsal cord is situated laterally in the lamina 9 and that of the ventral cord is located medially in it.

Intramitochondrial bodies in bovine adrenocortical cells

SummaryElectron dense, homogeneous, mostly round intramitochondrial bodies were found in bovine adrenal glands, predominantly in the zona glomerulosa. The histochemical results obtained suggest that these bodies might contain a considerable amount of protein, although the possibility that substances other than proteins are contained in these bodies cannot be completely ruled out. The physiological significance of the intramitochondrial bodies remains unclear.

Serotonin-storing cells of the chicken duodenum: light, fluorescence and electron microscopy, and immunohistochemistry

SummaryIn an attempt to identify duodenal endocrine cells emitting formaldehyde-induced fluorescence (FIF), chicken duodena were studied by combined fluorescence, ultrastructural, silver impregnation and immunohistochemical methods in the same or consecutive sections. Our results show that: (1) Almost all the cells emitting yellow fluorescence by both the Falck-Hillarp and the Furness methods exhibit an immunohistochemical reaction with serotonin (5-HT) antiserum. (2) Almost all cells radiating yellow fluorescence by the Furness method stain with toluidine blue in Epon-embedded sections but, by high-voltage electron microscopy, can be subdivided into two types of cell containing either small round or polymorphous types of granules. (3) In the sections from which resin had been removed, all the cells emitting yellow FIF show argentaffinity by the Singh method, but not all cells display argyrophilia with the Grimelius method. (4) Cells exhibiting both argyrophil and argentaffin reactions in deresined serial sections are also separated into two types of cell, containing either small spherical or polymorphous types of granules by conventional electron microscopy in thin sections. Therefore, chicken enterochromaffin cells emit yellow FIF, store 5-HT, show both argentaffinity and argyrophilia, but are ultrastructurally classified into two types of granule-containing cells which may be related to polypeptides coexisting with 5-HT.

Adrenocortical zonation of inbred wild-coloured mastomys, Praomys coucha: a new border zone in the cortex of females

Adrenal glands were examined in the inbred strain of wild-coloured mastomys (Praomys coucha), MWC. The most characteristic findings were emergence of a border zone between the zona fasciculata and z. reticularis of the cortex in females but not in males, and persistence of broad z. reticularis in males. The border zone was typically comprised of vacuolated cell layers, nodular layers and fibrous tissue. Vacuolated cells increased in number during pregnancy and partially disappeared during lactation. Growth of the nodules was greatly enhanced in both number and size during lactation. Thus, multiparae had very thick border zones composed predominantly of large nodules and, additionally, of vacuolated cells and fibrous tissue. The z. reticularis was compressed into a cord of closely packed cells by the expanded border zone in multiparous females but it continued to thicken with age in males. These changes produced completely different cortical zonation in the adrenal between sexes.

Catecholamine-containing neurons in the mesencephalic tegmentum of the chicken

SummaryThe nucleus tegmentalis dorsalis (NTD) which may be homologous with the mammalian locus coeruleus was investigated in the chicken by means of light, fluorescence and electron microscopy.Results are summarized as follows: 1) Numerous neurons emitting green fluorescence by the Falck-Hillarp method were observed in the NTD of the chicken. By consecutive light and fluorescence microscopy of the same section it was established that these catecholamine(CA)-containing neurons clearly coincided with the cell group named nucleus tegmentalis dorsalis by Jungherr (1945). This procedure further showed that there were also non-fluorescent neurons in the NTD. 2) On the basis of electron microscopic observation, two types of neurons were recognized in the NTD: medium-(15–25 μm) and small-sized (10–15 μm) neurons. Medium-sized neurons had a round to oval nucleus with several deep infoldings and abundant organelles. From combined fluorescence and electron microscopic examination, they obviously corresponded with CA-containing neurons demonstrated by the Falck-Hillarp method. Small-sized neurons had a round nucleus surrounded by pale cytoplasm. They corresponded with non-CA-containing neurons. 3) From morphometric analysis, it was clear that CA-containing neurons contained a well-developed rough-surfaced endoplasmic reticulum and many lysosome-like dense bodies, unlike non-CA-containing neurons.This study was undertaken as the basis of a research program to elucidate the catecholaminergic projections from the NTD.

Ultrastructural alterations of the pancreatic D cell in the domestic fowl following vagotomy

SummaryIn an attempt to determine the neural control of pancreatic D cells, the pancreatic islets of the domestic fowl were examined electron microscopically from 1 to 28 days after abdominal vagotomy. Exocytotic release of many secretory granules from D cells occurred one day after vagotomy. Rough endoplasmic reticulum developed and formed an arrangement of concentric whorls in the cytoplasm of D cells after axotomy. The altered D cells were also characterized by the occurrence of many peculiar dense bodies in the apical cytoplasm at all time periods studied. These bodies varied in shape and size, containing several round vesicles. The D cells were extensively depleted of granules after the longer time periods following vagotomy. The present results provide new morphological evidence for the vagus-nerve control of D cells, which may regulate the activity of islet cells.

Light and electron microscopic studies of intramitochondrial bodies in bovine adrenocortical cells by proteolytic digestion

SummaryThe nature of the intramitochondrial bodies in bovine adrenocortical cells was investigated both light and electron microscopically, by applying enzymatic digestion on paraffin and epon sections. The result that these bodies were extracted completely either by pepsin or by trypsin strengthened the validity of the previous conclusion that their nature is proteinaceous.

Effects of Lactation on the Border Zone Formation in the Female Mastomys (Praomys coucha) Adrenal Cortex

Adrenocortical zonation and especially border zone formation were investigated in relation to reproduction in female mastomys of the wild-colored inbred strain (MWC). The adrenal weight and the whole thickness of the cortex remained relatively constant throughout pregnancy, delivery and lactation. During pregnancy the zona fasciculata increased, but the z. reticularis decreased in thickness. The border zone between the z. fasciculata and the z. reticularis thickened 2-fold during pregnancy and further 2-fold during lactation. This zone was composed of vacuolated cell layers and nodules in females with a normal reproductive career. In young virgins this zone was barely identified by the presence of a few highly vacuolated cells. These cells became prominent during pregnancy and lactation. During lactation two types of cell aggregations, distinguishable by their stainability, vacuolation, localization and cellularity, appeared in the thickened border zone. The nodules first appeared within the z. reticularis after lactation. Neither thickening of both border zone and z. fasciculata nor formation of nodules occurred when lactation was interrupted after delivery. Thus, the changes in the female MWC adrenal, above all the appearance of nodules, seemed to be more dependent upon lactation than pregnancy. The vacuolated cells and the nodules might originate from the thickened z. fasciculata and the thinned z. reticularis, respectively, by the specific metamorphosis of the cells adjacent to the border zone. Their fusion and induction of fibrous tissue migration may result in the wider border zone.