Neuroanatomical studies on the development of the primary facial taste center in fish

点击翻译按钮获取中文摘要

This study was undertaken to reveal the developmental process of the structures of FL in the sea catfish and carp using general morphological and Antibromodeoyuridine (BrdU) immunohistochemistry methods.Sea catfish : At 5 days of post hatch(P5d) the FL is found as an anterior portion of the longitudinal column. Barbel lobules were first observed at P6d. At P12d, trunk lobule appeared laterodorsal to the other lobules. At P26d, the four barbel lobules occupied the anterior half of the FL, indicating that the relative growth of the lobules was greater than that of the other part of the FL.Cell divisions were observed in the mediodorsal margin of the FL and continued up to 25 days after hatching. At P4-6d cell divisions were observed only in the mediodorsal margin of the FL anteroposteriorly. When the lobules became distinct, cell divisions were distributed not only in the medial margin but also along the entire border of the anterior portion of the FL.Cell divisions became more active in the anterior direction. The anterior extension of the FL is caused by the anterior movement of the germinal zone. The newly formed cells migrated toward the center of the FL at each level of FL rather than in posteroanterior direction.Carp : At P8d the FL was detected as a paired massive structure in the medulla and hereafter grew up to dorsad and mediad. At p10-12d The FLs began to fuse medially and this fusion was completed at P13-15d. BrdU experiments demonstrated the presence of cell division in the medial and dorsal surface of the FLs. As the day passed, the germinal layr was limited in the mediodorsal surface of the FL.The cell divisions were greatest in number at P14-20d and observed up to P50d. The last cell divisions were mainly found in the dorsomedial portion of the caudal FL.The early cells moved to the ventral portion and the last cells formed the dorsal portion of the FL.