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Unlike mammals, species such as fish and amphibians can regenerate damaged spinal cords, offering insights into potential therapeutic targets. This study investigates the structural features of the molly fish spinal cord through light and electron microscopy. The most notable characteristic was the presence of Mauthner cells (M‐cells), which exhibited large cell bodies and processes, as well as synaptic connections with astrocytes. These astrocytic connections contained synaptic vesicles, suggesting electrical transmission at the M‐cell endings. Astrocytes, which were labeled with glial fibrillary acidic protein (GFAP), contained cytoplasmic glycogen granules, potentially serving as an emergency fuel source. Two types of oligodendrocytes were identified: a small, dark cell and a larger, lighter cell, both of which reacted strongly with oligodendrocyte transcription factor 2 (Olig2). The dark oligodendrocyte resembled human oligodendrocyte precursors, while the light oligodendrocyte was similar to mature human oligodendrocytes. Additionally, proliferative neurons in the substantia grisea centralis expressed myostatin, Nrf2, and Sox9. Collectively, these findings suggest that the molly fish spinal cord has advanced structural features conducive to spinal cord regeneration and could serve as an excellent model for studying central nervous system regeneration. Further studies on the functional aspects of the molly fish spinal cord are recommended. Research Highlights: Mauthner cells (M‐cell), with their typical large cell body and processes, were the most characteristic feature in Molly fish spinal cord, where it presented synaptic connections with astrocytes and their ends contained synaptic vesicles indicating an electrical transmission in the M‐cells endings.Two types of oligodendrocytes could be recognized; both reacted intensely with Oligodendrocyte transcription factor 2 (Olig2).The proliferative neurons of the substantia grisea centralis expressed myostatin, Nrf2, and Sox9.The findings of this study suggest that molly fish possess highly developed structural features conducive to spinal cord regeneration. Consequently, they could be deemed an exemplary model for investigating central nervous system regeneration. [ABSTRACT FROM AUTHOR]

The ultimobranchial gland of the mulard duck is a bilateral endocrine organ that is located in the thorax. The current study aimed to describe the topographical, anatomical and histological picture of the ultimobranchial gland in mulard ducks. Eleven healthy adult males of ducks were selected. Gross morphology and histological analysis of ultimobranchial tissue was performed. Grossly, ultimobranchial glands appeared yellow spherical bodies on both sides of the trachea near the syrinx, parallel to the common carotid arteries and cranio-lateral to the junction of the subclavian and common carotid arteries. Each ultimobranchial gland composed of two lobes adhered to each other and appeared as a single gland. Histologically, Ultimobrachial gland had a delicate connective tissue capsule around the gland that composed mainly of Collagenous fibers. The main cells of the glands were parafollicular or C cells which supported by connective tissue stroma. C cells having columnar shapes with centrally located oval nucleus. They were organize in many clusters of various sizes and also single C-cells were present scattered throughout the stroma of the gland. The C cells showed on reaction with PAS stain, whereas the connective tissue stroma and capsule were reacted positively with PAS stain. This study characterized ultimobranchial gland location, gross anatomy and microscopic features in mulard ducks. [ABSTRACT FROM AUTHOR]

The thyroid gland of the Mulard duck and turkey is a bilateral endocrine organ that is located in the thorax. The current study aimed to describe the topographical, anatomical and histological picture of the thyroid gland in ducks and turkeys. Eeighteen healthy adult males of ducks and Egyptian turkeys were selected. Gross morphology and histological analysis of thyroid tissue was performed. Grossly, thyroid glands appeared dark red oval bodies near the carotid artery. Histologically, glands contained thousands of follicles within a collagenous capsule. Follicle shapes ranged from spherical to elliptical. In ducks, follicular epithelium was squamous to cuboidal. In turkeys, epithelium was cuboidal to columnar based on activity. Colloid stained strongly positive in duck follicles but moderately to weakly in turkeys on PAS reaction. Connective tissue and follicular lining showed weak PAS positivity in both species. This study characterized thyroid gland location, gross anatomy and microscopic features in ducks and turkeys. Histological analysis revealed inter-species similarities and differences at the tissue and cellular level. [ABSTRACT FROM AUTHOR]

The present study aimed to provide a detailed description of the normal development of rabbit stomach and focusing on the histogenesis of gastric glands. In a total, 24 New Zealand White rabbit fetuses were collected at gestational days 21, 25, and 29. The stomachs of the collected fetuses were fixed in 10% neutral buffered formalin and prepared by paraffin technique then stained with Harris's Haematoxylin and Eosin, Masson's Trichrome stain, Orcein, Periodic acid-Schiff, Alcian blue, and Bromophenol blue stains. The results revealed that, at 21stgestational day, the different parts of the stomach including, cardia, fundus and pylorus could be easily distinguished. On 25th developmental day, the gastric mucosal folds were more prominent in the cardia than fundus and pylorus. At 29th developmental day, tunica mucosa and tunica submucosa of the fetal stomach were laid in longitudinally oriented folds known as rugae. The gastric gland in this age became well developed containing welldemarcated oxyntic and peptic cells. In conclusion, the rabbit stomach is completely differentiated during the embryonic life and the gastric glands were functionally active. [ABSTRACT FROM AUTHOR]