The adrenal gland is a vital endocrine gland that secretes many important hormones
in everyday bird life. The adrenal gland of the Japanese quail is grossly located ventromedially
the corresponding kidney and has a creamy to yellow color. The quail
gland is surrounded by a capsule and contains some ganglionic cells, and the capsule
is characterized by the presence of chromaffin cells. The adrenal gland is subdivided
into three concentric zones: subcapsular, peripheral, and central. The parenchyma
consists of interrenal tissue, chromaffin islets, and blood sinusoids. The interrenal
cells contain lipid droplets, are arranged in cords, and rest on the basement membrane.
Chromaffin cells are categorized as two types: epinephrine (E) and norepinephrine
(NE) cells. These cells contain the granules, and are characterized by the
presence of lipid droplets. In this study, the interrenal tissue was found to have a
higher proportion of chromaffin cells in quail as compared with other birds, which is
attributed to the fact that the Japanese quail is a migratory bird. Therefore, the present
investigation aims to provide a detailed study on the adrenal gland in the Japanese
quail to help physiologists understand the gland's function and the pathologist
to determine the implications for the differential diagnosis of adrenal gland tumors.

The retina consists of various cell types arranged in eight cell layers and two membranes
that originate from the neuroectodermal cells. In this study, the timing of differentiation
and distribution of the cellular components and the layers of the rabbit
retina are investigated using light and electron microscopy and immunohistochemical
techniques. There were 32 rabbit embryos and 12 rabbits used. The rabbit retina
begins its prenatal development on the 10th day of gestation in the form of optic
cup. The process of neuro- and gliogenesis occurs in several stages: In the first stage,
the ganglionic cells are differentiated at the 15th day. The second stage includes the
differentiation of Muller, amacrine, and cone cells on the 23rd day. The differentiation
of bipolar, horizontal, and rod cells and formation of the inner segments of the
photoreceptors consider the late stage that occurs by the 27th and 30th day of gestation.
On the first week of age postnatally, the outer segments of the photoreceptors
are developed. S100 protein is expressed by the Muller cells and its processes
that traverse the retina from the outer to the inner limiting membranes. Calretinin is
intensely labeled within the amacrine and displaced amacrine cells. Ganglionic cells
exhibited moderate immunoreactivity for calretinin confined to their cytoplasm and
dendrites. In conclusion, all stages of neuro- and gliogenesis of the rabbit retina occur
during the embryonic period. Then, the retina continues its development postnatally
by formation of the photoreceptor outer segments and all layers of the retina
become established.

The development of the cornea is a fascinating process. Its dual origin involves the
differentiation of surface ectoderm cells and the migration of mesenchymal cells of
neural crest origin. This research aimed to demonstrate the morphogenesis of the
rabbit cornea from fetal to postnatal life using light- and electron microscopy, and
immunohistochemical analysis. There were 27 rabbit embryos and nine rabbits used.
The rabbit cornea begins its prenatal development on the twelfth day of gestation.
The surface ectoderm differentiates into the corneal epithelium on day 13. Intriguingly,
telocytes were visible within the epithelium. The secondary stroma develops
on the sixteenth day of gestation by differentiation of keratocytes. At the age of
2 weeks, the lamellae of collagenous fibers become highly organized, and the stroma
becomes avascular, indicating that the cornea has become transparent. Bowman's
membrane appears on day 23 of pregnancy and disappears on day 30. The Descemet's
membrane appears at this time and continues to thicken postnatally. The corneal
endothelium appears on the twentieth gestational day as double layer of
flattened cells and becomes a single layer of cuboidal cells on day 30. The spaces
between the endothelial cells resemble craters. VEGF immunohistochemical expression
increases over the course of development, reaching its peak in the first week
after birth before decreasing in all corneal layers and becoming negative in the
stroma. In conclusion, numerous morphogenetic events contribute to corneal maturation
and transparency, allowing the cornea to perform its vital functions.

The adrenal glands are paired abdominal endocrine organs vital to the bird's health.
The present research aimed to provide a comprehensive examination of the histological, ultrastructural, and immunohistochemical investigations of the adrenal gland in
Japanese quail during the post hatching period. The current study was performed on
21 healthy Japanese quail chicks at different post hatching periods. Our results
showed the adrenal gland is surrounded by a connective tissue capsule, which consists of dense collagen fibers containing large blood vessels, chromaffin cells, autonomic ganglia, fibroblasts, and migrating Schwann cells. The zonation of the adrenal
gland is composed of a subcapsular layer, a peripheral zone, and a central zone, which
gets more pronounced with age. At the ultrastructural level, the interrenal cells take
the steroid-secreting cells characters; they have varying amounts of lipid droplets
and abundant mitochondria. Adrenal medullary chromaffin cells showed positive
immunoreactivity to the NSE. With increasing age, the chromaffin tissue's Sox10
immunoreactivity increased. β-catenin is expressed within the plasmalemma and the
cytoplasm of the interrenal and chromaffin cells and its reactivity increased with age,
especially in the chromaffin cells. Our results indicate the adrenal gland undergoes
significant morphological changes during the postnatal life. Overall, the postnatal
period is an important time for the development and maturation of the adrenal
glands.

https://analyticalsciencejournals.onlinelibrary.wiley.com/journal/10970029

The adrenal glands play a key role in maintaining the physiological balance of birds and
helping them to survive environmental changes. The objective of the present work was to
give a detailed investigation of the histological, ultrastructural, and immunohistochemical
findings of the adrenal gland in Japanese quail during the prehatching phase. The current
study was performed on 45 healthy Japanese quail embryos at different prehatching
periods. Our results showed the primordium of the quail's adrenocortical tissue appeared
at 3 days of incubation as a thickening of the splanchnic mesoderm. The prospective chromaffin cells appeared at 5 days as clusters of cells migrated from the neural crest cells
along the dorsal aorta toward the interrenal tissue. TH immunoreactivity was observed in
the neural crest cells during their migration toward the adrenal primordium. Furthermore,
these TH immunopositive cells were intermingled with the developing interrenal cell cords
that developed from the coelomic epithelium. NSE immunostaining was detected within
the cytoplasm of interrenal cells, chromaffin cells, and ganglion cells. Sox10 is expressed in
chromaffin and ganglion cells with different staining intensities. On the 13th day of prehatching, both interrenal and chromaffin cells were β-catenin immunonegative, but on the
17th day, both cells were immunopositively. Our findings show that during prenatal life,
the adrenal gland undergoes significant morphological changes. Together, the present data
suggest that studying the prenatal development of the adrenal gland in birds is important
for advancing our understanding of this critical organ and its functions.
 

https://analyticalsciencejournals.onlinelibrary.wiley.com/journal/10970029

Dramatic metabolic changes during pregnancy and post-partum period resulted in alteration of the biochemical parameters in dromedary she-camels. The current study focused on assessment of stress indicators in post-partum dromedary shecamels on days 14, 28 and 42 post-calving through monitoring the clinical findings, serum steroid hormones, serum or milk oxidant/antioxidant indicators, and milk somatic cell count (SCC) status with reference to serum lipid profile changes. The study also stated several correlations between reproductive cyclicity parameters, stress biomarkers and serum-milk oxidant/antioxidant indicators. The study was conducted on clinically healthy recently calved she-camels (n=25). They were subjected to clinical and laboratory assays including lipid profiles, serum steroid hormones [Progesterone (P4) and estradiol (E2)], serum or milk oxidant/antioxidant biomarkers [Malondialdehyde (MDA), reduced glutathione (GSH) and cortisol], and milk SCC on days 14, 21 and 28 post-calving. The study concluded the influence of stress as a result of lactation in post-partum period in recently calved she-camels and its relationship with reproductive cyclicity as well as changes in serum steroids, lipid profiles, serum-milk oxidant/antioxidants parameters, and milk SCC that was reflected through significant elevations in serum levels of P4, E2, cortisol, MDA and glucose, and milk values of MDA, cortisol and SCC as well as significant drop in serum levels of GSH, TPs, albumins and globulins on day 14 post-calving comparing with their values particularly on day 42. The study stated variable correlation relationships between reproductive cyclicity parameters, lipid profiles, serum-milk oxidant/antioxidants parameters and milk SCC.

The adrenal glands are paired abdominal endocrine organs vital to the bird's health.
The present research aimed to provide a comprehensive examination of the histological, ultrastructural, and immunohistochemical investigations of the adrenal gland in
Japanese quail during the post hatching period. The current study was performed on
21 healthy Japanese quail chicks at different post hatching periods. Our results
showed the adrenal gland is surrounded by a connective tissue capsule, which consists of dense collagen fibers containing large blood vessels, chromaffin cells, autonomic ganglia, fibroblasts, and migrating Schwann cells. The zonation of the adrenal
gland is composed of a subcapsular layer, a peripheral zone, and a central zone, which
gets more pronounced with age. At the ultrastructural level, the interrenal cells take
the steroid-secreting cells characters; they have varying amounts of lipid droplets
and abundant mitochondria. Adrenal medullary chromaffin cells showed positive
immunoreactivity to the NSE. With increasing age, the chromaffin tissue's Sox10
immunoreactivity increased. β-catenin is expressed within the plasmalemma and the
cytoplasm of the interrenal and chromaffin cells and its reactivity increased with age,
especially in the chromaffin cells. Our results indicate the adrenal gland undergoes
significant morphological changes during the postnatal life. Overall, the postnatal
period is an important time for the development and maturation of the adrenal
glands
 

Liver sinusoids are lined by fenestrated endothelial cells surrounded by perisinusoidal
cells, Kupffer cells, and pit cells, as well as large granular lymphocytes. The functional ability of
the liver cells can be substantially modified by exposure to toxins. In the current work, we assessed
the histopathological and ultrastructural effects of a time-course exposure to aflatoxin B1 (AFB1)
on the hepatic structures of rats. A total of 30 adult female Wistar rats were randomly divided
into three groups: a control group, a group orally administered 250 µg/kg body weight/day of
AFB1 for 5 days/week over 4 weeks, and a group that received the same AFB1 treatment but
over 8 weeks. Histopathological and ultrastructural examinations of hepatocytes revealed massive
vacuolar degeneration and signs of necrosis. Furthermore, the rat liver of the treated group exhibited
damage to the sinusoidal endothelium, invasion of the space of Disse with hyperactive Kupffer cells,
and some immune cells, as well as Ito cells overloaded with lipids. In addition, damaged telocytes
were observed. Taken together, our results indicate that AFB1 induces irreversible adverse effects on
the livers of rat