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The vomeronasal organ (VNO), because of its ability to detect pheromones, has an important role in many social and sexual behaviours in mammals. It also mediates defensive behaviours through detection of protein pheromone homologues. A detailed morphological description of the post-natal development of the 'non-sensory' epithelium (NSE) of the female rabbit is recorded. Histological techniques were used to study the NSE of the VNO in post-natal development of female rabbits. The study focused on the following post-natal ages: newborn, 1 week, 2 weeks and 1 month (five animals each) beside to two adult animals. The rabbit VNO was surrounded externally by bony capsule and internally by cartilaginous capsule. NSE was pseudostratified columnar partially ciliated epithelium without goblet cells. In addition to basal cells, NSE contained ciliated and three types of non-ciliated columnar cells (dark, pale and light). At birth, dark cells may have primary cilia. By 1 month, the cytoplasm became lighter with less free ribosomes. The pale cells had electron-lucent cytoplasm, which contained a few organelles. Mitotic figures were observed in basal and columnar cells, particularly during the first 2 weeks of post-natal development. Light columnar cells were common during the first week. Numerous leucocytes and a few nerve endings were detected intra-epithelial. Scanning electron microscope revealed a gradual increase in height of microvilli of non-ciliated cells. Ciliated cells had cilia and microvilli. Cells were arranged singly, in clumps or in a dense population of cells. The rabbit VNO-NSE had a unique morphological structure.

Epilepsy is one of the most common neurological disorders, its prevalence approximately from 0.5% to 2% of the general population. Generalized seizures could lead to several morphological changes in the brain. This study aimed to investigate the morphological effects of a single convulsive dose of pentylenetetrazol (PTZ) on rat dentate gyrus at different postnatal ages. Thirty-six male Wistar rats were used at the following postnatal ages: P10, P21, and P90 (12 rats per each age). The animals in each age were equally divided into two groups: group I, control and group II, treated with a single intraperitoneal injection of PTZ (55 mg/kg). After confirmation of generalized tonic-clonic seizures, specimens from the right dentate gyrus were processed for light and electron microscopy. In PTZ-treated groups, the number of granule cells significantly decreased. Dark granule cells appeared in the deep layers of the granule cells in P10 and with the progress of age, they significantly increased in number and extended into the superficial layers of the granule cells. The dendritic spines diminished. Glial fibrillary acidic protein and caspase-3 expression increased. Ultrastructurally, granule cells showed irregular shaped nucleus, dilated rough endoplasmic reticulum (RER) cisternae, mitochondria with damaged cristae, large vacuoles, lysosomes, and lipofuscin granules. Dark granule cells characterized by electron-dense nucleus and cytoplasm containing disorganized Golgi bodies, swollen mitochondria with damaged cristae, numerous free ribosomes and few long strands of RER. Astrocytes had hypertrophied cell body. Acute treatment with PTZ-induced epileptic seizures caused toxic effect on the structure of rat dentate gyrus at different postnatal ages.

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All-trans Retinoic acid (atRA) is instructive for the development of endocrine pancreas and is an integral component of b-cell induction protocols. We showed that atRA induces glucose-responsive endocrine transdifferentiation of pleomorphic pancreatic ductal adenocarcinoma cells in vitro. This study aimed to detect the role of atRA in improving the histological changes of the pancreas in diabetic rats. Forty young male Wistar rats were used and divided into three groups. Group I: normal vehicle control (N 5 5). Group II: streptozotocin-induced diabetic rats (N 5 20) were followed up at 0.0, 1, 2, and 4 weeks. Group III: streptozotocininduced diabetic rats (N 5 15) treated with atRA (2.5 mg/kg/day), were followed up at 1, 2, and 4 weeks. Specimens from the pancreas were processed for light, electron microscopy and pancreatic insulin mRNA expression. Blood samples were assayed for the levels of glucose, insulin, and total peroxides. In the atRA-treated group, the number of the islets and the islet area significantly increased. Strong insulin-immunoreactive endocrine-like cells were observed nearby the pancreatic acini and the interlobular ducts. Interestingly, insulin-positive cells seemed to arise from pancreatic acinar and ductal epithelium. Ultrastructurally, ß-cells, acinar, and ductal cells restored their normal appearance. Pancreatic insulin mRNA and blood indices were almost normalized. AtRA improved the histological changes of the pancreas and the blood indices in diabetic rats. Anat Rec, 299:334-351, 2016. V C 2015 Wiley Periodicals, Inc.