Apoptosis of neurons in the maturing neocortex has been recorded in a wide variety of mammals, but very little is known about its effects on cortical differentiation. Recent research has implicated the RhoA GTPase subfamily in the control of apoptosis in the developing nervous system and in other tissue types. Rho GTPases are important components of the signaling pathways linking extracellular signals to the cytoskeleton. To investigate the role of the RhoA GTPase subfamily in neocortical apoptosis and differentiation, we have engineered a mouse line in which a dominant-negative RhoA mutant (N19 -RhoA) is expressed from the Mapt locus, such that all neurons of the developing nervous system are expressing the N19 -RhoA inhibitor. Postnatal expression of N19 -RhoA led to no major changes in neocortical anatomy. Six layers of the neocortex developed and barrels (whisker-related neural modules) formed in layer IV. However, the density and absolute number of neurons in the somatosensory cortex increased by 12-26% compared with wild-type littermates. This was not explained by a change in the migration of neurons during the formation of cortical layers but rather by a large decrease in the amount of neuronal apoptosis at postnatal day 5, the developmental maximum of cortical apoptosis. In addition, overexpression of RhoA in cortical neurons was seen to cause high levels of apoptosis. These results demonstrate that RhoA-subfamily members play a major role in developmental apoptosis in postnatal neocortex of the mouse but that decreased apoptosis does not alter cortical cytoarchitecture and patterning.
The morphologic and morphometric features of the lower respiratory system in mole rats were examined. It was seen that the low respiratory system of this species leading a special life under highly hypoxic/hypercapnic conditions underground is structurally similar to other mammals living on land in terms of the parts examined; trachea was formed by 29.5 ± 4 oval-formed cartilaginous tracheals arranged backwards and became gradually more stenotic diameter from cranial to the caudal of the neck. The trachea was separated in two principal bronchus at the fourth thoracal intercostal spatium level. The angle between the two main principal bronchi was 60.5 ± 2.35°. The lung constituted 1.29 ± 0.03% of the body weight and the right lung was heavier than the left lung. Fissura inter-lobaris was deep and separated the lung lobes wholly, and the right lung was separated in four lobes, whereas the left lung was not separated into the lobes. Also, the medial lobe of the left lung was the lightest lobe.
This study was conducted to reveal the morphometric and morphological features of foot pads in the Anatolian bobcat (Lynx lynx). To achieve this objective, dissection, histological, and radiography techniques were applied to two dead materials obtained from the Republic of Turkey Ministry of Forest and Water Works Sivas Branch Manager. Digit I is radiographically rudimentary in the forepaw. The paws of the forelimb of the Anatolian bobcat have a carpal, a metacarpal, and four digital pads, while the hind feet have a metatarsal pad and four digital pads. The metacarpal pad is cone-like, while the metatarsal pad resembles a butterfly. The digital pads in the paws of the forelimb are longer and thinner than in the paws in the hind feet. The paws in both feet are situated as binary. Through histological examination, it was determined that the skin of the foot pads consists of epidermis, dermis, and pad cushion. The epidermis is subdivided into basal, spinous, granular, lucidum, and corneum layers. The dermis of each pad consists of papillar and reticular strata containing sweat glands, elastin, collagen, and reticular fibers. Anat Rec, 301:932-938, 2018. © 2017 Wiley Periodicals, Inc.
The histological and histochemical structure of lingual salivary glands in mole rat (Spalax leucodon) were studied using histochemical staining techniques to provide information of its salivary glands. A total of five adult mole rat (Spalax leucodon) were used as the material. It was observed that serous and mucous glands are placed in the root of the tongue. It was detected that although the mucous gland cells were rich in terms of AB pH 0.5, 1.0, 2.5 and AF (+) mucosubstance, the PAS and KOH/PAS mucosubstances showed very weak reaction, and this mucosubstances were present at a very less amount in serous gland cells. In the PAS/AB staining, it was found that the serous and mucous gland cells showing only AB or only PAS reaction and also AB AB pH 2.5 (+) cells were found. The same findings were observed in serous glands by AF/AB staining. Consequently, the present study demonstrated characteristic features of the lingual salivary glands of the mole rat, and it revealed histological and histochemical data both in accordance with and different from that for the lingual salivary glands of mammals and other species.
The distribution and relative frequency of external taste buds (TB) of Garra rufa were studied. TB of Garra rufa were observed on different body location (lips, lateral and ventral areas, forehead, operculum and dorsal-pelvic-pectoral-anal fins). TB are at the highest frequency in lips, forehead, pectoral and anal fins. These structures are moderate as a number in operculum, La2 (between pelvic and anal fins) areas, and then decreased a few in other areas.
We investigated carbohydrate residues on the epithelial surface, in the epithelial cells and in gland cells of the tongue of the mole rat using histochemical methods. We used horseradish peroxidase-conjugated lectins from Helix pomatia (HPA), Arachishypogaea (PNA), Ulexeuropaeus (UEA I), Canavaliaensiformis (Con A). The most intense reactivity was observed in the keratin layer with HPA, UEA I and Con A, and in the epithelial cells with UEA I and Con A. In the glands, we found strong reactivity in serous cells with HPA and Con A, and in mucous cells with HPA and UEA I. PNA did not bind to epithelial or gland cells. Consequently, GlcNAc, fucose and α-D-mannose terminal glycoconjugates are distributed widely; GalNAc terminal glycoconjugates appeared in small amounts.
Authors' Contribution RI and NK planned the research. FMG and RI wrote the article. FMG and FB performed the histological procedures and analysis.
The study was conducted for the determination of the main nerves of the lumbosacral plexus in the helmeted guineafowl. Five helmeted guineafowls were used. Fowls were anaesthetised and the a. carotis communis was cut for blood drainage. Body cavities were revealed and were fixated with 10% formaldehyde. Nerves forming the lumbosacral plexus were dissected and photographed. Results were named according to the Nomina Anatomica Avium. It was determined that the lumbosacral plexus forms by 8 synsacral ventral rami from the ventrolateral side of synsacrum which include (2–9) synsacral spinal nerves. It was seen that the lumbar plexus was formed by the ventral rami of the 2nd, 3rd and 4th spinal nerves, and the sacral plexus was formed by the ventral rami of the 5th, 6th, 7th, 8th and 9th synsacral spinal nerves. It was observed that following nerves of n. pubicus (ilioinguinalis), r. cutaneous femoris lateralis, r. cutaneous femoris medialis (n. saphenus), n. femoralis and n. obturatorius originate from the lumbar plexus, and following nerves of n. ischiadicus, the common branch of n. fibularis and n. tibialis originate from the sacral plexus. It was determined that the n. ischiadicus was formed by the truncus cranialis, medianus and caudalis. In conclusion, it was determined that there are macro anatomical differences between different avian species in the quantity, thickness and distribution of the spinal nerves that form the lumbosacral plexus, and in formations of the plexus, and in separations of nerve branches.
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