Browsing by Subject "Cerebral cortex"
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- PublicationOpen AccessChanges in the brain cortex of rabbits on a cholesterol-rich diet following supplementation with a herbal extract of Tribulus terrestris(Murcia : F. Hernández, 2009) Berkman, Zafer; Tanriover, Gamze; Acar, Goksemin; Sati, Leyla; Altug, Tuncay; Demir, RamazanExtracts of the medicinal herb Tribulus terrestris (TT) are used for treating various diseases. The saponins, a component of TT, play a role in regulating blood pressure and in treatment of hyperlipidemia. The aim of the study was to investigate the immunohistochemical and ultrastructural alterations in the cerebral cortex of experimental rabbits on a cholesterol rich diet treated with TT. The rabbits were divided into three groups and followed for 12 weeks as control group (CG); experimental group I (EG-I), fed with a cholesterol-rich diet; experimental group II (EG-II), treated with an extract of TT (5mg/kg/day) after a cholesterol-rich diet of 4 weeks. In EG-I there were ultrastructural changes, including mitochondrial degeneration, increased lipofuscin pigments, myelin sheath damage with axoplasmic shrinkage and electron dense granules in the neurovascular unit. The number of synapses apparently decreased in both experimental groups. Administration of TT extract in EG-II led to marked ultrastructural alterations in neurons, including decreased mitochondrial degeneration (P<0.001) and extensive oedematous areas in the neurovascular unit. However, in EG-II, lamellar myelin, axonal structures and mitochondria were well protected. These alterations possibly indicate that saponins have an effect on the neurons either directly or by its conversion to steroidal saponins. Therefore, these findings add further evidence supporting the protective claims of TT in cerebral architecture in dietary induced hyperlipidemia.
- PublicationOpen AccessDistribution of Kiaa0319-like immunoreactivity in the adult mouse brain - a novel protein encoded by the putative dyslexia susceptibility gene KIAA0319-like(Editores F. Hernandez y Juan F. Madrid. Murcia, Universidad de Murcia, Departamento de Biologia Celular e Histologia, 2011) Poon, Ming-Wai; Tsang, Wan-Hong; Waye, Miu-Yee; Chan, Sun-OnKiaa0319L is a novel protein encoded by a recently discovered gene KIAA0319-like(L) that may be associated with reading disability. Little is known about the characteristics of this protein and its distribution in the brain. We investigated here expression of this protein in adult mice, using an antibody specific for human and rodent Kiaa0319L. In the brain, Kiaa0319L was localized strongly in the olfactory bulb, and strong expression was found in other regions, including hippocampus, cerebellum, diencephalon and the cerebral cortex. Immunohistochemistry confirmed expression in these brain regions, and showed further that the protein was expressed preferentially in neurons in layer IV and VI of the neocortex, CA1 and CA2 subfields of the hippocampus and a subpopulation of neurons in CA3 and dentate gyrus. Furthermore, the protein was confined to dendrites of CA1 neurons in the stratum radiatum, but not those in the stratum oriens, and in astrocytes within the hippocampus. In the cerebellum, the protein was observed in the molecular layer and a fraction of Purkinje neurons. These findings confirmed expression of Kiaa0319L in brain regions that are involved in reading performance, supporting its possible involvement in reading disability. The specific patterns of localization in the neocortex, hippocampus and cerebellum suggest further that this protein may be related to other biological processes in a subpopulation of neurons within these regions, eg. formation and maintenance of polarity in the neuron.
- PublicationOpen AccessLesion and regeneration in the medical cerebral cortex of lizards(Murcia : F. Hernández, 1992) López-García, Carlos; Molowny, A.; Martínez Guijarro, F.J.; Blasco-lbáñez, J.M.; Luis de la Iglesia, J.A.; Bernabeu, A.; García-Verdugo, J.M.The cerebral cortex of Squamate reptiles (lizards and snakes) may be regarded as an archicortex or ereptilian hippocampus». In lizards, one cortical area, the media1 cortex, may be considered as a true ~fascia dentata» on grounds of its anatomy, connectivity and cyto- chemo-architectonics of its main zinc-rich axonal projection. Moreover, its late ontogenesis and postnatal development support this view. In normal conditions, it shows delayed postnatal neurogenesis and growth during the lizard's life span. Remnant neuroblasts in the media1 cortical ependyma of adult lizards seasonally proliferate. The late-produced immature neurocytes migrate to the medial cortex cell layer where they differentiate and give off zinc-containing axons directed to the rest of cortical areas. This results in a continuous growth of the medial cortex and its zinc-rich axonal projection. Perhaps the most important characteristic of the lizard medial cortex is that it can regenerate after having been almost completely destroyed. Recent experiments in our laboratory have shown that chemical lesion of its neurons (up to 95%) results in a cascade of events; first, those related with massive neuronal death and axonal-dendritic retraction and, secondly, those related with a triggered neuroblast proliferation and subsequent neohistogenesis, and the regeneration of an almost new medial cortex that shows itself undistinguishable from a normal undamaged one. This is the only report to our knowledge that an arnniote central nervous centre may regenerate by new neuron production and neo-histogenesis. Perhaps the media1 cortex of lizards may be used as a model for neuronal regeneration andlor transplant experiments in mammals or even in primates.
- PublicationOpen AccessPersistence of Cajal-Retzius cells in the adult human cerebral cortex. An immunohistochemical study(Murcia : F. Hernández, 1999) Martí, R.; Gutierrez, A. ,; Peñafiel, A.; Marin-Padilla, M.; De la Calle, A.The presence of Cajal-Retzius cells in the adult human prefrontal and visual cortices has been demonstrated with calcium binding protein immunocytochemistry and NADPH-diaphorase histochemistry. These cells expressed parvalbumin, calbindin and calretinin calcium binding proteins and displayed NADPH-diaphorase enzyme activity. The three basic morphological profiles-horizontal, pyriform and multipolar-were observed. The morphologies of labelled cells resembled those of neurons observed in Golgi studies of the human cerebral cortex. The presence of calcium binding proteins and NADPH-diaphorase in these cells suggests a possible inhibitory role as GABAergic neurons. The persistence of Cajal-Retzius cells in the adult cerebral cortex supports the idea that they undergo developmental dilution rather than postnatal degeneration.
- PublicationEmbargoWidespread doublecortin expression in the cerebral cortex of the octodon degus(Frontiers Media, 2021-04-29) Van Groen, Thomas; Kadish, Inga; Caballero Bleda, María; Baño-Otalora, Beatriz; Rol, María Ángeles; Madrid, Juan Antonio; Popovic, Natalija; Popovic Popovic, Miroljub; Anatomía Humana y PsicobiologíaIt has been demonstrated that in adulthood rodents show newly born neurons in the subgranular layer (SGL) of the dentate gyrus (DG), and in the subventricular zone (SVZ). The neurons generated in the SVZ migrate through the rostral migratory stream (RMS) to the olfactory bulb. One of the markers of newly generated neurons is doublecortin (DCX). The degu similarly shows significant numbers of DCX-labeled neurons in the SGL, SVZ, and RMS. Further, most of the nuclei of these DCX-expressing neurons are also labeled by proliferating nuclear antigen (PCNA) and Ki67. Finally, whereas in rats and mice DCX-labeled neurons are predominantly present in the SGL and SVZ, with only a few DCX neurons present in piriform cortex, the degu also shows significant numbers of DCX expressing neurons in areas outside of SVZ, DG, and PC. Many areas of neocortex in degu demonstrate DCX-labeled neurons in layer II, and most of these neurons are found in the limbic cortices. The DCX-labeled cells do not stain with NeuN, indicating they are immature neurons.
- PublicationOpen AccessWidespread doublecortin expression in the cerebral cortex of the Octodon degus(Frontiers Media, 2021-04-29) Groen, Thomas van; Kadish, Inga; Caballero Bleda, María; Baño Otalora, Beatriz; Rol de Lama, María de los Ángeles; Madrid, Juan Antonio; Popovic, Natalija; Popovic Popovic, Miroljub; FisiologíaIt has been demonstrated that in adulthood rodents show newly born neurons in the subgranular layer (SGL) of the dentate gyrus (DG), and in the subventricular zone (SVZ). The neurons generated in the SVZ migrate through the rostral migratory stream (RMS) to the olfactory bulb. One of the markers of newly generated neurons is doublecortin (DCX). The degu similarly shows significant numbers of DCX-labeled neurons in the SGL, SVZ, and RMS. Further, most of the nuclei of these DCX-expressing neurons are also labeled by proliferating nuclear antigen (PCNA) and Ki67. Finally, whereas in rats and mice DCX-labeled neurons are predominantly present in the SGL and SVZ, with only a few DCX neurons present in piriform cortex, the degu also shows significant numbers of DCX expressing neurons in areas outside of SVZ, DG, and PC. Many areas of neocortex in degu demonstrate DCX-labeled neurons in layer II, and most of these neurons are found in the limbic cortices. The DCX-labeled cells do not stain with NeuN, indicating they are immature neurons.