bluuebunny/crossref_metadata_2025_split huggingface dataset:
Opposing Roles of Cholinergic and GABAergic Activity in the Insular Cortex and Nucleus Basalis Magnocellularis during Novel Recognition and Familiar Taste Memory Retrieval
Authors: Rodríguez-García Gabriela , Miranda María Isabel 
Published: February 2016

Acetylcholine (ACh) is thought to facilitate cortical plasticity during memory formation and its release is regulated by the nucleus basalis magnocellularis (NBM). Questions remain regarding which neuronal circuits and neurotransmitters trigger activation or suppression of cortical cholinergic activity. During novel, but not familiar, taste consumption, there is a significant increase in ACh release in the insular cortex (IC), a highly relevant structure for taste learning. Here, we evaluate how GABA inhibition modulates cholinergic transmission and its involvement during taste novelty processing and familiar taste memory retrieval. Using saccharin as a taste stimulus in a taste preference paradigm, we examined the effects of injecting the GABAAreceptor agonist muscimol or the GABAAreceptor antagonist bicuculline into the IC or NBM during learning or retrieval of an appetitive taste memory on taste preference in male Sprague Dawley rats. GABAAreceptor agonism and antagonism had opposite effects on cortical ACh levels in novel taste presentation versus familiar taste recognition and ACh levels were associated with the propensity to acquire or retrieve a taste memory. These results indicate that the pattern of cortical cholinergic and GABAergic neuroactivity during novel taste exposure is the opposite of that which occurs during familiar taste recognition and these differing neurotransmitter system states may enable different behavioral consequences. Divergences in ACh and GABA levels may produce differential alterations in excitatory and inhibitory neural processes within the cortex during acquisition and retrieval.SIGNIFICANCE STATEMENTDuring learning and recall, several brain structures act together. This work demonstrates interactions between cortical cholinergic and GABAergic systems during taste learning and memory retrieval. We found that the neuroactivity pattern during novel taste exposure is opposite that which occurs during familiar taste recognition. GABAAreceptors must be inactive during novel tasting to enable new memory formation, but must be active and inhibiting acetylcholine release in the cortex to allow memory retrieval. These findings indicate that GABA inhibition modulates cholinergic transmission and that cholinergic–GABAergic system interactions are important during the transition from novel to familiar memory.
QRFP and Its Receptors Regulate Locomotor Activity and Sleep in Zebrafish
Authors: Chen Audrey , Chiu Cindy N. , Mosser Eric A. , Khan Sohini , Spence Rory , Prober David A. 
Published: February 2016

The hypothalamus plays an important role in regulating sleep, but few hypothalamic sleep-promoting signaling pathways have been identified. Here we demonstrate a role for the neuropeptide QRFP (also known as P518 and 26RFa) and its receptors in regulating sleep in zebrafish, a diurnal vertebrate. We show that QRFP is expressed in ∼10 hypothalamic neurons in zebrafish larvae, which project to the hypothalamus, hindbrain, and spinal cord, including regions that express the two zebrafish QRFP receptor paralogs. We find that the overexpression of QRFP inhibits locomotor activity during the day, whereas mutation ofqrfpor its receptors results in increased locomotor activity and decreased sleep during the day. Despite the restriction of these phenotypes to the day, the circadian clock does not regulateqrfpexpression, and entrained circadian rhythms are not required for QRFP-induced rest. Instead, we find that QRFP overexpression decreases locomotor activity largely in a light-specific manner. Our results suggest that QRFP signaling plays an important role in promoting sleep and may underlie some aspects of hypothalamic sleep control.SIGNIFICANCE STATEMENTThe hypothalamus is thought to play a key role in regulating sleep in vertebrate animals, but few sleep-promoting signaling pathways that function in the hypothalamus have been identified. Here we use the zebrafish, a diurnal vertebrate, to functionally and anatomically characterize the neuropeptide QRFP. We show that QRFP is exclusively expressed in a small number of neurons in the larval zebrafish hypothalamus that project widely in the brain. We also show that QRFP overexpression reduces locomotor activity, whereas animals that lack QRFP signaling are more active and sleep less. These results suggest that QRFP signaling participates in the hypothalamic regulation of sleep.
Amiloride-Insensitive Salt Taste Is Mediated by Two Populations of Type III Taste Cells with Distinct Transduction Mechanisms
Authors: Lewandowski Brian C. , Sukumaran Sunil K. , Margolskee Robert F. , Bachmanov Alexander A. 
Published: February 2016

Responses in the amiloride-insensitive (AI) pathway, one of the two pathways mediating salty taste in mammals, are modulated by the size of the anion of a salt. This “anion effect” has been hypothesized to result from inhibitory transepithelial potentials (TPs) generated across the lingual epithelium as cations permeate through tight junctions and leave their larger and less permeable anions behind (Ye et al., 1991). We tested directly the necessity of TPs for the anion effect by measuring responses to NaCl and Na-gluconate (small and large anion sodium salts, respectively) in isolated taste cells from mouse circumvallate papillae. Using calcium imaging, we identified AI salt-responsive type III taste cells and demonstrated that they compose a subpopulation of acid-responsive taste cells. Even in the absence of TPs, many (66%) AI salt-responsive type III taste cells still exhibited the anion effect, demonstrating that some component of the transduction machinery for salty taste in type III cells is sensitive to anion size. We hypothesized that osmotic responses could explain why a minority of type III cells (34%) had AI salt responses but lacked anion sensitivity. All AI type III cells had osmotic responses to cellobiose, which were significantly modulated by extracellular sodium concentration, suggesting the presence of a sodium-conducting osmotically sensitive ion channel. However, these responses were significantly larger in AI type III cells that did not exhibit the anion effect. These findings indicate that multiple mechanisms could underlie AI salt responses in type III taste cells, one of which may contribute to the anion effect.SIGNIFICANCE STATEMENTUnderstanding the mechanisms underlying salty taste will help inform strategies to combat the health problems associated with NaCl overconsumption by humans. Of the two pathways underlying salty taste in mammals, the amiloride-insensitive (AI) pathway is the least understood. Using calcium imaging of isolated mouse taste cells, we identify two separate populations of AI salt-responsive type III taste cells distinguished by their sensitivity to anion size and show that these cells compose subpopulations of acid-responsive taste cells. We also find evidence that a sodium-conducting osmotically sensitive mechanism contributes to salt responses in type III taste cells. Our data not only provide new insights into the transduction mechanisms of AI salt taste but also have important implications for general theories of taste encoding.
Aerobic Glycolysis in the Frontal Cortex Correlates with Memory Performance in Wild-Type Mice But Not the APP/PS1 Mouse Model of Cerebral Amyloidosis
Authors: Harris Richard A. , Tindale Lauren , Lone Asad , Singh Olivia , Macauley Shannon L. , Stanley Molly , Holtzman David M. , Bartha Robert , Cumming Robert C. 
Published: February 2016

Aerobic glycolysis and lactate production in the brain plays a key role in memory, yet the role of this metabolism in the cognitive decline associated with Alzheimer's disease (AD) remains poorly understood. Here we examined the relationship between cerebral lactate levels and memory performance in an APP/PS1 mouse model of AD, which progressively accumulates amyloid-β.In vivo1H-magnetic resonance spectroscopy revealed an age-dependent decline in lactate levels within the frontal cortex of control mice, whereas lactate levels remained unaltered in APP/PS1 mice from 3 to 12 months of age. Analysis of hippocampal interstitial fluid byin vivomicrodialysis revealed a significant elevation in lactate levels in APP/PS1 mice relative to control mice at 12 months of age. An age-dependent decline in the levels of key aerobic glycolysis enzymes and a concomitant increase in lactate transporter expression was detected in control mice. Increased expression of lactate-producing enzymes correlated with improved memory in control mice. Interestingly, in APP/PS1 mice the opposite effect was detected. In these mice, increased expression of lactate producing enzymes correlated with poorer memory performance. Immunofluorescent staining revealed localization of the aerobic glycolysis enzymes pyruvate dehydrogenase kinase and lactate dehydrogenase A within cortical and hippocampal neurons in control mice, as well as within astrocytes surrounding amyloid plaques in APP/PS1 mice. These observations collectively indicate that production of lactate, via aerobic glycolysis, is beneficial for memory function during normal aging. However, elevated lactate levels in APP/PS1 mice indicate perturbed lactate processing, a factor that may contribute to cognitive decline in AD.SIGNIFICANCE STATEMENTLactate has recently emerged as a key metabolite necessary for memory consolidation. Lactate is the end product of aerobic glycolysis, a unique form of metabolism that occurs within certain regions of the brain. Here we detected an age-dependent decline in the expression of aerobic glycolysis enzymes and a concomitant decrease in lactate levels within the frontal cortex of wild-type mice. Improved memory performance in wild-type mice correlated with elevated expression of aerobic glycolysis enzymes. Surprisingly, lactate levels remained elevated with age and increased aerobic glycolysis enzyme expression correlated with poorer memory performance in APP/PS1 mice. These findings suggest that while lactate production is beneficial for memory in the healthy aging brain, it might be detrimental in an Alzheimer's disease context.
Age-Related Changes in Frontal Network Structural and Functional Connectivity in Relation to Bimanual Movement Control
Authors: Fujiyama Hakuei , Van Soom Jago , Rens Guy , Gooijers Jolien , Leunissen Inge , Levin Oron , Swinnen Stephan P. 
Published: February 2016

Changes in both brain structure and neurophysiological function regulating homotopic as well as heterotopic interhemispheric interactions (IHIs) are assumed to be responsible for the bimanual performance deficits in older adults. However, how the structural and functional networks regulating bimanual performance decline in older adults, as well as the interplay between brain structure and function remain largely unclear. Using a dual-site transcranial magnetic stimulation paradigm, we examined the age-related changes in the interhemispheric effects from the dorsolateral prefrontal cortex and dorsal premotor cortex onto the contralateral primary motor cortex (M1) during the preparation of a complex bimanual coordination task in human. Structural properties of these interactions were assessed with diffusion-based fiber tractography. Compared with young adults, older adults showed performance declines in the more difficult bimanual conditions, less optimal brain white matter (WM) microstructure, and a decreased ability to regulate the interaction between dorsolateral prefrontal cortex and M1. Importantly, we found that WM microstructure, neurophysiological function, and bimanual performance were interrelated in older adults, whereas only the task-related changes in IHI predicted bimanual performance in young adults. These results reflect unique interactions between structure and function in the aging brain, such that declines in WM microstructural organization likely lead to dysfunctional regulation of IHI, ultimately accounting for bimanual performance deficits.SIGNIFICANCE STATEMENTThe structural and functional changes in the aging brain are associated with a decline in movement control, compromising functional independence. We used MRI and noninvasive brain stimulation techniques to investigate white matter microstructural organization and neurophysiological function in the aging brain, in relation to bimanual movement control. We found that less optimal brain microstructural organization and task-related modulations in neurophysiological function resulted in poor bimanual performance in older adults. By interrelating brain structure, neurophysiological function, and behavior, the current study provides a comprehensive picture of biological alterations in the aging brain that underlie declines in bimanual performance.
Astrocytic GAP43 Induced by the TLR4/NF-κB/STAT3 Axis Attenuates Astrogliosis-Mediated Microglial Activation and Neurotoxicity
Authors: Hung Chia-Chi , Lin Chun-Hua , Chang Hsuan , Wang Chen-Yu , Lin Shang-Hsuan , Hsu Pei-Chien , Sun Yu-Yo , Lin Teng-Nan , Shie Feng-Shiun , Kao Lung-Sen , Chou Chih-Ming , Lee Yi-Hsuan 
Published: February 2016

Growth-associated protein 43 (GAP43), a protein kinase C (PKC)-activated phosphoprotein, is often implicated in axonal plasticity and regeneration. In this study, we found that GAP43 can be induced by the endotoxin lipopolysaccharide (LPS) in rat brain astrocytes bothin vivoandin vitro. The LPS-induced astrocytic GAP43 expression was mediated by Toll-like receptor 4 and nuclear factor-κB (NF-κB)- and interleukin-6/signal transducer and activator of transcription 3 (STAT3)-dependent transcriptional activation. The overexpression of the PKC phosphorylation-mimicking GAP43S41D(constitutive active GAP43) in astrocytes mimicked LPS-induced process arborization and elongation, while application of a NF-κB inhibitory peptide TAT-NBD or GAP43S41A(dominant-negative GAP43) or knockdown of GAP43 all inhibited astrogliosis responses. Moreover, GAP43 knockdown aggravated astrogliosis-induced microglial activation and expression of proinflammatory cytokines. We also show that astrogliosis-conditioned medium from GAP43 knock-down astrocytes inhibited GAP43 phosphorylation and axonal growth, and increased neuronal damage in cultured rat cortical neurons. These proneurotoxic effects of astrocytic GAP43 knockdown were accompanied by attenuated glutamate uptake and expression of the glutamate transporter excitatory amino acid transporter 2 (EAAT2) in LPS-treated astrocytes. The regulation of EAAT2 expression involves actin polymerization-dependent activation of the transcriptional coactivator megakaryoblastic leukemia 1 (MKL1), which targets the serum response elements in the promoter of ratSlc1a2gene encoding EAAT2. In sum, the present study suggests that astrocytic GAP43 mediates glial plasticity during astrogliosis, and provides beneficial effects for neuronal plasticity and survival and attenuation of microglial activation.SIGNIFICANCE STATEMENTAstrogliosis is a complex state in which injury-stimulated astrocytes exert both protective and harmful effects on neuronal survival and plasticity. In this study, we demonstrated for the first time that growth-associated protein 43 (GAP43), a well known growth cone protein that promotes axonal regeneration, can be induced in rat brain astrocytes by the proinflammatory endotoxin lipopolysaccharide via both nuclear factor-κB and signal transducer and activator of transcription 3-mediated transcriptional activation. Importantly, LPS-induced GAP43 mediates plastic changes of astrocytes while attenuating astrogliosis-induced microglial activation and neurotoxicity. Hence, astrocytic GAP43 upregulation may serve to indicate beneficial astrogliosis after CNS injury.
Evidence That the Laminar Fate of LGE/CGE-Derived Neocortical Interneurons Is Dependent on Their Progenitor Domains
Authors: Torigoe Makio , Yamauchi Kenta , Kimura Toshiya , Uemura Yo , Murakami Fujio 
Published: February 2016

Neocortical interneurons show tremendous diversity in terms of their neurochemical marker expressions, morphology, electrophysiological properties, and laminar fate. Allocation of interneurons to their appropriate regions and layers in the neocortex is thought to play important roles for the emergence of higher functions of the neocortex. Neocortical interneurons mainly originate from the medial ganglionic eminence (MGE) and the caudal ganglionic eminence (CGE). The diversity and the laminar fate of MGE-derived interneurons depend on the location of their birth and birthdate, respectively. However, this relationship does not hold for CGE-derived interneurons. Here, using the method ofin uteroelectroporation, which causes arbitrary occurrence of labeled progenitor domains, we tracked all descendants of the lateral ganglionic eminence (LGE)/CGE progenitors in mice. We provide evidence that neocortical interneurons with distinct laminar fate originate from distinct progenitor domains within the LGE/CGE. We find layer I interneurons are predominantly labeled in a set of animals, whereas other upper layer neurons are predominantly labeled in another set. We also find distinct subcortical structures labeled between the two sets. Further, interneurons labeled in layer I show distinct neurochemical properties from those in other layers. Together, these results suggest that the laminar fate of LGE/CGE-derived interneurons depends on their spatial origin.SIGNIFICANCE STATEMENTDiverse types of neocortical interneurons have distinct laminar fate, neurochemical marker expression, morphology, and electrophysiological properties. Although the specifications and laminar fate of medial ganglionic eminence-derived neocortical interneurons depend on their location of embryonic origin and birthdate, no similar causality of lateral/caudal ganglionic eminence (LGE/CGE)-derived neocortical interneurons is known. Here, we performedin uteroelectroporation on mouse LGE/CGE and found two groups of animals, one with preferential labeling of layer I and the other with preferential labeling of other layers. Interneurons labeled in these two groups show distinct neurochemical properties and morphologies and are associated with labeling of distinct subcortical structures. These findings suggest that the laminar fate of LGE/CGE-derived neocortical interneurons depends on their spatial origin.
Un modelo integrado para el fortalecimiento de la gestión pública (Sistema de Gestión de Calidad - Balance Scorecard)
Authors: Riaño Vargas Jairo Arturo , Avendaño Sánchez Camilo Eduardo 
Published: February 2016

<p>La articulación del Sistema de Gestión de Calidad con el Cuadro de Mando Integral (Balance Scorecard) en organizaciones del sector público en Colombia, busca la consolidación y estandarización de un sistema integrado que permita medir y evaluar el desarrollo de la estrategia institucional con relación a su visión y planeación, em términos de eficiencia, eficacia y efectividad, para garantizar el cumplimientodel objetivo social de las organizaciones, lo que finalmente redundará en el desarrollo economico y social del país. </p>
Reflexiones sobre las características constitutivas de la gestión integral
Authors: Tejada Losada Fabio , Peña Guarin Guillermo 
Published: February 2016

<p>En este artículo se presenta la forma como se interpreta el concepto de "gestión integral" en el contexto de la Maestría en Calidad y Gestión Integral. Para ello se analiza en primer lugar el concepto de "la calidad", planteándose una visión ampliada del mismo que excede la relación tradicional entre un cliente y su proveedor. Posteriormente se analiza la configuración interna de una organización a partir de cuatro elementos diferenciados pero articulados entre sí: la estructura del negocio, el direccionamiento estratégico, la cultura de la organización y los sistemas de gestión; estos últimos deberían estar integrados con base en la compartibilidad de sus elementos.</p><p>Pero la gestión integral incluye también elementos externos a la organización relacionados, en el enfoque de está Maestría, con los tres componentes del desarrollo sostenible: el crecimiento económico, la protección del medio ambiente y la cohesión social; de modo que la gestión integral debe abarcar la compleja integración de los elementos internos y externos que permiten la sostenibilidad organizacional.</p><p> </p>
Efectos de los sistemas de gestión de la calidad normalizados en las PYMES: implicaciones en la responsabilidad social empresarial
Authors: Barrera Tolosa Luis Humberto , Vásquez Alejo Yenny Zulima 
Published: February 2016

<p>El documento muestra los resultados de la aplicación de dos instrumentos (encuesta y entrevista) a la posible relación de causalidad entre el sistema de gestión de calidad y la responsabilidad social. Se busca establecer qué instrumento es más eficiente y realizar una corroboración de campo del marco teórico a manera de prueba piloto, por medio de la aplicación de la encuesta a expertos y la entrevista en profundidad en empresas. Los resultados muestran que los sistemas normalizados de gestión de la calidad y la responsabilidad en las Pymes están mediados por los valores, los principios, las políticas, la cultura organizacional, las partes interesadas, las estrategias y las acciones, elementos que se convierten en base común, tanto para los sistemas normalizados de gestión de la calidad, como para la responsabilidad social en las empresas. Se concluye que la gestión de la calidad y la responsabilidad son el producto de esta mediación por parte de los directivos organizacionales.</p><p> </p><p> </p><p> </p>
La gestión del conocimiento y su relación con la gestión de la calidad, en instituciones del sector agropecuario dedicadas a la ciencia y la tecnología
Authors: Ramírez González Margarita 
Published: February 2016

<p>El momento actual se señala como un cambio de época , denominado la era del conocimiento y la información. Los recursos tradicionales generadores de valor como la tierra o el capital financiero, dejan de ser los motores de la economía para dar paso a un nuevo recurso de generación de valor: la información y el conocimiento. Las nuevas fuentes de competitividad y creación de riqueza en las organizaciones, basadas en el conocimiento, se pueden gestionar según el ciclo PHVA (Planear, Hacer, Verificar y Actuar).</p><p>En Colombia las entidades de ciencia y tecnología en el sector agropecuario comienzan a implementar sistemas de gestión de la calidad y excelencia, pero pocos avances se conocen en la gestión del conocimiento. La presente investigación estudió dos instituciones del sector agropecuario dedicadas a la ciencia y tecnologia: el Instituto Colombiano Agropecuario - ICA y la Corporación Colombiana de Investigación Agropecuaria - CORPOICA -, las cuales cuentan con sistemas de gestión de la calidad implementados. El estudio abordó las congruencias, afinidades o inconsistencias que se encuentran entre sus sistemas de gestión de la calidad y los elementos de la gestión del conocimiento, identificados en las categorias de: capital intelectual, flujo de conocimiento, cultura del aprendizaje, cultura de la innovación y mejora continua.</p><p>A partir del análisis crítico del marco teórico, se elabora una matriz categorial como resultado de la identificación de conceptos clave llevados a categorias, hallados en los distintos enfoques y modelos de la gestión del conocimiento y la gestión de la calidad. Los instrumentos diseñados a partir de la matriz categorial para la recolección de información y para su análisis permiten contar con una información pertinente y apropiada para elaborar una propuesta final para implementar la gestión del conocimiento desde el enfoque de calidad y excelencia. </p><p> </p>