Search results for "Degeneration"
showing 10 items of 601 documents
Lesions of the dopaminergic innervation of the nucleus accumbens medial shell delay the generation of preference for sucrose, but not of sexual phero…
2011
Male sexual pheromones are rewarding stimuli for female mice, able to induce conditioned place preference. To test whether processing these natural reinforcing stimuli depends on the dopaminergic innervation of the nucleus accumbens, as for other natural rewards, we compare the effects of specific lesions of the dopaminergic innervation of the medial shell of the nucleus accumbens on two different appetitive behaviours, ‘pheromone seeking’ and sucrose preferential intake. Female mice, with no previous experience with either adult male chemical stimuli or with sucrose, received injections of 6-hydroxydopamine (or vehicle) in the medial shell of the accumbens. Then, we analyzed their preferen…
Cerebral expression of neuroglobin and cytoglobin after deep hypothermic circulatory arrest in neonatal piglets
2010
Deep hypothermic circulatory arrest (DHCA) is used in corrective cardiac surgery for complex congenital heart disease. Endogenous protective mechanisms may be responsible for the prevention of brain damage after hypothermic ischemia. Neuroglobin and cytoglobin are expressed in brain cells and appear to modulate hypoxic-ischemic brain injury. However, their neuroprotective potency is still not understood. Thus the aim of this study was to detect the influence exerted by DHCA on their expression.The effects of DHCA were analyzed in a neonatal piglet model with cardiopulmonary bypass, DHCA of 60 and 120 min and subsequent reperfusion of 6h. Complete histological analysis and changes in the mRN…
Vulnerability of peripheral catecholaminergic neurons to MPTP is not regulated by alpha-synuclein.
2010
Although generally considered a prototypical movement disorder, Parkinson's disease is commonly associated with a broad-spectrum of non-motor symptoms, including autonomic dysfunctions caused by significant alterations in catecholaminergic neurons of the peripheral sympathetic nervous system. Here we present evidence that alpha-synuclein is highly expressed by sympathetic ganglion neurons throughout embryonic and postnatal life and that it is found in tyrosine hydroxylase-positive sympathetic fibers innervating the heart of adult mice. However, mice deficient in alpha-synuclein do not exhibit any apparent alterations in sympathetic development. Sympathetic neurons isolated from mouse embryo…
The Erythrocytic Hypothesis of Brain Energy Crisis in Sporadic Alzheimer Disease: Possible Consequences and Supporting Evidence
2020
Alzheimer’s disease (AD) is a fatal form of dementia of unknown etiology. Although amyloid plaque accumulation in the brain has been the subject of intensive research in disease pathogenesis and anti-amyloid drug development; the continued failures of the clinical trials suggest that amyloids are not a key cause of AD and new approaches to AD investigation and treatment are needed. We propose a new hypothesis of AD development based on metabolic abnormalities in circulating red blood cells (RBCs) that slow down oxygen release from RBCs into brain tissue which in turn leads to hypoxia-induced brain energy crisis; loss of neurons; and progressive atrophy preceding cognitive dysfunction. This …
Subventricular zone in motor neuron disease with frontotemporal dementia.
2011
Investigate how the subventricular proliferation and organisation is modified in a patient with FTLD-ALS. We studied the subventricular zone (SVZ) of a patient with FTLD-ALS immunohistochemical and histologically. We found an increase of Ki-67 positive cells and neuroblast in the subventricular zone, suggesting an activation of proliferating activity in response to FTD-ALS. This proliferation can act as a compensatory mechanism for rapid neuronal death and its modulation could provide a new therapeutic pathway in ALS. These results suggest a modification of neurogenesis in FTD-ALS. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
Aβ Oligomers and Fibrillar Aggregates Induce Different Apoptotic Pathways in LAN5 Neuroblastoma Cell Cultures
2009
Fibril deposit formation of amyloid beta-protein (Abeta) in the brain is a hallmark of Alzheimer's disease (AD). Increasing evidence suggests that toxicity is linked to diffusible Abeta oligomers, which have been found in soluble brain extracts of AD patients, rather than to insoluble fibers. Here we report a study of the toxicity of two distinct forms of recombinant Abeta small oligomers and fibrillar aggregates to simulate the action of diffusible Abeta oligomers and amyloid plaques on neuronal cells. Different techniques, including dynamic light scattering, fluorescence, and scanning electron microscopy, have been used to characterize the two forms of Abeta. Under similar conditions and …
The role of mitochondrial transition pore, and its modulation, in traumatic brain injury and delayed neurodegeneration after TBI
2009
Following severe traumatic brain injury (TBI), a complex interplay of pathomechanism, such as exitotoxicity, oxidative stress, inflammatory events, and mitochondrial dysfunction occurs. This leads to a cascade of neuronal and axonal pathologies, which ultimately lead to axonal failure, neuronal energy metabolic failure, and neuronal death, which in turn determine patient outcome. For mild and moderate TBI, the pathomechanism is similar but much less frequent and ischemic cell death is unusual, except with mass lesions. Involvement of mitochondria in acute post-traumatic neurodegeneration has been extensively studied during the last decade, and there are a number of investigations implicatin…
D2R striatopallidal neurons inhibit both locomotor and drug reward processes.
2009
The specific functions of dopamine D(2) receptor-positive (D(2)R) striatopallidal neurons remain poorly understood. Using a genetic mouse model, we found that ablation of D(2)R neurons in the entire striatum induced hyperlocomotion, whereas ablation in the ventral striatum increased amphetamine conditioned place preference. Thus D(2)R striatopallidal neurons limit both locomotion and, unexpectedly, drug reinforcement.
Impact of Chaperonopathies in Protein Homeostasis and Beyond
2013
Chaperones have functions other than those classically attributed to them pertaining to protein homeostasis. These “other” non-canonical functions are the focus of chapter 8. The close interaction of the chaperoning and the immune systems and the impact of their malfunctioning on aging and cancer are highlighted. Conversely, the impact of ageing and cancer on the two systems is also underscored. The connections between stress, protein damage (including chaperones), protein misfolding, protein aggregation and precipitation, and tissue degeneration, are analyzed, indicating that all these processes are aggravated by a decline in chaperoning potential with aging (chaperonopathies of the aged) …
Towards the new spectral-domain optical coherence tomography based classification of age-related macular degeneration
2012
Introducción: La degeneración macular asociada a la edad (DMAE) es un problema sociosanitario de primer orden en las sociedades industrializadas. La aportación de las nuevas técnicas diagnósticas, fundamentalmente la tomografía de coherencia óptica de dominio espectral (SD-OCT), ha ayudado a comprender mejor esta enfermedad. Objetivo: Recordar la clasificación clínica vigente de la DMAE, exponer la nueva clasificación tomográfica de la DMAE exudativa, y revisar los nuevos nuevos hallazgos tomográficos de la degeneración macular seca. Desarrollo: Clásicamente se distinguen dos formas de DMAE: seca y exudativa; asimismo existen tres estadios progresivos de severidad: precoz, intermedio y tard…