Brain Pathol
July 2024
Alzheimer's disease (AD), the most prevalent neurodegenerative disorder worldwide, is clinically characterized by cognitive deficits. Neuropathologically, AD brains accumulate deposits of amyloid-β (Aβ) and tau proteins. Furthermore, these misfolded proteins can propagate from cell to cell in a prion-like manner and induce native proteins to become pathological.
View Article and Find Full Text PDFα-Synuclein, a protein mostly present in presynaptic terminals, accumulates neuropathologically in Parkinson's disease in a 6-stage sequence and propagates in the nervous system in a prion-like manner through neurons and glia. In stage 3, the substantia nigra are affected, provoking motor symptoms and the amygdaloid complex, leading to different nonmotor symptoms; from here, synucleinopathy spreads to the temporal cortex and beyond. The expected increase in Parkinson's disease incidence accelerates the need for detection biomarkers; however, the heterogeneity of this disease, including pathological aggregates and pathophysiological pathways, poses a challenge in the search for new therapeutic targets and biomarkers.
View Article and Find Full Text PDFAlzheimer's disease (AD) is characterized by the accumulation of pathological amyloid-β (Aβ) and Tau proteins. According to the prion-like hypothesis, both proteins can seed and disseminate through brain regions through neural connections and glial cells. The amygdaloid complex (AC) is involved early in the disease, and its widespread connections with other brain regions indicate that it is a hub for propagating pathology.
View Article and Find Full Text PDFHyposmia is one of the prodromal symptoms of Parkinson's disease (PD) and a red flag in clinical diagnosis. Neuropathologically, this sign correlates with α-synuclein involvement in the anterior olfactory nucleus (AON). Neurodegeneration, microgliosis, and astrogliosis in AON are poorly studied, and bulbar AON is the focus of these studies with contradictory results.
View Article and Find Full Text PDFIntroduction: The entorhinal cortex is among the earliest areas involved in Alzheimer's disease. Volume reduction and neural loss in this area have been widely reported. Human entorhinal cortex atrophy is, in part, due to neural loss, but microglial and/or astroglial involvement in the different layers remains unclear.
View Article and Find Full Text PDFAlzheimer's disease (AD), the most prevalent neurodegenerative disorder, is characterized by executive dysfunction and memory impairment mediated by the accumulation of extracellular amyloid-β peptide (Aβ) and intracellular hyperphosphorylated tau protein. The hippocampus (HIPP) is essential for memory formation and is involved in early stages of disease. In fact, hippocampal atrophy is used as an early biomarker of neuronal injury and to evaluate disease progression.
View Article and Find Full Text PDFAlzheimer's disease (AD) is the most prevalent neurodegenerative disease in the elderly. Progressive accumulation of insoluble isoforms of amyloid-β peptide (Aβ) and tau protein are the major neuropathologic hallmarks, and the loss of cholinergic pathways underlies cognitive deficits in patients. Recently, glial involvement has gained interest regarding its effect on preservation and impairment of brain integrity.
View Article and Find Full Text PDFBackground: Parkinson's disease (PD) is a prevalent neurodegenerative disease that is pathologically described as a six-stage α-synucleinopathy. In stage 4, α-synuclein reaches the hippocampus, inducing cognitive deficits, from which it progresses to the isocortex, leading to dementia. Among hippocampal fields, cornu ammonis 2 is particularly affected by this α-synucleinopathy and critical for cognitive decline.
View Article and Find Full Text PDFDissections are a fundamental practical methodology for teaching human anatomy. However, this experience can be stressful, generating anxiety situations among students. This study tries to understand the attitudes, reactions, fears and anxiety state among students earning a physiotherapy degree when facing their first prosection.
View Article and Find Full Text PDFHyposmia is prodromal, and male sex is a risk marker for an enhanced likelihood ratio of Parkinson's disease. The literature regarding olfactory bulb volume reduction is controversial, although the olfactory bulb has been largely reported as an early and preferential site for α-synucleinopathy. These pathological deposits have been correlated with neural loss in Nissl-stained material.
View Article and Find Full Text PDFAlzheimer's and Parkinson's diseases are the most prevalent neurodegenerative disorders. Their etiologies are idiopathic, and treatments are symptomatic and orientated towards cognitive or motor deficits. Neuropathologically, both are proteinopathies with pathological aggregates (plaques of amyloid-β peptide and neurofibrillary tangles of tau protein in Alzheimer's disease, and Lewy bodies mostly composed of α-synuclein in Parkinson's disease).
View Article and Find Full Text PDFBackground: The teaching of human anatomy is often based on practices of cadaver dissection and prosected specimens. However, exposure to human cadavers might be stressful and anxiety-inducing for students. The aim of this study is to explore the degree of satisfaction and anxiety among first-year students in the Medicine, Occupational Therapy, Speech Therapy and Nursing programmes at the Universidad de Castilla-La Mancha (Spain) who are experiencing their first dissection/prosection practice to develop stress coping strategies.
View Article and Find Full Text PDFAlzheimer's and Parkinson's diseases are the most prevalent neurodegenerative disorders in aging. Hyposmia has been described as an early symptom that can precede cognitive and motor deficits by decades. Certain regions within the olfactory system, such as the anterior olfactory nucleus, display the neuropathological markers tau and amyloid-β or α-synuclein from the earliest stages of disease progression in a preferential manner.
View Article and Find Full Text PDFDissection and prosection practices using human cadavers are a key component of macroscopic anatomy education in different Health Sciences university degrees. However, first-hand interaction with cadavers can be distressing for students, generating anxiety on a number of levels. This study aims to shed light on the reactions, fears and different states of anxiety experienced by nursing students in to a single anatomy room experience over a five-hour period, and examined reactions pre and post same.
View Article and Find Full Text PDFBackground: Intracerebral inoculation of extracts from post-mortem human Alzheimer's disease brains into mice produces a prion-like spreading effect of amyloid-β. The differences observed between these extracts and the synthetic peptide, in terms of amyloid-β internalization and seed and cell-to-cell transmission of cytosolic protein aggregates, suggest that brain extracts contain key contributors that enhance the prion-like effect of amyloid-β. Nevertheless, these potential partners are still unknown due to the complexity of whole brain extracts.
View Article and Find Full Text PDFActa Neuropathol Commun
April 2019
Parkinson's disease is characterized by a proteinopathy that includes aggregates of α-synuclein. A recent hypothesis proposes a prion-like spreading mechanism for this α-synucleinopathy. Early neuropathological deposits occur, among others, in the anterior olfactory nucleus (AON).
View Article and Find Full Text PDFThis Special Issue entitled "Cranial Nerves: phylogeny, ontogeny, morphology and clinical significance" has been divided into two consecutive volumes. This second volume is devoted to morphology and clinical relevance. Articles in this volume examine these topics from a macroscopic point of view and with a surgical interest.
View Article and Find Full Text PDFThis Special Issue, entitled "Cranial Nerves: phylogeny, ontogeny, morphology and clinical significance," has been divided into two consecutive volumes. We present here the first volume, devoted to phylogeny and ontogeny. Articles in this volume examine these two topics from a microscopic point of view.
View Article and Find Full Text PDFPractical training in the dissection of human cadavers is a fundamental and traditional component of human anatomy education in medical schools. This practice, however, can be stressful for students and can generate a certain amount of anxiety. The aim of this study is to explore the attitudes, reactions, and anxiety levels of first-year medical students when working in the dissecting room, over a period of one year, and to relate these anxiety levels to the results of our educational program.
View Article and Find Full Text PDFOriginally discovered in elasmobranchs by Fritsh in 1878, the nervus terminalis has been found in virtually all species, including humans. After more than one-century debate on its nomenclature, it is nowadays recognized as cranial pair zero. The nerve mostly originates in the olfactory placode, although neural crest contribution has been also proposed.
View Article and Find Full Text PDFSynucleinopathies (including α-synucleinopathies), which include Parkinson's disease (PD), manifest themsevles early on (stage 1) in the olfactory system; preferentially in the anterior olfactory nucleus (AON). In particular, the non-motor, early manifestations of PD include hyposmia, which is the partial loss of the sense of smell. The neural basis of hyposmia in PD, however, is poorly understood; but the AON appears to be a key structure in the disease's progression.
View Article and Find Full Text PDFOlfactory dysfunction and emotional impairment are nonmotor symptoms in Parkinson disease (PD). These symptoms might be correlated with the appearance of Lewy bodies and neurites (ubiquitin and α-synuclein aggregates) in the amygdala (Braak stage 3). α-Synucleinopathy in the amygdala has been studied only occasionally, and no data on cell types involved are available.
View Article and Find Full Text PDFHuman anatomy education often utilizes the essential practices of cadaver dissection and examination of prosected specimens. However, these exposures to human cadavers and confronting death can be stressful and anxiety-inducing for students. This study aims to understand the attitudes, reactions, fears, and states of anxiety that speech therapy students experience in the dissection room.
View Article and Find Full Text PDFAlzheimer's disease (AD) is the most prevalent neurodegenerative disease, mostly idiopathic and with palliative treatment. Neuropathologically, it is characterized by intracellular neurofibrillary tangles of tau protein and extracellular plaques of amyloid β peptides. The relationship between AD and neurogenesis is unknown, but two facts are particularly relevant.
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