Helmut Heinsen
Universidade de São Paulo, Patologia, Department Member
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The farnesyltransferase inhibitor lonafarnib reduces tau inclusion burden and atrophy in familial tauopathy models by inhibiting farnesylation on the Ras GTPase, Rhes, and activating autophagy. While hinting at a role of Rhes in tau... more
The farnesyltransferase inhibitor lonafarnib reduces tau inclusion burden and atrophy in familial tauopathy models by inhibiting farnesylation on the Ras GTPase, Rhes, and activating autophagy. While hinting at a role of Rhes in tau aggregation, it is unclear how translatable these results are for sporadic forms of tauopathy. We used a combination of quantitative pathology using multiplex immunofluorescence for Rhes, several tau post-translational modifications, and single nucleus RNA sequence analysis to interrogate Rhes presence and distribution in human cortical neurons and Rhes relation to tau and TDP-43 changes. snRNA data suggest that Rhes is found in all cortical neuron subpopulations, not only in striatum cells. Histologic investigation in hippocampal formation from multiple postmortem cases in five different tauopathies and healthy controls and TDP-43 proteinopathy showed that nearly all neurons in control brains display a pattern of diffuse cytoplasmic Rhes positivity. How...
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Immunofluorescence (IF) plays a major role in quantifying protein expression in situ and understanding cell function. It is widely applied in assessing disease mechanisms and in drug discovery research. Automation of IF analysis can... more
Immunofluorescence (IF) plays a major role in quantifying protein expression in situ and understanding cell function. It is widely applied in assessing disease mechanisms and in drug discovery research. Automation of IF analysis can transform studies using experimental cell models. However, IF analysis of postmortem human tissue relies mostly on manual interaction, often subjected to low-throughput and prone to error, leading to low inter and intra-observer reproducibility. Human postmortem brain samples challenges neuroscientists because of the high level of autofluorescence caused by accumulation of lipofuscin pigment during aging, hindering systematic analyses. We propose a method for automating cell counting and classification in IF microscopy of human postmortem brains. Our algorithm speeds up the quantification task while improving reproducibility. Dictionary learning and sparse coding allow for constructing improved cell representations using IF images. These models are input...
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Hyperphosphorylated tau-neuronal cytoplasmic inclusions (ht-NCI) are the best protein correlate of clinical decline in Alzheimer's disease (AD). Qualitative evidence identifies ht-NCI accumulating in the isodendritic core before the... more
Hyperphosphorylated tau-neuronal cytoplasmic inclusions (ht-NCI) are the best protein correlate of clinical decline in Alzheimer's disease (AD). Qualitative evidence identifies ht-NCI accumulating in the isodendritic core before the entorhinal cortex. Here, we used unbiased stereology to quantify ht-NCI burden in the locus coeruleus and dorsal raphe nucleus, aiming to characterize the impact of AD pathology in these nuclei with a focus on early stages. We utilized unbiased stereology in a sample of 48 well-characterized subjects enriched for controls and early AD stages. ht-NCI counts were estimated in 60 μm-thick sections immunostained for p-tau throughout LC and DRN. Data were integrated with unbiased estimates of LC and DRN neuronal population for a subset of cases. In Braak stage 0, 7.9% and 2.6% of neurons in LC and DRN, respectively, harbor ht-NCIs. Although the number of ht-NCI+ neurons significantly increased by about 1.9x between Braak stages 0-I in LC (p = 0.02), we fa...
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Glutamat ist der wichtigste exzitatorische Neurotransmitter in der hippocampalen Formation des Saugergehirnes. Der N-Methyl-D-Aspartat-Rezeptor (NMDA), einer von mehreren Glutamatrezeptoren [3], durfte eine entscheidende Rolle bei der... more
Glutamat ist der wichtigste exzitatorische Neurotransmitter in der hippocampalen Formation des Saugergehirnes. Der N-Methyl-D-Aspartat-Rezeptor (NMDA), einer von mehreren Glutamatrezeptoren [3], durfte eine entscheidende Rolle bei der Speicherung von Gedachtnisinhalten spielen [2]. Entsprechend der pathologischen Zellmorphologie bei neurodegenerativen Erkrankungen mit Merkfahigkeitsstorungen wurden veranderte Dichten von NMDA-Rezeptoren gemessen [4, 1].
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Colon cancer is one of the most common tumors in the human population. Recent studies have shown a reduced risk for colon cancer in patients given the antidepressant fluoxetine (FLX). The exact mechanism by which FLX might protect from... more
Colon cancer is one of the most common tumors in the human population. Recent studies have shown a reduced risk for colon cancer in patients given the antidepressant fluoxetine (FLX). The exact mechanism by which FLX might protect from colon cancer remains however controversial. Here, FLX reduced the development of different colon tumor xenografts, as well as proliferation in hypoxic tumor areas within them. FLX treatment also decreased microvessel numbers in tumors. Although FLX did not increase serum and tumor glucose levels as much as the colon chemotherapy goldstandard Fluorouracil did, lactate levels were significantly augmented within tumors by FLX treatment. The gene expression of the MCT4 lactate transporter was significantly downregulated. Total protein amounts from the third and fifth mitochondrial complexes were significantly decreased by FLX in tumors. Cell culture experiments revealed that FLX reduced the mitochondrial membrane potential significantly and disabled the r...
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In a quantitative study on thick frozen sections stained by the Gallyas’ silver impregnation method neurofibrillary tangles (NFT), neuritic plaques (NP) and neuropil threads (NT) in the entorhinal as well as transentorhinal area (Braak... more
In a quantitative study on thick frozen sections stained by the Gallyas’ silver impregnation method neurofibrillary tangles (NFT), neuritic plaques (NP) and neuropil threads (NT) in the entorhinal as well as transentorhinal area (Braak and Braak, 1985) have been evaluated. The amount of NT exceeded by far that of NFT and NP.
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Research Interests: Pathology, Psychology, Cognitive Science, Magnetic Resonance Imaging, Mild Cognitive Impairment, and 15 moreMedicine, Stereology, Humans, Female, Male, Basal forebrain, Clinical Sciences, Aged, Middle Aged, Atrophy, Analysis of Variance, Nucleus Basalis, Alzheimers Disease, Alzheimer Disease, and Neurosciences
Research Interests: Neuroscience, Cognitive Science, Magnetic Resonance Imaging, Medicine, Prefrontal Cortex, and 15 moreExecutive Function, Brain, Humans, Cerebral Cortex, Female, Male, Basal forebrain, Clinical Sciences, Aged, Middle Aged, Atrophy, Neurosciences, Neuropsychological Tests, Forebrain, and Medical and Health Sciences
Significant differences in the content of iron (III) and total iron were found in post mortem substantia nigra of Parkinson's disease. There was an increase of 176% in the levels of total iron and 225% of iron... more
Significant differences in the content of iron (III) and total iron were found in post mortem substantia nigra of Parkinson's disease. There was an increase of 176% in the levels of total iron and 225% of iron (III) in the substantia nigra of the parkinsonian patients compared to age matched controls. In the cortex (Brodmann area 21), hippocampus, putamen, and globus pallidus there was no significant difference in the levels of iron (III) and total iron. Thus the changes in total iron, iron (III) and the iron (II)/iron (III) ratio in the parkinsonian substantia nigra are likely to be involved in the pathophysiology and treatment of this disorder.
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No abstract is available. To read the body of this article, please view the Full Text online. ... © 2008 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved. ... Visit SciVerse ScienceDirect to see if you have... more
No abstract is available. To read the body of this article, please view the Full Text online. ... © 2008 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved. ... Visit SciVerse ScienceDirect to see if you have access via your institution. ... Advertisements on this site ...
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Structural and functional abnormalities of the anterior cingulate cortex (ACC) have frequently been identified in schizophrenia. Alterations of von Economo neurons (VENs), a class of specialized projection neurons, have been found in... more
Structural and functional abnormalities of the anterior cingulate cortex (ACC) have frequently been identified in schizophrenia. Alterations of von Economo neurons (VENs), a class of specialized projection neurons, have been found in different neuropsychiatric disorders and are also suspected in schizophrenia. To date, however, no definitive conclusions can be drawn about quantitative histologic changes in the ACC in schizophrenia because of a lack of rigorous, design-based stereologic studies. In the present study, the volume, total neuron number and total number of VENs in layer V of area 24 were determined in both hemispheres of postmortem brains from 12 male patients with schizophrenia and 11 age-matched male controls. To distinguish global from local effects, volume and total neuron number were also determined in the whole area 24 and whole cortical gray matter (CGM). Measurements were adjusted for hemisphere, age, postmortem interval and fixation time using an ANCOVA model. Co...
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Alzheimer’s disease (AD) is characterized by the selective vulnerability of specific neuronal populations, the molecular signatures of which are largely unknown. To identify and characterize selectively vulnerable neuronal populations, we... more
Alzheimer’s disease (AD) is characterized by the selective vulnerability of specific neuronal populations, the molecular signatures of which are largely unknown. To identify and characterize selectively vulnerable neuronal populations, we used single-nucleus RNA sequencing to profile the caudal entorhinal cortex and the superior frontal gyrus – brain regions where neurofibrillary inclusions and neuronal loss occur early and late in AD, respectively – from postmortem brains spanning the progression of AD-type tau neurofibrillary pathology. We identified RORB as a marker of selectively vulnerable excitatory neurons in the entorhinal cortex, and subsequently validated their depletion and selective susceptibility to neurofibrillary inclusions during disease progression using quantitative neuropathological methods. We also discovered an astrocyte subpopulation, likely representing reactive astrocytes, characterized by decreased expression of genes involved in homeostatic functions. Our characterization of selectively vulnerable neurons in AD paves the way for future mechanistic studies of selective vulnerability and potential therapeutic strategies for enhancing neuronal resilience.
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Background: The pallidofugal pathways are classically subdivided into ansa lenticularis, lenticular fasciculus, and subthalamic fasciculus. In addition to these three subsystems, we characterize an anatomical structure that connects the... more
Background: The pallidofugal pathways are classically subdivided into ansa lenticularis, lenticular fasciculus, and subthalamic fasciculus. In addition to these three subsystems, we characterize an anatomical structure that connects the antero-medial pole of the subthalamic nucleus to the ventral portions of the pallidum, both related to limbic processing of information. This bundle has been previously considered to form a part of the ansa lenticularis, however, it shows striking differences on histology and MRI features compared to the ansa lenticularis, and therefore we suggest to denominate it ansa subthalamica. Objectives: To describe the ansa subthalamica as a different structure than the ansa lenticularis, that can be recognized by different methods (histology, high-field MRI and connectome tractography), including current 3T clinical imaging. Methods: A complete human brain was histologically processed and submitted to registration procedures to correct for tissue deformation...
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Chorea-acanthocytosis (ChAc) and Huntington's disease (HD) are neurodegenerative conditions that share clinical and neuropathological features, despite their distinct genetic etiologies. In order to compare these neuropathologies,... more
Chorea-acanthocytosis (ChAc) and Huntington's disease (HD) are neurodegenerative conditions that share clinical and neuropathological features, despite their distinct genetic etiologies. In order to compare these neuropathologies, serial gallocyanin-stained brain sections from three subjects with ChAc were analyzed and compared with our previous studies of eight HD cases, in addition to three hemispheres from two male controls. Astrogliosis was much greater in the ChAc striatum, as compared to that found in HD, with dramatic increase in total striatal glia numbers and the number of glia per striatal neuron. Striatal astrocytes are most likely derived from the striatal subependymal layer in ChAc, which showed massive proliferation. The thalamic centromedian-parafascicular complex is reciprocally connected to the striatum and is more heavily affected in HD than in ChAc. The distinct patterns of selective vulnerability and gliosis observed in HD and ChAc challenge simplistic views ...
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The human brainstem is involved in the regulation of the sleep/waking cycle and normal sleep architectonics and is crucial for the performance of a variety of somatomotor, vital autonomic, oculomotor, vestibular, auditory, ingestive and... more
The human brainstem is involved in the regulation of the sleep/waking cycle and normal sleep architectonics and is crucial for the performance of a variety of somatomotor, vital autonomic, oculomotor, vestibular, auditory, ingestive and somatosensory functions. It harbors the origins of the ascending dopaminergic, cholinergic, noradrenergic, serotonergic systems, as well the home base of the descending serotonergic system. In contrast to the cerebral cortex the affection of the brainstem in Alzheimer's disease (AD) by the neurofibrillary or tau cytoskeletal pathology was recognized only approximately fourty years ago in initial brainstem studies. Detailed pathoanatomical investigations of silver stained or tau immunostained brainstem tissue sections revealed nerve cell loss and prominent AD-related cytoskeletal changes in the raphe nuclei, locus coeruleus, and in the compact parts of the substantia nigra and pedunculopontine nucleus. An additional conspicuous AD-related cytoskel...
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Brain function in normal aging and neurological diseases has long been a subject of interest. With current technology, it is possible to go beyond descriptive analyses to characterize brain cell populations at the molecular level.... more
Brain function in normal aging and neurological diseases has long been a subject of interest. With current technology, it is possible to go beyond descriptive analyses to characterize brain cell populations at the molecular level. However, the brain comprises over 100 billion highly specialized cells, and it is a challenge to discriminate different cell groups for analyses. Isolating intact neurons is not feasible with traditional methods, such as tissue homogenization techniques. The advent of laser microdissection techniques promises to overcome previous limitations in the isolation of specific cells. Here, we provide a detailed protocol for isolating and analyzing neurons from postmortem human brain tissue samples. We describe a workflow for successfully freezing, sectioning and staining tissue for laser microdissection. This protocol was validated by mass spectrometric analysis. Isolated neurons can also be employed for western blotting or PCR. This protocol will enable further ...
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The antispastic agent and N-methyl-D-aspartate (NMDA) receptor antagonist memantine has recently been proposed as a neuroprotective drug for use in patients with dementia syndromes with primarily temporal lobe pathology, e.g. senile... more
The antispastic agent and N-methyl-D-aspartate (NMDA) receptor antagonist memantine has recently been proposed as a neuroprotective drug for use in patients with dementia syndromes with primarily temporal lobe pathology, e.g. senile dementia of Alzheimer type or dementia in Parkinson's disease. In a quantitative autoradiographic study in human post mortem hippocampus, memantine was able to inhibit binding of the noncompetitive NMDA-antagonist [3H]MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine maleate) with inhibition constants between 3 and 10 microM, being about a factor of 10 more potent than the dissociative anaesthetic and NMDA receptor antagonist (+/-)ketamine. As these inhibition constants are well within the therapeutic concentration range of memantine, antagonism of endogenous glutamate at limbic NMDA receptors may be one molecular mechanism by which memantine is beneficial in dementia syndromes.
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Deposits of abnormal Tau inclusions in the brain are a well-known Alzheimer's disease (AD) pathological feature and are the best predictor for neuronal loss and clinical decline. As such, Tau is a potential in-vivo imaging biomarker... more
Deposits of abnormal Tau inclusions in the brain are a well-known Alzheimer's disease (AD) pathological feature and are the best predictor for neuronal loss and clinical decline. As such, Tau is a potential in-vivo imaging biomarker that could leverage earlier AD diagnosis. In fact, there are several research initiatives to develop PET tracers for imaging Tau in the human brain. Validation of such studies, however, is only reliably performed using histological data, where Tau inclusion can be accurately located. Manually locating and segmenting Tau in such images is unfeasible since a whole human brain slice, at the adequate resolution, spans several Gigabytes of data and carries thousands of inclusions. In this study, we present our preliminary results on using convolutional neural networks (CNN) to automatically locate and segment Tau in whole human brain histological slides. CNNs are multi-layered representation-learning methods capable of automatically discover unknown patte...
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Neurobiological models have provided consistent evidence of the involvement of cortical-subcortical circuitry in obsessive-compulsive disorder (OCD). The orbitofrontal cortex (OFC), involved in motivation and emotional responses, is an... more
Neurobiological models have provided consistent evidence of the involvement of cortical-subcortical circuitry in obsessive-compulsive disorder (OCD). The orbitofrontal cortex (OFC), involved in motivation and emotional responses, is an important regulatory node within this circuitry. However, OFC abnormalities at the cellular level have so far not been studied. To address this question, we have recruited a total of seven senior individuals from the Sao Paulo Autopsy Services who were diagnosed with OCD after an extensive post-mortem clinical evaluation with their next of kin. Patients with cognitive impairment were excluded. The OCD cases were age- and sex-matched with 7 control cases and a total of 14 formalin-fixed, serially cut, and gallocyanin-stained hemispheres (7 subjects with OCD and 7 controls) were analyzed stereologically. We estimated laminar neuronal density, volume of the anteromedial (AM), medial orbitofrontal (MO), and anterolateral (AL) areas of the OFC. We found st...
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The brainstem nuclei of the reticular formation (RF) are critical for regulating homeostasis, behavior, and cognition. RF degenerates in tauopathies including Alzheimer disease (AD), progressive supranuclear palsy (PSP), and corticobasal... more
The brainstem nuclei of the reticular formation (RF) are critical for regulating homeostasis, behavior, and cognition. RF degenerates in tauopathies including Alzheimer disease (AD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). Although the burden of phopho-tau inclusion is high across these diseases, suggesting a similar vulnerability pattern, a distinct RF-associated clinical phenotype in these diseases indicates the opposite. To compare patterns of RF selective vulnerability to tauopathies, we analyzed 5 RF nuclei in tissue from 14 AD, 14 CBD, 10 PSP, and 3 control cases. Multidimensional quantitative analysis unraveled discernable differences on how these nuclei are vulnerable to AD, CBD, and PSP. For instance, PSP and CBD accrued more tau inclusions than AD in locus coeruleus, suggesting a lower vulnerability to AD. However, locus coeruleus neuronal loss in AD was so extreme that few neurons remained to develop aggregates. Likewise, tau burden in g...
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Stereotaxy is based on the precise image-guided spatial localization of targets within the human brain. Even with the recent advances in MRI technology, histological examination renders different (and complementary) information of the... more
Stereotaxy is based on the precise image-guided spatial localization of targets within the human brain. Even with the recent advances in MRI technology, histological examination renders different (and complementary) information of the nervous tissue. Although several maps have been selected as a basis for correlating imaging results with the anatomical locations of sub-cortical structures, technical limitations interfere in a point-to-point correlation between imaging and anatomy due to the lack of precise correction for post-mortem tissue deformations caused by tissue fixation and processing. We present an alternative method to parcellate human brain cytoarchitectural regions, minimizing deformations caused by post-mortem and tissue-processing artifacts and enhancing segmentation by means of modified high thickness histological techniques and registration with MRI of the same specimen and into MNI space (ICBM152). A three-dimensional (3D) histological atlas of the human thalamus, b...
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The basal forebrain complex (BFC) is a small but intricate structure. Its organization and function is hard to investigate using conventional methods, especially in humans. By combining new methods of research we present a comprehensive... more
The basal forebrain complex (BFC) is a small but intricate structure. Its organization and function is hard to investigate using conventional methods, especially in humans. By combining new methods of research we present a comprehensive overview of this complex, in order to better understand its function in normal and diseased brains. Methods: The right and left BFC of a 29-year-old male were reconstructed from gallcocyanin (Nissl) stained 440 mm-thick serial horizontal sections by using advanced computer-assisted 3D reconstruction software. Results: The reconstructed components in the present case include Ch2, Ch3, Ch4am-al, Ch4i, Ch4p, juxtacommissural, Ayala's medial (subpallidal) and lateral (periputaminal) subnuclei. These components are arranged in an arch-like course mainly beneath the anterior commissure. The bilateral volume of all subnuclei was 99.06 mm³, the left side accounting for 48.05 mm³. Some of the subnuclei exhibited volume asymmetry indices varying from 28.3 ...
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Clarifying the mechanisms connecting neurofibrillary tangle (NFT) neurotoxicity to neuronal dysfunction in humans is likely to be pivotal for developing effective treatments for... more
Clarifying the mechanisms connecting neurofibrillary tangle (NFT) neurotoxicity to neuronal dysfunction in humans is likely to be pivotal for developing effective treatments for Alzheimer's disease (AD). To model the temporal progression of AD in humans, we used a collection of brains with controls and individuals from each Braak stage to quantitatively investigate the correlation between intraneuronal caspase activation or macroautophagy markers, NFT burden, and neuronal loss, in the dorsal raphe nucleus and locus coeruleus, the earliest vulnerable areas to NFT accumulation. We fit linear regressions with each count as outcomes, with Braak score and age as the predictors. In progressive Braak stages, intraneuronal active caspase-6 positivity increases both alone and overlapping with NFTs. Likewise, the proportion of NFT-bearing neurons showing autophagosomes increases. Overall, caspases may be involved in upstream cascades in AD and are associated with higher NFTs. Macroautophagy changes correlate with increasing NFT burden from early AD stages.
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Alzheimer's disease (AD) represents the most frequent neurodegenerative disease of the human brain worldwide. Currently practiced treatment strategies for AD only include some less effective symptomatic therapeutic interventions,... more
Alzheimer's disease (AD) represents the most frequent neurodegenerative disease of the human brain worldwide. Currently practiced treatment strategies for AD only include some less effective symptomatic therapeutic interventions, which unable to counteract the disease course of AD. New therapeutic attempts aimed to prevent, reduce, or remove the extracellular depositions of the amyloid-β protein did not elicit beneficial effects on cognitive deficits or functional decline of AD. In view of the failure of these amyloid-β-based therapeutic trials and the close correlation between the brain pathology of the cytoskeletal tau protein and clinical AD symptoms, therapeutic attention has since shifted to the tau cytoskeletal protein as a novel drug target. The abnormal hyperphosphorylation and intraneuronal aggregation of this protein are early events in the evolution of the AD-related neurofibrillary pathology, and the brain spread of the AD-related tau aggregation pathology may possib...
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Huntington’s disease (HD) is a severe, autosomal dominantly inherited, gradually worsening neurological disorder, the clinical features of which were first described in 1863 by Irving W. Lyon and with additional details, in 1872, by... more
Huntington’s disease (HD) is a severe, autosomal dominantly inherited, gradually worsening neurological disorder, the clinical features of which were first described in 1863 by Irving W. Lyon and with additional details, in 1872, by George Huntington. Progress in molecular biological research has shown that HD is caused by meiotically unstable CAG-repeats in the mutated HD gene (the so-called IT 15 gene) on chromosome 4p16.3, which encodes the mutated protein huntingtin (Htt). This monograph provides a survey of the stepwise progress in neuropathological HD research made during a time period of more than hundred years, the currently known neuropathological hallmarks of HD, as well as their pathogenic and clinical relevance. Starting with the initial descriptions of the progressive degeneration of the neostriatum (i.e., caudate nucleus and putamen) as one of the key events in HD, the worldwide practiced Vonsattel HD grading system of striatal neurodegeneration will be outlined. Corre...
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Human hippocampal area Cornu Ammonis (CA) 1 is one of the first fields in the human telencephalon showing Alzheimer disease (AD)-specific neuropathological changes. In contrast, CA2 and CA3 are far later affected pointing to functional... more
Human hippocampal area Cornu Ammonis (CA) 1 is one of the first fields in the human telencephalon showing Alzheimer disease (AD)-specific neuropathological changes. In contrast, CA2 and CA3 are far later affected pointing to functional differences, which may be accompanied by differences in proteome endowment and changes. Human pyramidal cell layers of hippocampal areas CA1, CA2, and CA3 from neurologically unaffected individuals were excised using laser microdissection. The proteome of each individual sample was analyzed and differentially abundant proteins were validated by immuno-histochemistry. Comparison of CA1 to CA2 revealed 223, CA1 to CA3 197 proteins with differential abundance, among them we found motor proteins MYO5A and DYNC1H1. Extension of the study to human hippocampus slices from AD patients revealed extensive depletion of these proteins in CA1 area compared to unaffected controls. High abundance of motor proteins in pyramidal cell layers CA1 compared to CA2 and CA3...