1
|
Casciano F, Zauli E, Celeghini C, Caruso L, Gonelli A, Zauli G, Pignatelli A. Retinal Alterations Predict Early Prodromal Signs of Neurodegenerative Disease. Int J Mol Sci 2024; 25:1689. [PMID: 38338966 PMCID: PMC10855697 DOI: 10.3390/ijms25031689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/25/2024] [Accepted: 01/27/2024] [Indexed: 02/12/2024] Open
Abstract
Neurodegenerative diseases are an increasingly common group of diseases that occur late in life with a significant impact on personal, family, and economic life. Among these, Alzheimer's disease (AD) and Parkinson's disease (PD) are the major disorders that lead to mild to severe cognitive and physical impairment and dementia. Interestingly, those diseases may show onset of prodromal symptoms early after middle age. Commonly, the evaluation of these neurodegenerative diseases is based on the detection of biomarkers, where functional and structural magnetic resonance imaging (MRI) have shown a central role in revealing early or prodromal phases, although it can be expensive, time-consuming, and not always available. The aforementioned diseases have a common impact on the visual system due to the pathophysiological mechanisms shared between the eye and the brain. In Parkinson's disease, α-synuclein deposition in the retinal cells, as well as in dopaminergic neurons of the substantia nigra, alters the visual cortex and retinal function, resulting in modifications to the visual field. Similarly, the visual cortex is modified by the neurofibrillary tangles and neuritic amyloid β plaques typically seen in the Alzheimer's disease brain, and this may reflect the accumulation of these biomarkers in the retina during the early stages of the disease, as seen in postmortem retinas of AD patients. In this light, the ophthalmic evaluation of retinal neurodegeneration could become a cost-effective method for the early diagnosis of those diseases, overcoming the limitations of functional and structural imaging of the deep brain. This analysis is commonly used in ophthalmic practice, and interest in it has risen in recent years. This review will discuss the relationship between Alzheimer's disease and Parkinson's disease with retinal degeneration, highlighting how retinal analysis may represent a noninvasive and straightforward method for the early diagnosis of these neurodegenerative diseases.
Collapse
Affiliation(s)
- Fabio Casciano
- Department of Translational Medicine and LTTA Centre, University of Ferrara, 44121 Ferrara, Italy
| | - Enrico Zauli
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Claudio Celeghini
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Lorenzo Caruso
- Department of Environment and Prevention Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Arianna Gonelli
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Giorgio Zauli
- Research Department, King Khaled Eye Specialistic Hospital, Riyadh 12329, Saudi Arabia
| | - Angela Pignatelli
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44124 Ferrara, Italy
| |
Collapse
|
2
|
L'Esperance OJ, McGhee J, Davidson G, Niraula S, Smith AS, Sosunov AA, Yan SS, Subramanian J. Functional Connectivity Favors Aberrant Visual Network c-Fos Expression Accompanied by Cortical Synapse Loss in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2024; 101:111-131. [PMID: 39121131 DOI: 10.3233/jad-240776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2024]
Abstract
Background While Alzheimer's disease (AD) has been extensively studied with a focus on cognitive networks, visual network dysfunction has received less attention despite compelling evidence of its significance in AD patients and mouse models. We recently reported c-Fos and synaptic dysregulation in the primary visual cortex of a pre-amyloid plaque AD-model. Objective We test whether c-Fos expression and presynaptic density/dynamics differ in cortical and subcortical visual areas in an AD-model. We also examine whether aberrant c-Fos expression is inherited through functional connectivity and shaped by light experience. Methods c-Fos+ cell density, functional connectivity, and their experience-dependent modulation were assessed for visual and whole-brain networks in both sexes of 4-6-month-old J20 (AD-model) and wildtype (WT) mice. Cortical and subcortical differences in presynaptic vulnerability in the AD-model were compared using ex vivo and in vivo imaging. Results Visual cortical, but not subcortical, networks show aberrant c-Fos expression and impaired experience-dependent modulation. The average functional connectivity of a brain region in WT mice significantly predicts aberrant c-Fos expression, which correlates with impaired experience-dependent modulation in the AD-model. We observed a subtle yet selective weakening of excitatory visual cortical synapses. The size distribution of cortical boutons in the AD-model is downscaled relative to those in WT mice, suggesting a synaptic scaling-like adaptation of bouton size. Conclusions Visual network structural and functional disruptions are biased toward cortical regions in pre-plaque J20 mice, and the cellular and synaptic dysregulation in the AD-model represents a maladaptive modification of the baseline physiology seen in WT conditions.
Collapse
Affiliation(s)
- Oliver J L'Esperance
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, USA
| | - Joshua McGhee
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, USA
| | - Garett Davidson
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, USA
| | - Suraj Niraula
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, USA
| | - Adam S Smith
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, USA
| | - Alexandre A Sosunov
- Department of Neurosurgery, Columbia University Medical Center, New York, NY, USA
| | - Shirley Shidu Yan
- Department of Neurosurgery, Columbia University Medical Center, New York, NY, USA
| | - Jaichandar Subramanian
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, USA
| |
Collapse
|
3
|
Zhang NK, Zhang SK, Zhang LI, Tao HW, Zhang GW. Sensory processing deficits and related cortical pathological changes in Alzheimer's disease. Front Aging Neurosci 2023; 15:1213379. [PMID: 37649717 PMCID: PMC10464619 DOI: 10.3389/fnagi.2023.1213379] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 07/24/2023] [Indexed: 09/01/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder primarily affecting cognitive functions. However, sensory deficits in AD start to draw attention due to their high prevalence and early onsets which suggest that they could potentially serve as diagnostic biomarkers and even contribute to the disease progression. This literature review examines the sensory deficits and cortical pathological changes observed in visual, auditory, olfactory, and somatosensory systems in AD patients, as well as in various AD animal models. Sensory deficits may emerge at the early stages of AD, or even precede the cognitive decline, which is accompanied by cortical pathological changes including amyloid-beta deposition, tauopathy, gliosis, and alterations in neuronal excitability, synaptic inputs, and functional plasticity. Notably, these changes are more pronounced in sensory association areas and superficial cortical layers, which may explain the relative preservation of basic sensory functions but early display of deficits of higher sensory functions. We propose that sensory impairment and the progression of AD may establish a cyclical relationship that mutually perpetuates each condition. This review highlights the significance of sensory deficits with or without cortical pathological changes in AD and emphasizes the need for further research to develop reliable early detection and intervention through sensory systems.
Collapse
Affiliation(s)
- Nicole K. Zhang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Selena K. Zhang
- Biomedical Engineering Program, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States
| | - Li I. Zhang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Department of Physiology & Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Huizhong W. Tao
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Department of Physiology & Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Guang-Wei Zhang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| |
Collapse
|
4
|
Latina V, De Introna M, Caligiuri C, Loviglio A, Florio R, La Regina F, Pignataro A, Ammassari-Teule M, Calissano P, Amadoro G. Immunotherapy with Cleavage-Specific 12A12mAb Reduces the Tau Cleavage in Visual Cortex and Improves Visuo-Spatial Recognition Memory in Tg2576 AD Mouse Model. Pharmaceutics 2023; 15:pharmaceutics15020509. [PMID: 36839831 PMCID: PMC9965010 DOI: 10.3390/pharmaceutics15020509] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/25/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Tau-targeted immunotherapy is a promising approach for treatment of Alzheimer's disease (AD). Beyond cognitive decline, AD features visual deficits consistent with the manifestation of Amyloid β-protein (Aβ) plaques and neurofibrillary tangles (NFT) in the eyes and higher visual centers, both in animal models and affected subjects. We reported that 12A12-a monoclonal cleavage-specific antibody (mAb) which in vivo neutralizes the neurotoxic, N-terminal 20-22 kDa tau fragment(s)-significantly reduces the retinal accumulation in Tg(HuAPP695Swe)2576 mice of both tau and APP/Aβ pathologies correlated with local inflammation and synaptic deterioration. Here, we report the occurrence of N-terminal tau cleavage in the primary visual cortex (V1 area) and the beneficial effect of 12A12mAb treatment on phenotype-associated visuo-spatial deficits in this AD animal model. We found out that non-invasive administration of 12 A12mAb markedly reduced the pathological accumulation of both truncated tau and Aβ in the V1 area, correlated to significant improvement in visual recognition memory performance along with local increase in two direct readouts of cortical synaptic plasticity, including the dendritic spine density and the expression level of activity-regulated cytoskeleton protein Arc/Arg3.1. Translation of these findings to clinical therapeutic interventions could offer an innovative tau-directed opportunity to delay or halt the visual impairments occurring during AD progression.
Collapse
Affiliation(s)
- Valentina Latina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Margherita De Introna
- Institute of Translational Pharmacology (IFT), National Research Council (CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
- IRCCS Santa Lucia Foundation (FSL), Centro di Ricerca Europeo sul Cervello (CERC), Via Fosso del Fiorano 64-65, 00143 Rome, Italy
| | - Chiara Caligiuri
- IRCCS Santa Lucia Foundation (FSL), Centro di Ricerca Europeo sul Cervello (CERC), Via Fosso del Fiorano 64-65, 00143 Rome, Italy
| | - Alessia Loviglio
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Rita Florio
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Federico La Regina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Annabella Pignataro
- Institute of Translational Pharmacology (IFT), National Research Council (CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
- IRCCS Santa Lucia Foundation (FSL), Centro di Ricerca Europeo sul Cervello (CERC), Via Fosso del Fiorano 64-65, 00143 Rome, Italy
| | - Martine Ammassari-Teule
- IRCCS Santa Lucia Foundation (FSL), Centro di Ricerca Europeo sul Cervello (CERC), Via Fosso del Fiorano 64-65, 00143 Rome, Italy
- Institute of Biochemistry and Cell Biology (IBBC), National Research Council (CNR), Via Ercole Ramarini 32, 00015 Rome, Italy
| | - Pietro Calissano
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Giuseppina Amadoro
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
- Institute of Translational Pharmacology (IFT), National Research Council (CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
- Correspondence: ; Tel.: +39-06-49255252
| |
Collapse
|
5
|
Hao X, Zhang W, Jiao B, Yang Q, Zhang X, Chen R, Wang X, Xiao X, Zhu Y, Liao W, Wang D, Shen L. Correlation between retinal structure and brain multimodal magnetic resonance imaging in patients with Alzheimer's disease. Front Aging Neurosci 2023; 15:1088829. [PMID: 36909943 PMCID: PMC9992546 DOI: 10.3389/fnagi.2023.1088829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 02/06/2023] [Indexed: 02/24/2023] Open
Abstract
Background The retina imaging and brain magnetic resonance imaging (MRI) can both reflect early changes in Alzheimer's disease (AD) and may serve as potential biomarker for early diagnosis, but their correlation and the internal mechanism of retinal structural changes remain unclear. This study aimed to explore the possible correlation between retinal structure and visual pathway, brain structure, intrinsic activity changes in AD patients, as well as to build a classification model to identify AD patients. Methods In the study, 49 AD patients and 48 healthy controls (HCs) were enrolled. Retinal images were obtained by optical coherence tomography (OCT). Multimodal MRI sequences of all subjects were collected. Spearman correlation analysis and multiple linear regression models were used to assess the correlation between OCT parameters and multimodal MRI findings. The diagnostic value of combination of retinal imaging and brain multimodal MRI was assessed by performing a receiver operating characteristic (ROC) curve. Results Compared with HCs, retinal thickness and multimodal MRI findings of AD patients were significantly altered (p < 0.05). Significant correlations were presented between the fractional anisotropy (FA) value of optic tract and mean retinal thickness, macular volume, macular ganglion cell layer (GCL) thickness, inner plexiform layer (IPL) thickness in AD patients (p < 0.01). The fractional amplitude of low frequency fluctuations (fALFF) value of primary visual cortex (V1) was correlated with temporal quadrant peripapillary retinal nerve fiber layer (pRNFL) thickness (p < 0.05). The model combining thickness of GCL and temporal quadrant pRNFL, volume of hippocampus and lateral geniculate nucleus, and age showed the best performance to identify AD patients [area under the curve (AUC) = 0.936, sensitivity = 89.1%, specificity = 87.0%]. Conclusion Our study demonstrated that retinal structure change was related to the loss of integrity of white matter fiber tracts in the visual pathway and the decreased LGN volume and functional metabolism of V1 in AD patients. Trans-synaptic axonal retrograde lesions may be the underlying mechanism. Combining retinal imaging and multimodal MRI may provide new insight into the mechanism of retinal structural changes in AD and may serve as new target for early auxiliary diagnosis of AD.
Collapse
Affiliation(s)
- Xiaoli Hao
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, China
| | - Weiwei Zhang
- Department of Radiology, Xiangya Hospital of Central South University, Changsha, China
| | - Bin Jiao
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China.,Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China.,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Qijie Yang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, China
| | - Xinyue Zhang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, China
| | - Ruiting Chen
- Department of Radiology, Xiangya Hospital of Central South University, Changsha, China
| | - Xin Wang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, China
| | - Xuewen Xiao
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, China
| | - Yuan Zhu
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, China
| | - Weihua Liao
- Department of Radiology, Xiangya Hospital of Central South University, Changsha, China
| | - Dongcui Wang
- Department of Radiology, Xiangya Hospital of Central South University, Changsha, China
| | - Lu Shen
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China.,Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China.,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
| |
Collapse
|
6
|
Nguyen HL, Linh HQ, Krupa P, La Penna G, Li MS. Amyloid β Dodecamer Disrupts the Neuronal Membrane More Strongly than the Mature Fibril: Understanding the Role of Oligomers in Neurotoxicity. J Phys Chem B 2022; 126:3659-3672. [PMID: 35580354 PMCID: PMC9150093 DOI: 10.1021/acs.jpcb.2c01769] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
The amyloid cascade
hypothesis states that senile plaques, composed
of amyloid β (Aβ) fibrils, play a key role in Alzheimer’s
disease (AD). However, recent experiments have shown that Aβ
oligomers are more toxic to neurons than highly ordered fibrils. The
molecular mechanism underlying this observation remains largely unknown.
One of the possible scenarios for neurotoxicity is that Aβ peptides
create pores in the lipid membrane that allow Ca2+ ions
to enter cells, resulting in a signal of cell apoptosis. Hence, one
might think that oligomers are more toxic due to their higher ability
to create ion channels than fibrils. In this work, we study the effect
of Aβ42 dodecamer and fibrils on a neuronal membrane, which
is similar to that observed in AD patients, using all-atom molecular
dynamics simulations. Due to short simulation times, we cannot observe
the formation of pores, but useful insight on the early events of
this process has been obtained. Namely, we showed that dodecamer distorts
the lipid membrane to a greater extent than fibrils, which may indicate
that ion channels can be more easily formed in the presence of oligomers.
Based on this result, we anticipate that oligomers are more toxic
than mature fibrils, as observed experimentally. Moreover, the Aβ–membrane
interaction was found to be governed by the repulsive electrostatic
interaction between Aβ and the ganglioside GM1 lipid. We calculated
the bending and compressibility modulus of the membrane in the absence
of Aβ and obtained good agreement with the experiment. We predict
that the dodecamer will increase the compressibility modulus but has
little effect on the bending modulus. Due to the weak interaction
with the membrane, fibrils insignificantly change the membrane elastic
properties.
Collapse
Affiliation(s)
- Hoang Linh Nguyen
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City 729110, Vietnam.,Ho Chi Minh City University of Technology (HCMUT), Ho Chi Minh City 740500, Vietnam.,Vietnam National University, Ho Chi Minh City 71300, Vietnam
| | - Huynh Quang Linh
- Ho Chi Minh City University of Technology (HCMUT), Ho Chi Minh City 740500, Vietnam.,Vietnam National University, Ho Chi Minh City 71300, Vietnam
| | - Pawel Krupa
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw 02-668, Poland
| | - Giovanni La Penna
- National Research Council of Italy (CNR), Institute for Chemistry of Organometallic Compounds (ICCOM), Florence 50019, Italy.,National Institute for Nuclear Physics (INFN), Section of Roma-Tor Vergata, Rome 00815, Italy
| | - Mai Suan Li
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw 02-668, Poland
| |
Collapse
|
7
|
Swerdlow RH, de Leon MJ, Marcus DL. Betahydroxybutyrate Consumption in Autopsy Brain Tissue from Alzheimer's Disease Subjects. J Alzheimers Dis Rep 2021; 5:135-141. [PMID: 33782666 PMCID: PMC7990458 DOI: 10.3233/adr-210002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: Alzheimer’s disease (AD) features perturbed brain glucose utilization, which could contribute to brain bioenergetic failure. This led some to consider using ketone bodies to enhance AD brain bioenergetics and treat AD. Objective: We evaluated the rate at which brain homogenates from persons with Alzheimer’s disease (AD) metabolize D-β-hydroxybutyrate (BHB). Methods: We homogenized pieces of temporal cortex from frozen autopsy brains obtained from recently deceased AD subjects (n = 4), and age-matched subjects that did not have clinical AD (n = 3). Measuring the rate of CO2 production that followed the introduction of radiolabeled BHB to the homogenates yielded a BHB utilization rate. Results: Compared to the control homogenates, the BHB-supported CO2 production rate was 66%lower in the AD homogenates (p < 0.05). Conclusions: AD brains can utilize BHB, albeit less robustly than control brains. In conjunction with a previous study that demonstrated reduced glucose utilization in AD brain homogenates, our BHB data provide further evidence of AD brain mitochondrial dysfunction or altered mitochondrial biology.
Collapse
Affiliation(s)
- Russell H Swerdlow
- University of Kansas Alzheimer's Disease Research Center, Fairway, KS, USA
| | | | - David L Marcus
- New York University Medical Center, New York City, NY, USA
| |
Collapse
|
8
|
The Retinal Inner Plexiform Synaptic Layer Mirrors Grey Matter Thickness of Primary Visual Cortex with Increased Amyloid β Load in Early Alzheimer's Disease. Neural Plast 2020; 2020:8826087. [PMID: 33014034 PMCID: PMC7525303 DOI: 10.1155/2020/8826087] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/19/2020] [Accepted: 08/24/2020] [Indexed: 11/17/2022] Open
Abstract
The retina may serve as putative window into neuropathology of synaptic loss in Alzheimer's disease (AD). Here, we investigated synapse-rich layers versus layers composed by nuclei/cell bodies in an early stage of AD. In addition, we examined the associations between retinal changes and molecular and structural markers of cortical damage. We recruited 20 AD patients and 17 healthy controls (HC). Combining optical coherence tomography (OCT), magnetic resonance (MR), and positron emission tomography (PET) imaging, we measured retinal and primary visual cortex (V1) thicknesses, along with V1 amyloid β (Aβ) retention ([11C]-PiB PET tracer) and neuroinflammation ([11C]-PK11195 PET tracer). We found that V1 showed increased amyloid-binding potential, in the absence of neuroinflammation. Although thickness changes were still absent, we identified a positive association between the synapse-rich inner plexiform layer (IPL) and V1 in AD. This retinocortical interplay might reflect changes in synaptic function resulting from Aβ deposition, contributing to early visual loss.
Collapse
|
9
|
Mavilio A, Sisto D, Prete F, Guadalupi V, Dammacco R, Alessio G. RE-PERG in early-onset Alzheimer's disease: A double-blind, electrophysiological pilot study. PLoS One 2020; 15:e0236568. [PMID: 32790788 PMCID: PMC7425894 DOI: 10.1371/journal.pone.0236568] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 07/08/2020] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To evaluate the ability of re-test pattern electroretinogram (RE-PERG), a non-invasive and fast steady-state PERG, to detect inner retinal bioelectric function anomalies in patients with early-onset Alzheimer's disease (AD). METHODS The study population consisted of 17 patients with AD-related mild cognitive impairment (MCI), 16 patients with vascular dementia (VD)-related MCI, both assessed using the neuropsychological Mini-Mental State Examination (MMSE) and by structural magnetic resonance imaging, and 19 healthy, age-matched normal controls (NC). All participants were visually asymptomatic, had normal or near-normal general cognitive functioning and no or minimal impairments in daily life activities. Visual field (VF) test, optical coherence tomography (OCT) and RE-PERG, sampled in five consecutive blocks of 130 events, were performed. RESULTS There was no statistically significant difference among the three groups with respect to age, VF parameters (mean and pattern standard deviations) and OCT parameters (ganglion cell complex thickness and retinal nerve fiber layer thickness). The mean amplitude in the RE-PERG was significantly lower, but only weakly in the AD group than in NC (p = 0.1) whereas the intrinsic variability of the 2nd harmonic phase was significantly higher in the AD group than in either the VD or NC group (p<0.001). CONCLUSIONS RE-PERG is altered in early-stage AD, showing a reduced amplitude with high intrinsic phase variability. It also allows the discrimination of AD from VD. A high intrinsic variability in the PERG signal, determined using RE-PERG, may thus be a new promising test for neurodegenerative diseases.
Collapse
Affiliation(s)
- Alberto Mavilio
- Social Health District, Glaucoma Center, Azienda Sanitaria Locale–Brindisi, Brindisi, Italy
| | - Dario Sisto
- Department of Neurosciences, Institute of Ophthalmology, University of Bari, Bari, Italy
| | - Florenza Prete
- Social Health District, Alzheimer Evaluation Units, Azienda Sanitaria Locale—Brindisi, Brindisi, Italy
| | - Viviana Guadalupi
- Social Health District, Alzheimer Evaluation Units, Azienda Sanitaria Locale—Brindisi, Brindisi, Italy
| | - Rosanna Dammacco
- Department of Neurosciences, Institute of Ophthalmology, University of Bari, Bari, Italy
| | - Giovanni Alessio
- Department of Neurosciences, Institute of Ophthalmology, University of Bari, Bari, Italy
| |
Collapse
|
10
|
Guo J, Xu C, Ni S, Zhang S, Li Q, Zeng P, Pi G, Liu E, Sun DS, Liu Y, Wang Z, Chen H, Yang Y, Wang JZ. Elevation of pS262-Tau and Demethylated PP2A in Retina Occurs Earlier than in Hippocampus During Hyperhomocysteinemia. J Alzheimers Dis 2020; 68:367-381. [PMID: 30775994 DOI: 10.3233/jad-180978] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hyperhomocysteinemia is an independent risk factor of Alzheimer's disease (AD), which is not diagnosed for many years before onset due to lack of peripherally detectable early biomarkers. Visual dysfunction is prevalent in AD patients and correlates with the severity of cognitive defects. Importantly, alterations in eyes can be non-invasively detected. To search for early biomarkers in eyes from high risk factors of AD, we injected homocysteine (Hcy) into the rats via vena caudalis for 3, 7, and 14 days, respectively, and characterized the chronological order of the AD-like pathologies appearing in retina and the hippocampus during the progression of hyperhomocysteinemia, and their correlations with cognitive impairment. We found that administration of Hcy for 14 days, but not 3 or 7 days, induced hyperhomocysteinemia, although a gradually increased blood Hcy level was detected. In retina and/or the hippocampus, significant loss of retinal ganglion cells and stenosis of retinal arteries with the AD-like tau and amyloid-β (Aβ) pathologies and memory deficit were shown only in the 14-day Hcy group. Interestingly, accumulation of Ser262 hyperphosphorylated tau (pS262-tau) but not Aβ with decreased methylation of protein phosphatase-2A catalytic subunit (M-PP2Ac) and increased de-methylated PP2Ac (DM-PP2Ac) was detected in retina of the 3-day Hcy group, in which the retinal pathologies were preceded by those of the hippocampus. These findings suggest that elevated pS262-tau and DM-PP2Ac and reduced M-PP2Ac in retina may serve as surveillance biomarkers for diagnosis of the hyperhomocysteinemia-induced AD in the early stage.
Collapse
Affiliation(s)
- Jing Guo
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Cheng Xu
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Shaozhou Ni
- Department of Emergency, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Shujuan Zhang
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Qihang Li
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical College, Zhejiang, China
| | - Peng Zeng
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Guilin Pi
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Enjie Liu
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Dong-Sheng Sun
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Yanchao Liu
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Zhouyi Wang
- Department of Neurology, Center Hospital of Huang Gang City, Hubei Province, PR China
| | - Haote Chen
- Department of Neurology, Center Hospital of Huang Gang City, Hubei Province, PR China
| | - Ying Yang
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| |
Collapse
|
11
|
Alves C, Jorge L, Canário N, Santiago B, Santana I, Castelhano J, Ambrósio AF, Bernardes R, Castelo-Branco M. Interplay Between Macular Retinal Changes and White Matter Integrity in Early Alzheimer's Disease. J Alzheimers Dis 2019; 70:723-732. [PMID: 31282416 PMCID: PMC6700635 DOI: 10.3233/jad-190152] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2019] [Indexed: 11/20/2022]
Abstract
This study aims to investigate the relationship between structural changes in the retina and white matter in the brain, in early Alzheimer's disease (AD). Twenty-three healthy controls (mean age = 63.4±7.5 years) and seventeen AD patients (mean age = 66.5±6.6 years) were recruited for this study. By combining two imaging techniques-optical coherence tomography and diffusion tensor imaging (DTI)-the association between changes in the thickness of individual retinal layers and white matter dysfunction in early AD was assessed. Retinal layers were segmented, and thickness measurements were obtained for each layer. DTI images were analyzed with a quantitative data-driven approach to evaluating whole-brain diffusion metrics, using tract-based spatial statistics. Diffusion metrics, such as fractional anisotropy, are markers for white matter integrity. Multivariate and partial correlation analyses evaluating the association between individual retinal layers thickness and diffusion metrics were performed. We found that axial diffusivity, indexing axonal integrity, was significantly reduced in AD (p = 0.016, Cohen's d = 1.004) while in the retina, only a marginal trend for significance was found for the outer plexiform layer (p = 0.084, Cohen's d = 0.688). Furthermore, a positive association was found in the AD group between fractional anisotropy and the inner nuclear layer thickness (p < 0.05, r = 0.419, corrected for multiple comparisons by controlling family-wise error rate). Our findings suggest that axonal damage in the brain dominates early on in this condition and shows an association with retinal structural integrity already at initial stages of AD. These findings are consistent with an early axonal degeneration mechanism in AD.
Collapse
Affiliation(s)
- Carolina Alves
- CIBIT – Coimbra Institute for Biomedical Imaging and Life Sciences, Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| | - Lília Jorge
- CIBIT – Coimbra Institute for Biomedical Imaging and Life Sciences, Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| | - Nádia Canário
- CIBIT – Coimbra Institute for Biomedical Imaging and Life Sciences, Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| | - Beatriz Santiago
- Department of Neurology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Isabel Santana
- Department of Neurology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - João Castelhano
- CIBIT – Coimbra Institute for Biomedical Imaging and Life Sciences, Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - António Francisco Ambrósio
- CNC.IBILI, University of Coimbra, Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Rui Bernardes
- CIBIT – Coimbra Institute for Biomedical Imaging and Life Sciences, Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Miguel Castelo-Branco
- CIBIT – Coimbra Institute for Biomedical Imaging and Life Sciences, Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| |
Collapse
|
12
|
Cerquera-Jaramillo MA, Nava-Mesa MO, González-Reyes RE, Tellez-Conti C, de-la-Torre A. Visual Features in Alzheimer's Disease: From Basic Mechanisms to Clinical Overview. Neural Plast 2018; 2018:2941783. [PMID: 30405709 PMCID: PMC6204169 DOI: 10.1155/2018/2941783] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 08/07/2018] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is the leading cause of dementia worldwide. It compromises patients' daily activities owing to progressive cognitive deterioration, which has elevated direct and indirect costs. Although AD has several risk factors, aging is considered the most important. Unfortunately, clinical diagnosis is usually performed at an advanced disease stage when dementia is established, making implementation of successful therapeutic interventions difficult. Current biomarkers tend to be expensive, insufficient, or invasive, raising the need for novel, improved tools aimed at early disease detection. AD is characterized by brain atrophy due to neuronal and synaptic loss, extracellular amyloid plaques composed of amyloid-beta peptide (Aβ), and neurofibrillary tangles of hyperphosphorylated tau protein. The visual system and central nervous system share many functional components. Thus, it is plausible that damage induced by Aβ, tau, and neuroinflammation may be observed in visual components such as the retina, even at an early disease stage. This underscores the importance of implementing ophthalmological examinations, less invasive and expensive than other biomarkers, as useful measures to assess disease progression and severity in individuals with or at risk of AD. Here, we review functional and morphological changes of the retina and visual pathway in AD from pathophysiological and clinical perspectives.
Collapse
Affiliation(s)
| | - Mauricio O. Nava-Mesa
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
| | - Rodrigo E. González-Reyes
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
| | - Carlos Tellez-Conti
- Escuela Superior de Oftalmología-Instituto Barraquer de América, Bogotá, Colombia
| | - Alejandra de-la-Torre
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
| |
Collapse
|
13
|
Madsen JB, Folke J, Pakkenberg B. Stereological Quantification of Plaques and Tangles in Neocortex from Alzheimer’s Disease Patients. J Alzheimers Dis 2018; 64:723-734. [DOI: 10.3233/jad-180105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Jes Buster Madsen
- Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital, Denmark
| | - Jonas Folke
- Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital, Denmark
| | - Bente Pakkenberg
- Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital, Denmark
- Institute of Clinical Medicine, Faculty of Health, University of Copenhagen, Denmark
| |
Collapse
|
14
|
von Bartheld CS. Myths and truths about the cellular composition of the human brain: A review of influential concepts. J Chem Neuroanat 2017; 93:2-15. [PMID: 28873338 DOI: 10.1016/j.jchemneu.2017.08.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 11/17/2022]
Abstract
Over the last 50 years, quantitative methodology has made important contributions to our understanding of the cellular composition of the human brain. Not all of the concepts that emerged from quantitative studies have turned out to be true. Here, I examine the history and current status of some of the most influential notions. This includes claims of how many cells compose the human brain, and how different cell types contribute and in what ratios. Additional concepts entail whether we lose significant numbers of neurons with normal aging, whether chronic alcohol abuse contributes to cortical neuron loss, whether there are significant differences in the quantitative composition of cerebral cortex between male and female brains, whether superior intelligence in humans correlates with larger numbers of brain cells, and whether there are secular (generational) changes in neuron number. Do changes in cell number or changes in ratios of cell types accompany certain diseases, and should all counting methods, even the theoretically unbiased ones, be validated and calibrated? I here examine the origin and the current status of major influential concepts, and I review the evidence and arguments that have led to either confirmation or refutation of such concepts. I discuss the circumstances, assumptions and mindsets that perpetuated erroneous views, and the types of technological advances that have, in some cases, challenged longstanding ideas. I will acknowledge the roles of key proponents of influential concepts in the sometimes convoluted path towards recognition of the true cellular composition of the human brain.
Collapse
Affiliation(s)
- Christopher S von Bartheld
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Mailstop 352, Reno, NV 89557, USA.
| |
Collapse
|
15
|
Bowns L, Beaudot WHA. Measuring Early Cortical Visual Processing in the Clinic. Iperception 2017; 8:2041669517702915. [PMID: 28567268 PMCID: PMC5438040 DOI: 10.1177/2041669517702915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We describe a mobile app that measures early cortical visual processing suitable for use in clinics. The app is called Component Extraction and Motion Integration Test (CEMIT). Observers are asked to respond to the direction of translating plaids that move in one of two very different directions. The plaids have been selected so that the plaid components move in one of the directions and the plaid pattern moves in the other direction. In addition to correctly responding to the pattern motion, observers demonstrate their ability to correctly extract the movement (and therefore the orientation) of the underlying components at specific spatial frequencies. We wanted to test CEMIT by seeing if we could replicate the broader tuning observed at low spatial frequencies for this type of plaid. Results from CEMIT were robust and successfully replicated this result for 50 typical observers. We envisage that it will be of use to researchers and clinicians by allowing them to investigate specific deficits at this fundamental level of cortical visual processing. CEMIT may also be used for screening purposes where visual information plays an important role, for example, air traffic controllers.
Collapse
|
16
|
Ding XQ, Maudsley AA, Sabati M, Sheriff S, Schmitz B, Schütze M, Bronzlik P, Kahl KG, Lanfermann H. Physiological neuronal decline in healthy aging human brain - An in vivo study with MRI and short echo-time whole-brain (1)H MR spectroscopic imaging. Neuroimage 2016; 137:45-51. [PMID: 27164326 DOI: 10.1016/j.neuroimage.2016.05.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/28/2016] [Accepted: 05/04/2016] [Indexed: 11/16/2022] Open
Abstract
Knowledge of physiological aging in healthy human brain is increasingly important for neuroscientific research and clinical diagnosis. To investigate neuronal decline in normal aging brain eighty-one healthy subjects aged between 20 and 70years were studied with MRI and whole-brain (1)H MR spectroscopic imaging. Concentrations of brain metabolites N-acetyl-aspartate (NAA), choline (Cho), total creatine (tCr), myo-inositol (mI), and glutamine+glutamate (Glx) in ratios to internal water, and the fractional volumes of brain tissue were estimated simultaneously in eight cerebral lobes and in cerebellum. Results demonstrated that an age-related decrease in gray matter volume was the largest contribution to changes in brain volume. Both lobar NAA and the fractional volume of gray matter (FVGM) decreased with age in all cerebral lobes, indicating that the decreased NAA was predominantly associated with decreased gray matter volume and neuronal density or metabolic activity. In cerebral white matter Cho, tCr, and mI increased with age in association with increased fractional volume, showing altered cellular membrane turn-over, energy metabolism, and glial activity in human aging white matter. In cerebellum tCr increased while brain tissue volume decreased with age, showing difference to cerebral aging. The observed age-related metabolic and microstructural variations suggest that physiological neuronal decline in aging human brain is associated with a reduction of gray matter volume and neuronal density, in combination with cellular aging in white matter indicated by microstructural alterations and altered energy metabolism in the cerebellum.
Collapse
Affiliation(s)
- Xiao-Qi Ding
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany.
| | - Andrew A Maudsley
- Department of Radiology, University of Miami School of Medicine, Miami, FL, USA
| | - Mohammad Sabati
- Department of Radiology, University of Miami School of Medicine, Miami, FL, USA; Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Sulaiman Sheriff
- Department of Radiology, University of Miami School of Medicine, Miami, FL, USA
| | - Birte Schmitz
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Martin Schütze
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Paul Bronzlik
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Kai G Kahl
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, Hannover, Germany
| | - Heinrich Lanfermann
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| |
Collapse
|
17
|
Lee S, Viqar F, Zimmerman ME, Narkhede A, Tosto G, Benzinger TLS, Marcus DS, Fagan AM, Goate A, Fox NC, Cairns NJ, Holtzman DM, Buckles V, Ghetti B, McDade E, Martins RN, Saykin AJ, Masters CL, Ringman JM, Ryan NS, Förster S, Laske C, Schofield PR, Sperling RA, Salloway S, Correia S, Jack C, Weiner M, Bateman RJ, Morris JC, Mayeux R, Brickman AM. White matter hyperintensities are a core feature of Alzheimer's disease: Evidence from the dominantly inherited Alzheimer network. Ann Neurol 2016; 79:929-39. [PMID: 27016429 DOI: 10.1002/ana.24647] [Citation(s) in RCA: 363] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/17/2016] [Accepted: 03/20/2016] [Indexed: 12/12/2022]
Abstract
OBJECTIVE White matter hyperintensities (WMHs) are areas of increased signal on T2-weighted magnetic resonance imaging (MRI) scans that most commonly reflect small vessel cerebrovascular disease. Increased WMH volume is associated with risk and progression of Alzheimer's disease (AD). These observations are typically interpreted as evidence that vascular abnormalities play an additive, independent role contributing to symptom presentation, but not core features of AD. We examined the severity and distribution of WMH in presymptomatic PSEN1, PSEN2, and APP mutation carriers to determine the extent to which WMH manifest in individuals genetically determined to develop AD. METHODS The study comprised participants (n = 299; age = 39.03 ± 10.13) from the Dominantly Inherited Alzheimer Network, including 184 (61.5%) with a mutation that results in AD and 115 (38.5%) first-degree relatives who were noncarrier controls. We calculated the estimated years from expected symptom onset (EYO) by subtracting the affected parent's symptom onset age from the participant's age. Baseline MRI data were analyzed for total and regional WMH. Mixed-effects piece-wise linear regression was used to examine WMH differences between carriers and noncarriers with respect to EYO. RESULTS Mutation carriers had greater total WMH volumes, which appeared to increase approximately 6 years before expected symptom onset. Effects were most prominent for the parietal and occipital lobe, which showed divergent effects as early as 22 years before estimated onset. INTERPRETATION Autosomal-dominant AD is associated with increased WMH well before expected symptom onset. The findings suggest the possibility that WMHs are a core feature of AD, a potential therapeutic target, and a factor that should be integrated into pathogenic models of the disease. Ann Neurol 2016;79:929-939.
Collapse
Affiliation(s)
- Seonjoo Lee
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY.,Division of Biostatistics, New York State Psychiatric Institute, New York, NY
| | - Fawad Viqar
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY.,Psychology Department, Fordham University, Bronx, NY
| | - Molly E Zimmerman
- Psychology Department, Fordham University, Bronx, NY.,Department of Neurology, Albert Einstein College of Medicine, Bronx, NY
| | - Atul Narkhede
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Giuseppe Tosto
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY.,Department of Neurology, Columbia University Medical Center and the New York Presbyterian Hospital, Columbia University, New York, NY
| | - Tammie L S Benzinger
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO
| | - Daniel S Marcus
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO
| | - Anne M Fagan
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | - Alison Goate
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Nick C Fox
- Dementia Research Center, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Nigel J Cairns
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - David M Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | - Virginia Buckles
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN
| | - Eric McDade
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | - Ralph N Martins
- Center of Excellence of Alzheimer's Disease Research and Care, School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, Australia
| | - Andrew J Saykin
- Indiana Alzheimer Disease Center and Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN
| | - Colin L Masters
- The Florey Institute, University of Melbourne, Parkville, Australia
| | - John M Ringman
- Memory and Aging Center, Keck School of Medicine of University of Southern California, Los Angeles, CA
| | - Natalie S Ryan
- Dementia Research Center, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Stefan Förster
- German Center for Neurodegenerative Diseases (DZNE) München and Tübingen and Department of Nuclear Medicine, Technische Universität München (TUM), Munich, Germany
| | - Christoph Laske
- German Center for Neurodegenerative Diseases (DZNE) and the Section for Dementia Research, Department of Cellular Neurology, Hertie Institute for Clinical Brain Research and Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Peter R Schofield
- Neuroscience Research Australia and University of New South Wales, Sydney, Australia
| | - Reisa A Sperling
- Center for Alzheimer Research and Treatment, Brigham and Women's Hospital and Massachusetts General Hospital, Boston, MA
| | - Stephen Salloway
- Butler Hospital and Department of Neurology, Alpert Medical School, Brown University, Providence, RI
| | - Stephen Correia
- Department of Psychiatry, Alpert Medical School, Brown University, Providence, RI
| | | | - Michael Weiner
- Department of Radiology and Biomedical Imaging, Center for Imaging of Neurodegenerative Diseases, San Francisco Veterans Affairs Medical Center and Departments of Psychiatry, Radiology, Medicine, and Neurology, University of California at San Francisco, San Francisco, CA
| | - Randall J Bateman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | - John C Morris
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | - Richard Mayeux
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY.,Department of Neurology, Columbia University Medical Center and the New York Presbyterian Hospital, Columbia University, New York, NY.,Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Adam M Brickman
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY.,Department of Neurology, Columbia University Medical Center and the New York Presbyterian Hospital, Columbia University, New York, NY.,Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY
| | | |
Collapse
|
18
|
Coppola G, Di Renzo A, Ziccardi L, Martelli F, Fadda A, Manni G, Barboni P, Pierelli F, Sadun AA, Parisi V. Optical Coherence Tomography in Alzheimer's Disease: A Meta-Analysis. PLoS One 2015; 10:e0134750. [PMID: 26252902 PMCID: PMC4529274 DOI: 10.1371/journal.pone.0134750] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/13/2015] [Indexed: 12/24/2022] Open
Abstract
Background Alzheimer’s disease (AD) is a neurodegenerative disorder, which is likely to start as mild cognitive impairment (MCI) several years before the its full-blown clinical manifestation. Optical coherence tomography (OCT) has been used to detect a loss in peripapillary retina nerve fiber layer (RNFL) and a reduction in macular thickness and volume of people affected by MCI or AD. Here, we performed an aggregate meta-analysis combining results from different studies. Methods and Findings Data sources were case-control studies published between January 2001 and August 2014 (identified through PubMed and Google Scholar databases) that examined the RNFL thickness by means of OCT in AD and MCI patients compared with cognitively healthy controls. Results 11 studies were identified, including 380 patients with AD, 68 with MCI and 293 healthy controls (HC). The studies suggest that the mean RNFL thickness is reduced in MCI (weighted mean differences in μm, WMD = -13.39, 95% CI: -17.34 to -9.45, p = 0.031) and, even more so, in AD (WMD = -15.95, 95% CI: -21.65 to -10.21, p<0.0001) patients compared to HC. RNFL in the 4 quadrants were all significantly thinner in AD superior (superior WMD = -24.0, 95% CI: -34.9 to -13.1, p<0.0001; inferior WMD = -20.8, 95% CI: -32.0 to -9.7, p<0.0001; nasal WMD = -14.7, 95% CI: -23.9 to -5.5, p<0.0001; and temporal WMD = -10.7, 95% CI: -19.9 to -1.4, p<0.0001); the same significant reduction in quadrant RNFL was observed in MCI patients compared with HC (Inferior WMD = -20.22, 95% CI: -30.41 to -10.03, p = 0.0001; nasal WMD = -7.4, 95% CI: -10.08 to -4.7, p = 0.0000; and temporal WMD = -6.88, 95% CI: -12.62 to -1.13, p = 0.01), with the exception of superior quadrant (WMD = -19.45, 95% CI: -40.23 to 1.32, p = 0.06). Conclusion Results from the meta-analysis support the important role of OCT for RNFL analysis in monitoring the progression of AD and in assessing the effectiveness of purported AD treatments.
Collapse
Affiliation(s)
- Gianluca Coppola
- G.B. Bietti Foundation-IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Rome, Italy
- * E-mail:
| | - Antonio Di Renzo
- G.B. Bietti Foundation-IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Rome, Italy
| | - Lucia Ziccardi
- G.B. Bietti Foundation-IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Rome, Italy
| | - Francesco Martelli
- Istituto Superiore di Sanità, Dipartimento Tecnologie e Salute, Rome, Italy
| | - Antonello Fadda
- Istituto Superiore di Sanità, Dipartimento Tecnologie e Salute, Rome, Italy
| | - Gianluca Manni
- Tor Vergata University of Rome, Department of Clinical Sciences and Translation Medicine; Rome, Italy
| | - Piero Barboni
- IRCCS Istituto Scientifico San Raffaele, Milan, Italy
| | - Francesco Pierelli
- Sapienza University of Rome Polo Pontino, Department of Medico-Surgical Sciences and Biotechnologies, Latina, Italy
- IRCCS-Neuromed, Pozzilli (IS), Italy
| | - Alfredo A. Sadun
- Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Vincenzo Parisi
- G.B. Bietti Foundation-IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Rome, Italy
| |
Collapse
|
19
|
Vision function abnormalities in Alzheimer disease. Surv Ophthalmol 2014; 59:414-33. [DOI: 10.1016/j.survophthal.2013.10.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 09/28/2013] [Accepted: 10/01/2013] [Indexed: 12/16/2022]
|
20
|
Honorio J, Tomasi D, Goldstein RZ, Leung HC, Samaras D. Can a single brain region predict a disorder? IEEE TRANSACTIONS ON MEDICAL IMAGING 2012; 31:2062-2072. [PMID: 22752119 DOI: 10.1109/tmi.2012.2206047] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We perform prediction of diverse disorders (Cocaine Use, Schizophrenia and Alzheimers disease) in unseen subjects from brain fMRI. First, we show that for multi-subject prediction of simple cognitive states (e.g. motor vs. calculation and reading), voxels-as-features methods produce clusters that are similar for different leave-one-subject-out folds; while for group classification (e.g. cocaine addicted vs. control subjects), voxels are scattered and less stable. Therefore, we chose to use a single region per experimental condition and a majority vote classifier. Interestingly, our method outperforms state-of-the-art techniques. Our method can integrate multiple experimental conditions and successfully predict disorders in unseen subjects (leave-one-subjectout generalization accuracy: 89.3% and 90.9% for Cocaine Use, 96.4% for Schizophrenia and 81.5% for Alzheimers disease). Our experimental results not only span diverse disorders, but also different experimental designs (block design and event related tasks), facilities, magnetic fields (1.5Tesla, 3Tesla, 4Tesla) and speed of acquisition (interscan interval from 1600ms to 3500ms). We further argue that our method produces a meaningful low dimensional representation that retains discriminability.
Collapse
|
21
|
Saavedra C, Iglesias J, Olivares EI. Event-Related Potentials Elicited By Face Identity Processing In Elderly Adults With Cognitive Impairment. Exp Aging Res 2012; 38:220-45. [DOI: 10.1080/0361073x.2012.660057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
22
|
Collins CE. Variability in neuron densities across the cortical sheet in primates. BRAIN, BEHAVIOR AND EVOLUTION 2011; 78:37-50. [PMID: 21691046 DOI: 10.1159/000327319] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The function of any area of the brain is a product of its unique population of neurons and nonneurons and their local and long-range connectional architecture. At the present time, we have inadequate data about numbers of neurons and the distribution patterns of neurons in the cortex and other parts of the brain. Numbers and densities of neurons and nonneurons provide the foundation for the assembly of a cortical and whole-brain neuronal network, yet the majority of studies reporting neuron densities for the primate cortex estimate the number of neurons in the cortex as a whole or in specific areas for comparisons between treatment groups or species. While this is valuable information for studies of scaling or comparative studies of specific pathways or functions, a more detailed examination of cell and neuron number distribution across the entire cortical expanse is needed. Two studies reviewed here use the isotropic fractionator method for the determination of cell and neuron numbers to investigate the distribution of cells and neurons across the entire cortical sheet of 4 primate species, taking into consideration cortical areal boundaries. Neuron and total cell numbers were found to vary as much as 5 times between different functional areas across the cortical sheet. Numbers were also variable across representational zones within cortical areas like V1 and S1. The overall distribution of cells and neurons appears to be conserved across the species examined, suggesting a common plan for cell distribution in primates, with more areas of high neuron density in macaques and baboons compared to the smaller and less differentiated cortex of prosimian galagos and the New World owl monkey.
Collapse
|
23
|
Hundelt M, Fath T, Selle K, Oesterwind K, Jordan J, Schultz C, Götz J, von Engelhardt J, Monyer H, Lewejohann L, Sachser N, Bakota L, Brandt R. Altered phosphorylation but no neurodegeneration in a mouse model of tau hyperphosphorylation. Neurobiol Aging 2011; 32:991-1006. [DOI: 10.1016/j.neurobiolaging.2009.06.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 06/10/2009] [Accepted: 06/27/2009] [Indexed: 01/16/2023]
|
24
|
Contribution of neural networks to Alzheimer disease's progression. Brain Res Bull 2009; 80:309-14. [DOI: 10.1016/j.brainresbull.2009.06.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 06/05/2009] [Accepted: 06/06/2009] [Indexed: 11/21/2022]
|
25
|
Perez SE, Lumayag S, Kovacs B, Mufson EJ, Xu S. Beta-amyloid deposition and functional impairment in the retina of the APPswe/PS1DeltaE9 transgenic mouse model of Alzheimer's disease. Invest Ophthalmol Vis Sci 2008; 50:793-800. [PMID: 18791173 DOI: 10.1167/iovs.08-2384] [Citation(s) in RCA: 166] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To determine whether beta-amyloid (Abeta) deposition affects the structure and function of the retina of the APPswe/PS1DeltaE9 transgenic (tg) mouse model of Alzheimer's disease. METHODS Retinas from 12- to 19-month old APPswe/PS1DeltaE9 tg and age-matched non-transgenic (ntg) littermates were single or double stained with thioflavine-S and antibodies against Abeta, glial fibrillar acidic protein (GFAP), microglial marker F4/80, choline acetyltransferase (ChAT), and syntaxin 1. Quantification of thioflavine-S positive plaques and retinal layer thickness was analyzed semi-quantitatively, whereas microglial cell size and levels of F4/80 immunoreactivity were evaluated using a densitometry program. Scotopic electroretinogram (ERG) recording was used to investigate retinal physiology in these mice. RESULTS Thioflavine-S positive plaques appeared at 12 months in the retinas of APPswe/PS1DeltaE9 tg mice with the majority of plaques in the outer and inner plexiform layers. Plaques were embedded in the inner plexiform layer strata displaying syntaxin 1 and ChAT. The number and size of the plaques in the retina increased with age. Plaques appeared earlier and in greater numbers in females than in male tg littermate mice. Microglial activity was significantly increased in the retinas of APPswe/PS1DeltaE9 tg mice. Although we did not detect neuronal degeneration in the retina, ERG recordings revealed a significant reduction in the amplitudes of a- and b-waves in aged APPswe/PS1DeltaE9 tg compared to ntg littermates. CONCLUSIONS The present findings suggest that Abeta deposition disrupts retinal structure and may contribute to the visual deficits seen in aged APPswe/PS1DeltaE9 tg mice. Whether Abeta is involved in other forms of age-related retinal dysfunction is unclear.
Collapse
Affiliation(s)
- Sylvia E Perez
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | | | | | | | | |
Collapse
|
26
|
Neveu MM, von dem Hagen E, Morland AB, Jeffery G. The fovea regulates symmetrical development of the visual cortex. J Comp Neurol 2008; 506:791-800. [PMID: 18076059 DOI: 10.1002/cne.21574] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The foveal region contains the highest cell density in the human retina; consequently a disproportionately large area of the visual cortex is dedicated to its representation. In aniridia and albinism the fovea does not develop, and the corresponding cortical representation shows a reduction in gray matter volume. In albinos there are chiasmatic irregularities in the hemispheric projections, which are not found in aniridics. Here, we ask whether the anomalies in central retinal development, present in albinism and aniridia, have a wider impact on the architecture of the visual cortex. The length, depth, and topology of the calcarine fissure is analyzed in albino, aniridic, and normal subjects. These measures are compared between groups and between the cortical hemispheres within each subject. We show that the calcarine fissure, where the primary visual cortex is represented, is abnormally short in those lacking a fovea. Moreover, surface reconstructions of the calcarine fissure revealed marked interhemispheric asymmetries. The two groups could not be distinguished on the basis of their cortical features, and we therefore interpret the abnormalities in cortical architecture in terms of the absence of the fovea, the common retinal feature found in both groups.
Collapse
Affiliation(s)
- Magella M Neveu
- Institute of Ophthalmology, University College London, London, United Kingdom
| | | | | | | |
Collapse
|
27
|
Klevay LM. Alzheimer’s disease as copper deficiency. Med Hypotheses 2008; 70:802-7. [DOI: 10.1016/j.mehy.2007.04.051] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Accepted: 04/16/2007] [Indexed: 12/31/2022]
|
28
|
Dorph-Petersen KA, Pierri JN, Wu Q, Sampson AR, Lewis DA. Primary visual cortex volume and total neuron number are reduced in schizophrenia. J Comp Neurol 2007; 501:290-301. [PMID: 17226750 DOI: 10.1002/cne.21243] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A number of studies that assessed the visual system in subjects with schizophrenia found impairments in early visual processing. Furthermore, functional imaging studies suggested changes in primary visual cortex activity in subjects with schizophrenia. Interestingly, postmortem studies of subjects with schizophrenia reported an increased density of neurons in the primary visual cortex (Brodmann's area 17, BA17). The observed changes in visual processing may thus be reflected in structural changes in the circuitry of BA17. To characterize the structural changes further we used stereological methods based on unbiased principles of sampling (Cavalieri's principle and the optical fractionator) to estimate the total volume and neuron number of BA17 in postmortem brains from 10 subjects with schizophrenia and 10 matched normal comparison subjects. In addition, we assessed cortical thickness. We found a marked and significant reduction in total neuron number (25%) and volume (22%) of BA17 in the schizophrenia group relative to the normal comparison subjects. In contrast, we found no changes in neuronal density or cortical thickness between the two groups. Subjects with schizophrenia therefore have a smaller cortical area allocated to primary visual perception. This finding suggests the existence of a schizophrenia-related change in cortical parcellation.
Collapse
|
29
|
Voelcker-Rehage C, Godde B, Staudinger UM. [Activity, physical and psychological mobility in old age]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2006; 49:558-66. [PMID: 16673070 DOI: 10.1007/s00103-006-1269-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Old age and aging are accompanied by a number of physical and mental changes. However, these so-called age-dependent processes are not exclusively genetically determined or irreversible but can be partially delayed, prevented, or compensated and some can even be reversed. The goal of this article is to highlight the plasticity, or the "mobility", of physical and mental aging. We will point out in what respects an appropriate lifestyle or purposeful interventions can positively influence the reserve capacity of aging human beings and the aging process. Using the example of physical activity, we will illustrate how we can influence physiological development, cognitive performance, longevity, as well as the development and the occurrence of chronic diseases. Additionally, it is shown that cognitive development is malleable as well. It is facilitated or debilitated by behavior and activity-this covers not only cognitive but also physical activity. It is our particular concern to demonstrate the close interconnectedness of body and mind.
Collapse
Affiliation(s)
- C Voelcker-Rehage
- Jacobs Center for Lifelong Learning and Institutional Development, International University Bremen, Campus Ring 1, 28759 Bremen.
| | | | | |
Collapse
|
30
|
Götz J, Ittner LM, Kins S. Do axonal defects in tau and amyloid precursor protein transgenic animals model axonopathy in Alzheimer's disease? J Neurochem 2006; 98:993-1006. [PMID: 16787410 DOI: 10.1111/j.1471-4159.2006.03955.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The subcellular localization of organelles, mRNAs and proteins is particularly challenging in neurons. Owing to their extended morphology, with axons in humans exceeding a meter in length, in addition to which they are not renewed but persist for the entire lifespan, it is no surprise that neurons are highly vulnerable to any perturbation of their sophisticated transport machinery. There is emerging evidence that impaired transport is not only causative for a range of motor disorders, but possibly also for Alzheimer's disease (AD) and related neurodegenerative disorders. Support for this hypothesis comes from transgenic animal models. Overexpression of human tau and amyloid precursor protein (APP) in mice and flies models the key hallmark histopathological characteristics of AD, such as somatodendritic accumulation of phosphorylated forms of tau and beta-amyloid (Abeta) peptide-containing amyloid plaques, as well as axonopathy. The latter has also been demonstrated in mutant mice with altered levels of Alzheimer-associated genes, such as presenilin (PS). In Abeta-producing APP transgenic mice, axonopathy was observed before the onset of plaque formation and tau hyperphosphorylation. In human AD brain, an axonopathy was revealed for early but not late Braak stages. The overall picture is that key players in AD, such as tau, APP and PS, perturb axonal transport early on in AD, causing impaired synaptic plasticity and reducing survival rates. It will be challenging to determine the molecular mechanisms of these different axonopathies, as this might assist in the development of new therapeutic strategies.
Collapse
Affiliation(s)
- Jürgen Götz
- Brain and Mind Research Institute, University of Sydney, Camperdown, New South Wales, Australia.
| | | | | |
Collapse
|
31
|
Tales A, Butler S. Visual mismatch negativity highlights abnormal preattentive visual processing in Alzheimer's disease. Neuroreport 2006; 17:887-90. [PMID: 16738482 DOI: 10.1097/01.wnr.0000223383.42295.fa] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mismatch negativity has been found to decline in amplitude with increasing age and also in Alzheimer's disease. It has been suggested that the reduction in amplitude of mismatch negativity in Alzheimer's disease is the result of fatigue rather than a generalized decline in neuronal response. We tested this hypothesis by measuring the effect of time on task on the visual mismatch negativity in both normal aging and in Alzheimer's disease. In older adults, visual mismatch negativity showed a reduction in amplitude, which did not vary with time on task. This argues against fatigue as the cause of visual mismatch negativity amplitude reduction in normal ageing. In Alzheimer's disease, visual mismatch negativity was virtually absent in responses to the first 16 deviant stimuli but present in response to subsequent deviants. This is opposite to the effect predicted by the fatigue hypothesis. It suggests that individuals with Alzheimer's disease are initially refractory to stimulus change.
Collapse
Affiliation(s)
- Andrea Tales
- Department of Care of the Elderly, The BRACE Centre, University of Bristol, Blackberry Hill Hospital, Bristol, UK
| | | |
Collapse
|
32
|
von Gunten A, Bouras C, Kövari E, Giannakopoulos P, Hof PR. Neural substrates of cognitive and behavioral deficits in atypical Alzheimer's disease. ACTA ACUST UNITED AC 2006; 51:176-211. [PMID: 16413610 DOI: 10.1016/j.brainresrev.2005.11.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 11/04/2005] [Accepted: 11/11/2005] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a progressive cognitive decline that typically affects first memory and later executive functions, language, and visuospatial skills. This sequence of cognitive deterioration is thought to reflect the progressive invasion of the cerebral cortex by the two major pathological hallmarks of AD, neurofibrillary tangles (NFT) and senile plaques (SP), as well as degree of neuronal and synaptic loss. In atypical AD, prominent and early deficits are found in language, motor abilities, frontal and executive capacities, or visuospatial skills. These atypical clinical features are associated with an unusual pattern of NFT or SP formation that predominantly involves cortical areas usually spared in the course of the degenerative process. In an attempt to classify this highly heterogeneous subgroup, the present article provides an overview of clinicopathological analyses in patients with atypical progression of AD symptomatology with special reference to the relationship between specific cognitive and behavioral deficits and hierarchical patterns of AD lesion distribution within the cerebral cortex. On the basis of these representative examples of a cortical circuit-based approach to explore the mechanisms giving rise to AD neuropsychological expression, we also critically discuss the possibility to develop a matrix linking clinical presentations to degeneration of forward and backward long corticocortical pathways in this disorder.
Collapse
Affiliation(s)
- Armin von Gunten
- Division of Old Age Psychiatry, Department of Psychiatry-CHUV, Prilly-Lausanne, Switzerland.
| | | | | | | | | |
Collapse
|
33
|
Tales A, Muir J, Jones R, Bayer A, Snowden RJ. The effects of saliency and task difficulty on visual search performance in ageing and Alzheimer's disease. Neuropsychologia 2004; 42:335-45. [PMID: 14670572 DOI: 10.1016/j.neuropsychologia.2003.08.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We asked whether the poor performance on visual search tasks typical of patients with Alzheimer's disease (AD) is the result of a selective deficit in the ability to shift attention from item to item, or the consequence of an inefficient processing of each item within the search set. We attempted to manipulate the ease of attention shifting and item processing in a visual search task by manipulating target salience and task difficulty, respectively. Significant effects of both target saliency and task difficulty for both AD patients and age-matched controls were obtained, with the AD group displaying greater effects of both of these manipulations than the controls. This interaction remained even when the reaction time data were log-transformed to account for the overall slower reaction times of the AD group. We conclude that inefficiency in visual search tasks in AD probably represents the product of both attention shifting and target processing factors.
Collapse
Affiliation(s)
- Andrea Tales
- School of Psychology, Cardiff University, Cardiff CF11 3YG, Wales, UK
| | | | | | | | | |
Collapse
|
34
|
del Valle E, Navarro A, Astudillo A, Tolivia J. Apolipoprotein D expression in human brain reactive astrocytes. J Histochem Cytochem 2003; 51:1285-90. [PMID: 14500696 DOI: 10.1177/002215540305101005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Astrocytosis is a hallmark of damage that frequently occurs during aging in human brain. Astrocytes proliferate in elderly subjects, becoming hypertrophic and highly immunoreactive for glial fibrillary acidic protein (GFAP). These cells are one type that actively responds in the repair and reorganization of damage to the neural parenchyma and are a source of several peptides and growth factors. One of these biomolecules is apolipoprotein D (apo D), a member of the lipocalin family implicated in the transport of small hydrophobic molecules. Although the role of apo D is unknown, increments in brain apo D expression have been observed in association with aging and with some types of neuropathology. We have found an overexpression of apo D mRNA in reactive astrocytes by in situ hybridization in combination with immunohistochemistry for apo D in normal aged human brains. The number of double-labeled cells varied according to the cerebral area and the gliosis grade. The possible significance of this increased synthesis of apo D in reactive astrocytes is discussed in relation to the role of apo D in aging and in glial function.
Collapse
Affiliation(s)
- Eva del Valle
- Departamento de Morfología y Biología Celular, Facultad de Biología y Medicina, Universidad de Oviedo, España
| | | | | | | |
Collapse
|
35
|
Díaz F, Moreno P, Villena A, Vidal L, Pérez De Vargas I. Effects of aging on neurons and glial cells from the superficial layers of the superior colliculus in rats. Microsc Res Tech 2003; 62:431-8. [PMID: 14601149 DOI: 10.1002/jemt.10404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this study was to investigate the effect of aging on glial cells and neurons from the superficial layers of the superior colliculus in rats. We used stereological methods to estimate the volume of the superficial layers, neuron size, and the number of neurons and glial cells in Wistar male rats aged 3, 24, 26, and 28 months. A 32.6% volume increase was found in the stratum griseum superficiale between the ages of 3 and 26 months, while in the 28-month-old animals a 19% decrease was observed. The stratum opticum did not show any changes in volume with age. Also, our analysis revealed a process of somatic and nuclear atrophy in the neurons of the superficial layers in animals aged 26 and 28 months. On the other hand, no statistically significant differences were found in the numbers of neurons. The number of glial cells in the stratum griseum superficiale showed an increase between the 3rd and 26th month, while the stratum opticum suffered no change.
Collapse
Affiliation(s)
- Florentina Díaz
- Department of Histology and Pathology, School of Medicine, University of Málaga, 29071 Málaga, Spain.
| | | | | | | | | |
Collapse
|
36
|
Newberg A, Cotter A, Udeshi M, Brinkman F, Glosser G, Alavi A, Clark C. Brain metabolism in the cerebellum and visual cortex correlates with neuropsychological testing in patients with Alzheimer's disease. Nucl Med Commun 2003; 24:785-90. [PMID: 12813197 DOI: 10.1097/01.mnm.0000080249.50447.99] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This study was designed to measure glucose metabolic deficits in areas not typically recognized as abnormal on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans in patients with Alzheimer's disease (AD), and to correlate such findings with subtle neuropsychological impairment. FDG-PET scans on 38 AD patients with no clinical evidence of visual, spatial or motor deficits were acquired on the PET HEAD scanner 40 min following the intravenous administration of 115 microCi.kg-1 of FDG. All FDG-PET scans were analysed blindly using a region of interest (ROI) template with regions for the primary visual cortex (PVC), secondary visual cortex (SVC) and cerebellum. Counts from the ROIs of these regions were normalized to whole brain activity and the results were compared with psychometric and neuropsychological measures. A number of significant correlations were found between these structures and various neuropsychological measures (P<0.05). Specifically, there were significant correlations between clock drawing and the cerebellum activity; memory and activity in the PVC, SVC and cerebellum; social score and activity in the PVC and left cerebellum; judgement and activity in the right SVC and right PVC; and the overall Mini-Mental State Examination and activity in the PVC, SVC and cerebellum. The results of this study suggest that metabolism in areas not typically recognized as abnormal on FDG-PET scans in AD, such as the PVC, SVC and cerebellum, is correlated with deficits in neuropsychological function. This may have important clinical and pathophysiological implications in the study of AD and other illnesses of dementia.
Collapse
Affiliation(s)
- A Newberg
- Department of Radiology and Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA.
| | | | | | | | | | | | | |
Collapse
|
37
|
|
38
|
Andrés N, Malpesa Y, Rodríguez MJ, Mahy N. Low sensitivity of retina to AMPA-induced calcification. J Neurosci Res 2003; 72:543-8. [PMID: 12704816 DOI: 10.1002/jnr.10601] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Glutamate is involved in most CNS neurodegenerative diseases. In particular, retinal diseases such as retinal ischemia, retinitis pigmentosa, and diabetic retinopathy are associated with an excessive synaptic concentration of this neurotransmitter. To gain more insight into retinal excitotoxicity, we carried out a dose-response study in adult rats using alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), a glutamate analogue. AMPA intraocular injections (between 0.27 and 10.8 nmol) caused no morphologic modification, but a 10.8 + 21 nmol double injection in a 10-day interval produced a lesion characterized by discrete neuronal loss, astroglial and microglial reactions, and calcium precipitation. Abundant calcium deposits similar to those present in rat and human brain excitotoxicity or hypoxia-ischemia neurodegeneration were detected by alizarin red staining within the retinal surface and the optic nerve. Glial reactivity, associated normally with astrocytes in the nerve fiber, was assessed in Müller cells. GABA immunoreactivity was detected not only in neuronal elements but also in Müller cells. In contrast to the high vulnerability of the brain to excitotoxin microinjection, AMPA-induced retinal neurodegeneration may provide a useful model of low central nervous system sensitivity to excitotoxicity.
Collapse
Affiliation(s)
- Noemí Andrés
- Unitat de Bioquímica, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
| | | | | | | |
Collapse
|
39
|
Vickers JC, Tan A, Dickson TC. Direct determination of the proportion of intra- and extra-cellular neocortical neurofibrillary tangles in Alzheimer's disease. Brain Res 2003; 971:135-7. [PMID: 12691846 DOI: 10.1016/s0006-8993(03)02429-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We investigated the cellular localisation of neurofibrillary tangles in Alzheimer's disease. All tau-positive tangles were stained for thioflavine S, while approximately 84% of thioflavine S-stained tangles were tau-immunolabelled. Approximately 58-62% and 73-76% of thioflavine S- and tau-labelled tangles, respectively, were present within cortical neurons labelled for microtubule-associated protein-2. Thus, most neocortical tangles in Alzheimer's disease are intracellular and may not be the principal cause of neocortical cell loss.
Collapse
Affiliation(s)
- James C Vickers
- Discipline of Pathology, School of Medicine, University of Tasmania, 43 Collins St, GPO Box 252-29, Tasmania Hobart 7001, Australia.
| | | | | |
Collapse
|
40
|
Tales A, Butler SR, Fossey J, Gilchrist ID, Jones RW, Troscianko T. Visual search in Alzheimer's disease: a deficiency in processing conjunctions of features. Neuropsychologia 2002; 40:1849-57. [PMID: 12207983 DOI: 10.1016/s0028-3932(02)00073-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Human vision often needs to encode multiple characteristics of many elements of the visual field, for example their lightness and orientation. The paradigm of visual search allows a quantitative assessment of the function of the underlying mechanisms. It measures the ability to detect a target element among a set of distractor elements. We asked whether Alzheimer's disease (AD) patients are particularly affected in one type of search, where the target is defined by a conjunction of features (orientation and lightness) and where performance depends on some shifting of attention. Two non-conjunction control conditions were employed. The first was a pre-attentive, single-feature, "pop-out" task, detecting a vertical target among horizontal distractors. The second was a single-feature, partly attentive task in which the target element was slightly larger than the distractors-a "size" task. This was chosen to have a similar level of attentional load as the conjunction task (for the control group), but lacked the conjunction of two features. In an experiment, 15 AD patients were compared to age-matched controls. The results suggested that AD patients have a particular impairment in the conjunction task but not in the single-feature size or pre-attentive tasks. This may imply that AD particularly affects those mechanisms which compare across more than one feature type, and spares the other systems and is not therefore simply an 'attention-related' impairment. Additionally, these findings show a double dissociation with previous data on visual search in Parkinson's disease (PD), suggesting a different effect of these diseases on the visual pathway.
Collapse
Affiliation(s)
- A Tales
- Burden Neurological Institute, Frenchay Hospital, Bristol BS16 1 JB, UK
| | | | | | | | | | | |
Collapse
|
41
|
Abstract
Human and non-human primates show cognitive decline during normal aging. Originally, the decline was attributed to a loss of cortical neurons, but recent studies have shown there is no significant cortical neuronal loss with age. Neurons acquire pigment, but the only other obvious changes are in layer 1 of neocortex. Layer 1 becomes thinner as apical tufts of pyramidal cells lose branches, as well as synapses, and at the same time the glial limiting membrane thickens. How dendrites and synapses in deep layers are affected by age is uncertain, but there are decreases in the levels of some neurotransmitters and receptors. Throughout the brain myelin sheaths show signs of breakdown. This may contribute to cognitive decline because it would cause a slowing of conduction along nerve fibers, disrupting the timing in neuronal circuits. Concomitantly, the myelin-forming oligodendrocytes develop swellings along their processes and gain dense inclusions. Microglial cells and astrocytes accumulate large amounts of phagocytosed material with age, although the origins of this material are not known.
Collapse
Affiliation(s)
- Alan Peters
- Department of Anatomy and Neurobiology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118-2526, USA.
| |
Collapse
|
42
|
Peters A. Structural changes in the normally aging cerebral cortex of primates. PROGRESS IN BRAIN RESEARCH 2002; 136:455-65. [PMID: 12143402 DOI: 10.1016/s0079-6123(02)36038-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
During normal aging humans exhibit some cognitive decline, but it is difficult to determine the underlying causes of this decline, because information about cognitive status is rarely available and preservation of the brain is usually inadequate for detailed cytological examination. One solution to this problem is to use a nonhuman primate model, such as the rhesus monkey, which exhibits age-related cognitive decline similar to humans, and can be cognitively tested before the brains are preserved for detailed examination. It is now known that cognitive decline in human and nonhuman primates is not due to loss of cortical neurons and there is no correlation between the frequency of senile plaques and cognitive status. Indeed apart from layer 1, neurons of cerebral cortex show few signs of aging, although there may be some loss of synapses throughout cortex. In contrast, both microglia and astrocytes come to contain phagocytosed material, but its origin is unknown. There is also loss of white matter, which is accompanied by some breakdown of myelin sheaths and alterations in oligodendrocytes. It is suggested that the myelin changes alter conduction velocities along axons. This would alter timing in neuronal circuits, contributing to cognitive decline.
Collapse
Affiliation(s)
- Alan Peters
- Department of Anatomy and Neurobiology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118-2526, USA.
| |
Collapse
|
43
|
Turlejski K, Djavadian R. Life-long stability of neurons: a century of research on neurogenesis, neuronal death and neuron quantification in adult CNS. PROGRESS IN BRAIN RESEARCH 2002; 136:39-65. [PMID: 12143397 DOI: 10.1016/s0079-6123(02)36006-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this chapter we provide an extensive review of 100 years of research on the stability of neurons in the mammalian brain, with special emphasis on humans. Although Cajal formulated the Neuronal Doctrine, he was wrong in his beliefs that adult neurogenesis did not occur and adult neurons are dying throughout life. These two beliefs became accepted "common knowledge" and have shaped much of neuroscience research and provided much of the basis for clinical treatment of age-related brain diseases. In this review, we consider adult neurogenesis from a historical and evolutionary perspective. It is concluded, that while adult neurogenesis is a factor in the dynamics of the dentate gyrus and olfactory bulb, it is probably not a major factor during the life-span in most brain areas. Likewise, the acceptance of neuronal death as an explanation for normal age-related senility is challenged with evidence collected over the last fifty years. Much of the problem in changing this common belief of dying neurons was the inadequacies of neuronal counting methods. In this review we discuss in detail implications of recent improvements in neuronal quantification. We conclude: First, age-related neuronal atrophy is the major factor in functional deterioration of existing neurons and could be slowed down, or even reversed by various pharmacological interventions. Second, in most cases neuronal degeneration during aging is a pathology that in principle may be avoided. Third, loss of myelin and of the white matter is more frequent and important than the limited neuronal death in normal aging.
Collapse
Affiliation(s)
- Kris Turlejski
- Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland.
| | | |
Collapse
|
44
|
Kril JJ, Halliday GM. Alzheimer's disease: its diagnosis and pathogenesis. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2002; 48:167-217. [PMID: 11526738 DOI: 10.1016/s0074-7742(01)48016-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A hypothesis has been presented that links many of the identified and putative risk factors for AD and suggests a mechanism for their action. Crawford (1996, 1998) proposes an association between AD and cerebral blood flow (CBF) by citing evidence that many of the factors that are linked with an increased risk of AD also decrease CBF (e.g., old age, depression, underactivity, head trauma). Similarly, it is suggested factors that increase CBF are associated with a decreased risk of AD (e.g., education, exercise, smoking, NSAIDs). Although the authors acknowledge that reduced CBF is not sufficient to cause AD, the reported positive and negative associations provide tantalizing evidence for a common mode of action for many of the equivocal risk factors reported to date. This hypothesis is also consistent with other data that links microvascular damage and impaired blood flow (de la Torre, 1997, 2000) and low education with increased cerebrovascular disease (Del Ser et al., 1999). Gaining a better understanding of the interaction between AD and vascular disease is of great importance. Not only will it provide insights into the pathogenesis of AD, but it may also provide us with a rare opportunity for the treatment and possible prevention of AD. A great many risk factors for vascular disease have been identified and intervention programs have successfully reduced the incidence of heart disease and stroke. The potential exists to provide the same level of success with AD.
Collapse
Affiliation(s)
- J J Kril
- Centre for Education and Research on Ageing, Concord Hospital, Department of Medicine, University of Sydney, Concord, New South Wales, Australia 2130
| | | |
Collapse
|
45
|
Hara J, Shankle WR, Musha T. Cortical atrophy in Alzheimer's disease unmasks electrically silent sulci and lowers EEG dipolarity. IEEE Trans Biomed Eng 1999; 46:905-10. [PMID: 10431454 DOI: 10.1109/10.775399] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alzheimer's disease (AD) patients show lower dipolarity (goodness-of-fit) for dipole localizations of alpha or other dominant electroencephalography (EEG) frequency components in the occipital cortex. In the present study, we performed computer simulations to discover which of distributions of dipole activity lower dipolarity in a manner similar to that seen in severe AD. Dipolarity was estimated from simulations of various electric dipole generator configurations within the occipital cortex under conditions of widened cortical sulci (a severely demented AD case) or no sulcal widening (a normal subject). The cortical and scalp surfaces, derived from the subjects' MRI's, were assumed to be uniformly electrically conducting. Randomly placed, nonoverlapping lesions ranging from 1 to 4 mm2 per lesion were used in both the normal and AD models to simulate the electrical effect of neuropathological AD lesions. In both models, dipolarity decreased as total lesion size increased. However, the AD model showed lower dipolarity than the normal model for both individual lesion sizes and for larger total lesion sizes. The larger decline in dipolarity in the AD model appears to be due to sulcal widening which unmasks the effect of lesions buried within sulci. These simulations identify a possible mechanism explaining why sulcally-located neuropathological changes plus progressive cortical atrophy in AD brains (and presumably other cortical disorders producing atrophy) alter EEG patterns and dipolarity differently from normal cortex damaged by similar lesions.
Collapse
Affiliation(s)
- J Hara
- Bioinformatics Laboratory, Keio University, Kanagawa, Japan.
| | | | | |
Collapse
|
46
|
Diaz F, Villena A, Gonzalez P, Requena V, Rius F, Perez De Vargas I. Stereological age-related changes in neurons of the rat dorsal lateral geniculate nucleus. THE ANATOMICAL RECORD 1999; 255:396-400. [PMID: 10409812 DOI: 10.1002/(sici)1097-0185(19990801)255:4<396::aid-ar5>3.0.co;2-m] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Quantitative methods were used to compare the changes taking place in the volume of the dorsal lateral geniculate nucleus (dLGN) and corresponding neurons of young, adult and old rats. The study was carried out on male albino rats aged 3, 18, 24 and 28 months. In order to estimate the volume of the dLGN, neuronal volume density, numerical density and total number of neurons, we used serial sections stained according to the Klüver-Barrera technique and stereological methods. We found that dorsal lateral geniculate nucleus volume increases between 3 and 28 months, with a larger increase between 24 and 28 months. Neuronal volume density and numerical density of neurons are greater at 3 months and undergo a significant decrease between 24 and 28 months. Finally, the total number of neurons is shown to be smaller in adult and old animals than in younger ones, even though no significant variations are found between 18 and 28 months. Furthermore, this study confirms the need to analyze the total number of neurons and not just neuronal density if we want to correctly evaluate some of the microscopic changes occurring during senescence.
Collapse
Affiliation(s)
- F Diaz
- Department of Normal and Pathological Morphology, Faculty of Medicine, University of Málaga, 29080 Málaga, Spain.
| | | | | | | | | | | |
Collapse
|
47
|
Kish SJ, Mastrogiacomo F, Guttman M, Furukawa Y, Taanman JW, Dozić S, Pandolfo M, Lamarche J, DiStefano L, Chang LJ. Decreased brain protein levels of cytochrome oxidase subunits in Alzheimer's disease and in hereditary spinocerebellar ataxia disorders: a nonspecific change? J Neurochem 1999; 72:700-7. [PMID: 9930743 DOI: 10.1046/j.1471-4159.1999.0720700.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Controversy exists as to the clinical importance, cause, and disease specificity of the cytochrome oxidase (CO) activity reduction observed in some patients with Alzheimer's disease (AD). Although it is assumed that the enzyme is present in normal amount in AD, no direct measurements of specific CO protein subunits have been conducted. We measured protein levels of CO subunits encoded by mitochondrial (COX I, COX II) and nuclear (COX IV, COX VIc) DNA in autopsied brain of patients with AD whom we previously reported had decreased cerebral cortical CO activity. To assess disease specificity, groups of patients with spinocerebellar ataxia type I and Friedreich's ataxia were also included. As compared with the controls, mean protein concentrations of all four CO subunits were significantly decreased (-19 to -47%) in temporal and parietal cortices in the AD group but were not significantly reduced (-12 to -17%) in occipital cortex. The magnitude of the reduction in protein levels of the CO subunits encoded by mitochondrial DNA (-42 to -47%) generally exceeded that encoded by nuclear DNA (-19 to -43%). In the spinocerebellar ataxia disorders, COX I and COX II levels were significantly decreased in cerebellar cortex (-22 to -32%) but were normal or close to normal in cerebral cortex, an area relatively unaffected by neurodegeneration. We conclude that protein levels of mitochondrial- and nuclear-encoded CO subunits are moderately reduced in degenerating but not in relatively spared brain areas in AD and that the decrease is not specific to this disorder. The simplest explanation for our findings is that CO is decreased in human brain disorders as a secondary event in brain areas having reduced neuronal activity or neuronal/synaptic elements consequent to the primary neurodegenerative process.
Collapse
Affiliation(s)
- S J Kish
- Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
|
49
|
Leuba G, Kraftsik R, Saini K. Quantitative distribution of parvalbumin, calretinin, and calbindin D-28k immunoreactive neurons in the visual cortex of normal and Alzheimer cases. Exp Neurol 1998; 152:278-91. [PMID: 9710527 DOI: 10.1006/exnr.1998.6838] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The distribution of parvalbumin (PV), calretinin (CR), and calbindin (CB) immunoreactive neurons was studied with the help of an image analysis system (Vidas/Zeiss) in the primary visual area 17 and associative area 18 (Brodmann) of Alzheimer and control brains. In neither of these areas was there a significant difference between Alzheimer and control groups in the mean number of PV, CR, or CB immunoreactive neuronal profiles, counted in a cortical column going from pia to white matter. Significant differences in the mean densities (numbers per square millimeter of cortex) of PV, CR, and CB immunoreactive neuronal profiles were not observed either between groups or areas, but only between superficial, middle, and deep layers within areas 17 and 18. The optical density of the immunoreactive neuropil was also similar in Alzheimer and controls, correlating with the numerical density of immunoreactive profiles in superficial, middle, and deep layers. The frequency distribution of neuronal areas indicated significant differences between PV, CR, and CB immunoreactive neuronal profiles in both areas 17 and 18, with more large PV than CR and CB positive profiles. There were also significantly more small and less large PV and CR immunoreactive neuronal profiles in Alzheimer than in controls. Our data show that, although the brain pathology is moderate to severe, there is no prominent decrease of PV, CR and CB positive neurons in the visual cortex of Alzheimer brains, but only selective changes in neuronal perikarya.
Collapse
Affiliation(s)
- G Leuba
- University Psychogeriatrics Hospital, Lausanne, CH-1008, Switzerland
| | | | | |
Collapse
|
50
|
Yoshida H, Watanabe A, Ihara Y. Collapsin response mediator protein-2 is associated with neurofibrillary tangles in Alzheimer's disease. J Biol Chem 1998; 273:9761-8. [PMID: 9545313 DOI: 10.1074/jbc.273.16.9761] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intraneuronal accumulation of paired helical filaments (PHF) is considered to be closely related to the neuronal loss observed in brains of patients affected with Alzheimer's disease. The central issue is whether PHF formation itself causes or accelerates the neuronal perikaryal and neuritic degeneration or whether they are simply the consequence of preceding degeneration. We sought to address the issue in part by characterizing the PHF-associated molecules and thus raised a number of monoclonal antibodies to neurofibrillary tangles. One monoclonal antibody, 3F4, strongly reacted with neurofibrillary tangles and some plaque neurites but few neuropil threads. This monoclonal antibody labeled a 65-kDa protein, but not tau or ubiquitin, on a Western blot of human brain extract and immunoprecipitated the same protein. The peptides released from the purified 65-kDa protein had the same sequences as those of a newly identified protein, human collapsin response mediator protein-2. Incorporation into neurofibrillary tangles may deplete soluble, cytosolic human collapsin response mediator protein-2 and lead to abnormal neuritic and/or axonal outgrowth of the tangle-bearing neuron, thus accelerating the neuritic degeneration in Alzheimer's disease.
Collapse
Affiliation(s)
- H Yoshida
- Department of Neuropathology, Faculty of Medicine, University of Tokyo 113-0033, Tokyo, Japan
| | | | | |
Collapse
|