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Barrett MJ, Murphy JM, Zhang J, Blair JC, Flanigan JL, Nawaz H, Dalrymple WA, Sperling SA, Patrie J, Druzgal TJ. Olfaction, cholinergic basal forebrain degeneration, and cognition in early Parkinson disease. Parkinsonism Relat Disord 2021; 90:27-32. [PMID: 34348192 DOI: 10.1016/j.parkreldis.2021.07.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Impaired olfaction and reduced cholinergic nucleus 4 (Ch4) volume both predict greater cognitive decline in Parkinson's disease (PD). We examined the relationship between olfaction, longitudinal change in cholinergic basal forebrain nuclei and their target regions, and cognition in early PD. METHODS We analyzed a cohort of 97 PD participants from the Parkinson's Progression Markers Initiative with brain MRIs at baseline, 1 year, 2 years, and 4 years. Using probabilistic maps, regional grey matter density (GMD) was calculated for Ch4, cholinergic nuclei 1, 2, and 3 (Ch123), and their target regions. RESULTS Baseline University of Pennsylvania Smell Identification Test score correlated with change in GMD of all regions of interest (all p < 0.05). Rate of change of Ch4 GMD was correlated with rate of change of Ch123 (p = 0.034), cortex (p = 0.001), and amygdala GMD (p < 0.001), but not hippocampus GMD (p = 0.38). Rate of change of Ch123 GMD was correlated with rate of change of cortex (p = 0.001) and hippocampus (p < 0.001), but not amygdala GMD (p = 0.133). In a linear regression model including change in GMD of all regions of interest and age as predictors, change in cortex GMD (βˆslope= 38.2; 95 % CI: [0.47, 75.9]) and change in hippocampus GMD (βˆslope= 24.8; 95 % CI: [0.80, 48.8]) were significant predictors of Montreal Cognitive Assessment score change over time. CONCLUSION Impaired olfaction is associated with degeneration of the cholinergic basal forebrain and bilateral cortex, amygdala, and hippocampus in PD. The relationship between impaired olfaction and cognitive decline may be mediated by greater atrophy of the cortex and hippocampus.
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Affiliation(s)
- Matthew J Barrett
- Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA.
| | - Justin M Murphy
- School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Jeffrey Zhang
- School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Jamie C Blair
- Department of Radiology and Medical Imaging, Division of Neuroradiology, University of Virginia Health System, Charlottesville, VA, USA
| | - Joseph L Flanigan
- Department of Neurology, University of Virginia, Charlottesville, VA, USA
| | - Huma Nawaz
- Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA
| | - W Alex Dalrymple
- Department of Neurology, University of Virginia, Charlottesville, VA, USA
| | - Scott A Sperling
- Department of Neurology, University of Virginia, Charlottesville, VA, USA
| | - James Patrie
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA
| | - T Jason Druzgal
- Department of Radiology and Medical Imaging, Division of Neuroradiology, University of Virginia Health System, Charlottesville, VA, USA
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Falangola MF, Nie X, Ward R, Dhiman S, Voltin J, Nietert PJ, Jensen JH. Diffusion MRI detects basal forebrain cholinergic abnormalities in the 3xTg-AD mouse model of Alzheimer's disease. Magn Reson Imaging 2021; 83:1-13. [PMID: 34229088 DOI: 10.1016/j.mri.2021.06.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/24/2021] [Accepted: 06/29/2021] [Indexed: 12/17/2022]
Abstract
Degeneration of the basal forebrain (BF) is detected early in the course of Alzheimer's disease (AD). Reduction in the number of BF cholinergic (ChAT) neurons associated with age-related hippocampal cholinergic neuritic dystrophy is described in the 3xTg-AD mouse model; however, no prior diffusion MRI (dMRI) study has explored the presence of BF alterations in this model. Here we investigated the ability of diffusion MRI (dMRI) to detect abnormalities in BF microstructure for the 3xTg-AD mouse model, along with related pathology in the hippocampus (HP) and white matter (WM) tracks comprising the septo-hippocampal pathway. 3xTg-AD and normal control (NC) mice were imaged in vivo using the specific dMRI technique known as diffusional kurtosis imaging (DKI) at 2, 8, and 15 months of age, and 8 dMRI parameters were measured at each time point. Our results revealed significant lower dMRI values in the BF of 2 months-old 3xTg-AD mice compared with NC mice, most likely related to the increased number of ChAT neurons seen in this AD mouse model at this age. They also showed significant age-related dMRI changes in the BF of both groups between 2 and 8 months of age, mainly a decrease in fractional anisotropy and axial diffusivity, and an increase in radial kurtosis. These dMRI changes in the BF may be reflecting the complex aging and pathological microstructural changes described in this region. Group differences and age-related changes were also observed in the HP, fimbria (Fi) and fornix (Fx). In the HP, diffusivity values were significantly higher in the 2 months-old 3xTg-AD mice, and the HP of NC mice showed a significant increase in axial kurtosis after 8 months, reflecting a normal pattern of increased fiber density complexity, which was not seen in the 3xTg-AD mice. In the Fi, mean and radial diffusivity values were significantly higher, and fractional anisotropy, radial kurtosis and kurtosis fractional anisotropy were significantly lower in the 2 months-old 3xTg-AD mice. The age trajectories for both NC and TG mice in the Fi and Fx were similar between 2 and 8 months, but after 8 months there was a significant decrease in diffusivity metrics associated with an increase in kurtosis metrics in the 3xTg-AD mice. These later HP, Fi and Fx dMRI changes probably reflect the growing number of dystrophic neurites and AD pathology progression in the HP, accompanied by WM disruption in the septo-hippocampal pathway. Our results demonstrate that dMRI can detect early cytoarchitectural abnormalities in the BF, as well as related aging and neurodegenerative changes in the HP, Fi and Fx of the 3xTg-AD mice. Since DKI is widely available on clinical scanners, these results also support the potential of the considered dMRI parameters as in vivo biomarkers for AD disease progression.
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Affiliation(s)
- Maria Fatima Falangola
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA.
| | - Xingju Nie
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Ralph Ward
- Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Siddhartha Dhiman
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Joshua Voltin
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Paul J Nietert
- Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Jens H Jensen
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA; Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
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Tiernan CT, Ginsberg SD, He B, Ward SM, Guillozet-Bongaarts AL, Kanaan NM, Mufson EJ, Counts SE. Pretangle pathology within cholinergic nucleus basalis neurons coincides with neurotrophic and neurotransmitter receptor gene dysregulation during the progression of Alzheimer's disease. Neurobiol Dis 2018; 117:125-136. [PMID: 29859871 PMCID: PMC6278831 DOI: 10.1016/j.nbd.2018.05.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 05/30/2018] [Indexed: 01/22/2023] Open
Abstract
Cholinergic basal forebrain neurons of the nucleus basalis of Meynert (nbM) regulate attentional and memory function and are exquisitely prone to tau pathology and neurofibrillary tangle (NFT) formation during the progression of Alzheimer's disease (AD). nbM neurons require the neurotrophin nerve growth factor (NGF), its cognate receptor TrkA, and the pan-neurotrophin receptor p75NTR for their maintenance and survival. Additionally, nbM neuronal activity and cholinergic tone are regulated by the expression of nicotinic (nAChR) and muscarinic (mAChR) acetylcholine receptors as well as receptors modulating glutamatergic and catecholaminergic afferent signaling. To date, the molecular and cellular relationships between the evolution of tau pathology and nbM neuronal survival remain unknown. To address this knowledge gap, we profiled cholinotrophic pathway genes within nbM neurons immunostained for pS422, a pretangle phosphorylation event preceding tau C-terminal truncation at D421, or dual-labeled for pS422 and TauC3, a later stage tau neo-epitope revealed by this same C-terminal truncation event, via single-population custom microarray analysis. nbM neurons were obtained from postmortem tissues from subjects who died with an antemortem clinical diagnosis of no cognitive impairment (NCI), mild cognitive impairment (MCI), or mild/moderate AD. Quantitative analysis revealed significant downregulation of mRNAs encoding TrkA as well as TrkB, TrkC, and the Trk-mediated downstream pro-survival kinase Akt in pS422+ compared to unlabeled, pS422-negative nbM neurons. In addition, pS422+ neurons displayed a downregulation of transcripts encoding NMDA receptor subunit 2B, metabotropic glutamate receptor 2, D2 dopamine receptor, and β1 adrenoceptor. By contrast, transcripts encoding p75NTR were downregulated in dual-labeled pS422+/TauC3+ neurons. Appearance of the TauC3 epitope was also associated with an upregulation of the α7 nAChR subunit and differential downregulation of the β2 nAChR subunit. Notably, we found that gene expression patterns for each cell phenotype did not differ with clinical diagnosis. However, linear regression revealed that global cognition and Braak stage were predictors of select transcript changes within both unlabeled and pS422+/TauC3- neurons. Taken together, these cell phenotype-specific gene expression profiling data suggest that dysregulation of neurotrophic and neurotransmitter signaling is an early pathogenic mechanism associated with NFT formation in vulnerable nbM neurons and cognitive decline in AD, which may be amenable to therapeutic intervention early in the disease process.
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Affiliation(s)
- Chelsea T Tiernan
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone School of Medicine, New York, NY, USA; Department of Physiology & Neuroscience, NYU Langone School of Medicine, New York, NY, USA; NYU Neuroscience Institute, NYU Langone School of Medicine, New York, NY, USA
| | - Bin He
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Sarah M Ward
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | | | - Nicholas M Kanaan
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Hauenstein Neurosciences Center, Mercy Health Saint Mary's Hospital, Grand Rapids, MI, USA
| | - Elliott J Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Scott E Counts
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Hauenstein Neurosciences Center, Mercy Health Saint Mary's Hospital, Grand Rapids, MI, USA; Department of Family Medicine, Michigan State University, Grand Rapids, MI, USA; Michigan Alzheimer's Disease Core Center, Ann Arbor, MI, USA.
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Teipel SJ, Cavedo E, Lista S, Habert MO, Potier MC, Grothe MJ, Epelbaum S, Sambati L, Gagliardi G, Toschi N, Greicius MD, Dubois B, Hampel H. Effect of Alzheimer's disease risk and protective factors on cognitive trajectories in subjective memory complainers: An INSIGHT-preAD study. Alzheimers Dement 2018; 14:1126-1136. [PMID: 29792873 DOI: 10.1016/j.jalz.2018.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/16/2018] [Accepted: 04/09/2018] [Indexed: 10/16/2022]
Abstract
INTRODUCTION Cognitive change in people at risk of Alzheimer's disease (AD) such as subjective memory complainers is highly variable across individuals. METHODS We used latent class growth modeling to identify distinct classes of nonlinear trajectories of cognitive change over 2 years follow-up from 265 subjective memory complainers individuals (age 70 years and older) of the INSIGHT-preAD cohort. We determined the effect of cortical amyloid load, hippocampus and basal forebrain volumes, and education on the cognitive trajectory classes. RESULTS Latent class growth modeling identified distinct nonlinear cognitive trajectories. Education was associated with higher performing trajectories, whereas global amyloid load and basal forebrain atrophy were associated with lower performing trajectories. DISCUSSION Distinct classes of cognitive trajectories were associated with risk and protective factors of AD. These associations support the notion that the identified cognitive trajectories reflect different risk for AD that may be useful for selecting high-risk individuals for intervention trials.
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Affiliation(s)
- Stefan J Teipel
- German Center for Neurodegenerative Diseases (DZNE)-Rostock/Greifswald, Rostock, Germany; Department of Psychosomatic Medicine, University of Rostock, Rostock, Germany.
| | - Enrica Cavedo
- AXA Research Fund & Sorbonne Université Chair, Paris, France; Sorbonne Université, GRC n° 21, Alzheimer Precision Medicine (APM), AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France; Institut du Cerveau et de la Moelle Épiniére (ICM), INSERM U 1127, CNRS UMR 7225, Paris, France; Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France; IRCCS Centro San Giovanni di Dio-Fatebenefratelli, Brescia, Italy
| | - Simone Lista
- AXA Research Fund & Sorbonne Université Chair, Paris, France; Sorbonne Université, GRC n° 21, Alzheimer Precision Medicine (APM), AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France; Institut du Cerveau et de la Moelle Épiniére (ICM), INSERM U 1127, CNRS UMR 7225, Paris, France; Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France
| | - Marie-Odile Habert
- Département de Médecine Nucléaire, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France; Laboratoire d'Imagerie Biomédicale, Sorbonne Universités, UPMC Univ Paris 06, Inserm U 1146, CNRS UMR 7371, Paris, France
| | - Marie-Claude Potier
- ICM Institut du Cerveau et de la Moelle épinière, CNRS UMR7225, INSERM U1127, UPMC, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Michel J Grothe
- German Center for Neurodegenerative Diseases (DZNE)-Rostock/Greifswald, Rostock, Germany; Department of Psychosomatic Medicine, University of Rostock, Rostock, Germany
| | - Stephane Epelbaum
- Sorbonne Université, GRC n° 21, Alzheimer Precision Medicine (APM), AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Luisa Sambati
- Sorbonne Université, GRC n° 21, Alzheimer Precision Medicine (APM), AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Geoffroy Gagliardi
- Sorbonne Université, GRC n° 21, Alzheimer Precision Medicine (APM), AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Nicola Toschi
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy; Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Michael D Greicius
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
| | - Bruno Dubois
- Sorbonne Université, GRC n° 21, Alzheimer Precision Medicine (APM), AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Harald Hampel
- AXA Research Fund & Sorbonne Université Chair, Paris, France; Sorbonne Université, GRC n° 21, Alzheimer Precision Medicine (APM), AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France; Institut du Cerveau et de la Moelle Épiniére (ICM), INSERM U 1127, CNRS UMR 7225, Paris, France; Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France
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Tiernan CT, Ginsberg SD, Guillozet-Bongaarts AL, Ward SM, He B, Kanaan NM, Mufson EJ, Binder LI, Counts SE. Protein homeostasis gene dysregulation in pretangle-bearing nucleus basalis neurons during the progression of Alzheimer's disease. Neurobiol Aging 2016; 42:80-90. [PMID: 27143424 PMCID: PMC4973891 DOI: 10.1016/j.neurobiolaging.2016.02.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 02/22/2016] [Accepted: 02/28/2016] [Indexed: 12/16/2022]
Abstract
Conformational phosphorylation and cleavage events drive the tau protein from a soluble, monomeric state to a relatively insoluble, polymeric state that precipitates the formation of neurofibrillary tangles (NFTs) in projection neurons in Alzheimer's disease (AD), including the magnocellular perikarya located in the nucleus basalis of Meynert (NBM) complex of the basal forebrain. Whether these structural changes in the tau protein are associated with pathogenic changes at the molecular and cellular level remains undetermined during the onset of AD. Here, we examined alterations in gene expression within individual NBM neurons immunostained for pS422, an early tau phosphorylation event, or dual labeled for pS422 and TauC3, a later stage tau neoepitope, from tissue obtained postmortem from subjects who died with an antemortem clinical diagnosis of no cognitive impairment, mild cognitive impairment, or mild/moderate AD. Specifically, pS422-positive pretangles displayed an upregulation of select gene transcripts subserving protein quality control. On the other hand, late-stage TauC3-positive NFTs exhibited upregulation of messenger RNAs involved in protein degradation but also cell survival. Taken together, these results suggest that molecular pathways regulating protein homeostasis are altered during the evolution of NFT pathology in the NBM. These changes likely contribute to the disruption of protein turnover and neuronal survival of these vulnerable NBM neurons during the progression of AD.
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Affiliation(s)
- Chelsea T Tiernan
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone Medical Center, New York, NY, USA; Department of Neuroscience & Physiology, NYU Langone Medical Center, New York, NY, USA
| | | | - Sarah M Ward
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Bin He
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Nicholas M Kanaan
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Hauenstein Neurosciences Center, Mercy Health Saint Mary's Hospital, Grand Rapids, MI, USA
| | - Elliott J Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Lester I Binder
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Scott E Counts
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Hauenstein Neurosciences Center, Mercy Health Saint Mary's Hospital, Grand Rapids, MI, USA; Department of Family Medicine, Michigan State University, Grand Rapids, MI, USA.
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Teipel SJ, Grothe MJ, Wittfeld K, Hoffmann W, Hegenscheid K, Völzke H, Homuth G, Grabe HJ. Association of a neurokinin 3 receptor polymorphism with the anterior basal forebrain. Neurobiol Aging 2015; 36:2060-7. [PMID: 25976010 DOI: 10.1016/j.neurobiolaging.2014.12.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/06/2014] [Accepted: 12/26/2014] [Indexed: 01/23/2023]
Abstract
The neuropeptide neurokinin 3 (NK3) and its receptor modulate cholinergic activity of the basal forebrain (BF) and are implicated in learning and memory. In Alzheimer's disease, the rs2765 single-nucleotide polymorphism (SNP) of the NK3 receptor-coding gene TACR3 was correlated with the right hippocampus volume. Here, we studied the association of the rs2765 SNP with magnetic resonance imaging-based volumes of the BF and hippocampus in a population-based sample of 1967 participants between 21 and 90 years of age. The rs2765 SNP was significantly associated with the most anterior BF volume corresponding to the medial septum/diagonal band, and with a significantly steeper age-related volume decline. The rs2765 SNP was not associated with other BF subvolumes or hippocampus volumes. Apolipoprotein E ε4 showed no correlation with any brain volume or global cognition. Our findings in a large population-based sample suggest an association of an NK3 receptor SNP with age-related decline of rostral cholinergic BF volume.
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Grothe MJ, Ewers M, Krause B, Heinsen H, Teipel SJ. Basal forebrain atrophy and cortical amyloid deposition in nondemented elderly subjects. Alzheimers Dement 2014; 10:S344-53. [PMID: 24418052 DOI: 10.1016/j.jalz.2013.09.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/09/2013] [Accepted: 09/04/2013] [Indexed: 02/05/2023]
Abstract
BACKGROUND Both neurodegeneration of the cholinergic basal forebrain (BF) and deposition of β-amyloid are early events in the course of Alzheimer's disease (AD). Associations between increased amyloid pathology and cholinergic atrophy have been described in autopsy studies. METHODS We used structural MRI and AV45-PET amyloid imaging data of 225 cognitively normal or mildly impaired elderly subjects from the Alzheimer's Disease Neuroimaging Initiative to assess in vivo associations between BF atrophy and cortical amyloid deposition. Associations were examined using region-of-interest (ROI) and voxel-based approaches with reference to cytoarchitectonic mappings of the cholinergic BF nuclei. RESULTS ROI- and voxel-based approaches yielded complementary evidence for an association between BF volume and cortical amyloid deposition in presymptomatic and predementia stages of AD, irrespective of age, gender, and APOE genotype. CONCLUSIONS The observed correlations between BF atrophy and cortical amyloid load likely reflect associations between cholinergic degeneration and amyloid pathology as reported in neuropathologic examination studies.
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Affiliation(s)
- Michel J Grothe
- German Center for Neurodegenerative Diseases (DZNE), Rostock, Germany.
| | - Michael Ewers
- Institute for Stroke and Dementia Research, Klinikum Grosshadern, Ludwig-Maximilians University, Munich, Germany
| | - Bernd Krause
- Department of Nuclear Medicine, University of Rostock, Rostock, Germany
| | - Helmut Heinsen
- Laboratory of Morphological Brain Research, Department of Psychiatry, University of Würzburg, Würtzburg, Germany
| | - Stefan J Teipel
- German Center for Neurodegenerative Diseases (DZNE), Rostock, Germany; Department of Psychosomatic Medicine, University of Rostock, Rostock, Germany
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Kerbler GM, Hamlin AS, Pannek K, Kurniawan ND, Keller MD, Rose SE, Coulson EJ. Diffusion-weighted magnetic resonance imaging detection of basal forebrain cholinergic degeneration in a mouse model. Neuroimage 2013; 66:133-41. [PMID: 23128077 DOI: 10.1016/j.neuroimage.2012.10.075] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 10/19/2012] [Accepted: 10/26/2012] [Indexed: 11/21/2022] Open
Abstract
Loss of basal forebrain cholinergic neurons is an early and key feature of Alzheimer's disease, and magnetic resonance imaging (MRI) volumetric measurement of the basal forebrain has recently gained attention as a potential diagnostic tool for this condition. The aim of this study was to determine whether loss of basal forebrain cholinergic neurons underpins changes which can be detected through diffusion MRI using diffusion tensor imaging (DTI) and probabilistic tractography in a mouse model. To cause selective basal forebrain cholinergic degeneration, the toxin saporin conjugated to a p75 neurotrophin receptor antibody (mu-p75-SAP) was used. This resulted in ~25% loss of the basal forebrain cholinergic neurons and significant loss of terminal cholinergic projections in the hippocampus, as determined by histology. To test whether lesion of cholinergic neurons caused basal forebrain, hippocampal, or whole brain atrophy, we performed manual segmentation analysis, which revealed no significant atrophy in lesioned animals compared to controls (Rb-IgG-SAP). However, analysis by DTI of the basal forebrain area revealed a significant increase in fractional anisotropy (FA; +7.7%), mean diffusivity (MD; +6.1%), axial diffusivity (AD; +8.5%) and radial diffusivity (RD; +4.0%) in lesioned mice compared to control animals. These parameters strongly inversely correlated with the number of choline acetyl transferase-positive neurons, with FA showing the greatest association (r(2)=0.72), followed by MD (r(2)=0.64), AD (r(2)=0.64) and RD (r(2)=0.61). Moreover, probabilistic tractography analysis of the septo-hippocampal tracts originating from the basal forebrain revealed an increase in streamline MD (+5.1%) and RD (+4.3%) in lesioned mice. This study illustrates that moderate loss of basal forebrain cholinergic neurons (representing only a minor proportion of all septo-hippocampal axons) can be detected by measuring either DTI parameters of the basal forebrain nuclei or tractography parameters of the basal forebrain tracts. These findings provide increased support for using DTI and probabilistic tractography as non-invasive tools for diagnosing and/or monitoring the progression of conditions affecting the integrity of the basal forebrain cholinergic system in humans, including Alzheimer's disease.
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