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Abstract
The analysis of the molecular development of AD (Alzheimer's disease) is technically challenging, due to the chronic nature of the disease, the lack of early and definitive clinical diagnosis, and the fact that the abnormal molecular pathology occurs in the brain. Therefore appropriate animal models of AD are essential if we are to dissect the processes leading to molecular pathology, and ultimately to test the efficacy of potential therapies before clinical studies. Unfortunately, there is controversy over the benefits of the available models, the only consensus of opinion being that no perfect model currently exists. The investigation of animal models is extremely costly and time-consuming, therefore researchers tend to focus on one or two models. For scientists entering the AD research field, it can be difficult to identify the most appropriate model for their needs. Therefore the Models of Dementia: the Good, the Bad and the Future Biochemical Society Focused Meeting provided a platform for discussion and debate on the use and limitations of current models, the most appropriate methods for their characterization and identification of the most pressing needs of the field in general.
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52
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Jabłoński M, Maciejewski R, Januszewski S, Ułamek M, Pluta R. One year follow up in ischemic brain injury and the role of Alzheimer factors. Physiol Res 2011; 60:S113-9. [PMID: 21777016 DOI: 10.33549/physiolres.932186] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Ongoing interest in brain ischemia research has provided data showing that ischemia may be involved in the pathogenesis of Alzheimer disease. Brain ischemia in the rat produces a stereotyped pattern of selective neuronal degeneration, which mimics early Alzheimer disease pathology. The objective of this study was to further develop and characterize cardiac arrest model in rats, which provides practical way to analyze Alzheimer-type neurodegeneration. Rats were made ischemic by cardiac arrest. Blood-brain barrier (BBB) insufficiency, accumulation of different parts of amyloid precursor protein (APP) and platelets inside and outside BBB vessels were investigated in ischemic brain up to 1-year survival. Ischemic brain tissue demonstrated haphazard BBB changes. Toxic fragments of APP deposits were associated with the BBB vessels. Moreover our study revealed platelet aggregates in- and outside BBB vessels. Toxic parts of APP and platelet aggregates correlated very well with BBB permeability. Progressive injury of the ischemic brain parenchyma may be caused not only by a degeneration of neurons destroyed during ischemia but also by chronic damage in BBB. Chronic ischemic BBB insufficiency with accumulation of toxic components of APP in the brain tissue perivascular space, may gradually over a lifetime, progress to brain atrophy and to full blown Alzheimer-type pathology.
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Affiliation(s)
- M Jabłoński
- Department of Ortopedics and Rehabilitation, Lublin Medical University, Lublin, Poland
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53
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Zhang W, Hao J, Liu R, Zhang Z, Lei G, Su C, Miao J, Li Z. Soluble Aβ levels correlate with cognitive deficits in the 12-month-old APPswe/PS1dE9 mouse model of Alzheimer's disease. Behav Brain Res 2011; 222:342-50. [PMID: 21513747 DOI: 10.1016/j.bbr.2011.03.072] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 03/25/2011] [Accepted: 03/30/2011] [Indexed: 10/18/2022]
Abstract
Amyloid-beta peptide (Aβ) is believed to be central in the pathogenesis of Alzheimer's disease (AD) characterized by cognitive deficits. However, it remains uncertain which form(s) of Aβ pathology is responsible for the cognitive deficits in AD. In the present study, the cognitive deficits and the profiles of Aβ pathology were characterized in the 12-month-old APPswe/PS1dE9 double transgenic mice, and their correlations were examined. Compared with non-transgenic littermates, the middle-aged APPswe/PS1dE9 mice exhibited spatial learning and memory deficits in the water maze test and long-term contextual memory deficits in the step-down passive avoidance test. Among the middle-aged APPswe/PS1dE9 mice, hippocampal soluble Aβ1-40 and Aβ1-42 levels were highly correlated with spatial learning deficits and long-term contextual memory deficits, as well as cortical and hippocampal soluble Aβ1-40 and Aβ1-42 levels were strongly correlated with spatial memory deficits. By contrast, no significant correlations were observed between three measures of cognitive functions and amyloid plaque burden (total Aβ plaque load and fibrillar Aβ plaque load), total Aβ levels (Aβ1-40 and Aβ1-42), as well as insoluble Aβ levels (Aβ1-40 and Aβ1-42). Stepwise multiple regression analysis identified hippocampal soluble Aβ1-40 and Aβ1-42 levels as independent factors for predicting the spatial learning deficits and the long-term contextual memory deficits, as well as hippocampal and cortical soluble Aβ1-40 and Aβ1-42 levels as independent factors for predicting the spatial memory deficits in transgenic mice. These results demonstrate that cognitive deficits are highly related to the levels of soluble Aβ in middle-aged APPswe/PS1dE9 mice, in which soluble Aβ levels are only a tiny fraction of the amount of total Aβ levels. Consequently, our findings provide further evidence that soluble Aβ might primarily contribute to cognitive deficits in AD, suggesting that reducing the levels of soluble Aβ species would be a therapeutic intervention for AD patients even with large deposits of aggregated, insoluble Aβ.
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Affiliation(s)
- Wei Zhang
- Department of Neurology, Fourth Military Medical University, Xi'an City, Shaanxi Province 710038, China
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54
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Balducci C, Forloni G. APP transgenic mice: their use and limitations. Neuromolecular Med 2010; 13:117-37. [PMID: 21152995 DOI: 10.1007/s12017-010-8141-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 11/20/2010] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease is the most widespread form of dementia. Its histopathological hallmarks include vascular and extracellular β-amyloid (Aβ) deposition and intraneuronal neurofibrillary tangles (NFTs). Gradual decline of cognitive functions linked to progressive synaptic loss makes patients unable to store new information in the earlier stages of the pathology, later becoming completely dependent because they are unable to do even elementary daily life actions. Although more than a hundred years have passed since Alois Alzheimer described the first case of AD, and despite many years of intense research, there are still many crucial points to be discovered in the neuropathological pathway. The development of transgenic mouse models engineered with overexpression of the amyloid precursor protein carrying familial AD mutations has been extremely useful. Transgenic mice present the hallmarks of the pathology, and histological and behavioural examination supports the amyloid hypothesis. As in human AD, extracellular Aβ deposits surrounded by activated astrocytes and microglia are typical features, together with synaptic and cognitive defects. Although animal models have been widely used, they are still being continuously developed in order to recapitulate some missing aspects of the disease. For instance, AD therapeutic agents tested in transgenic mice gave encouraging results which, however, were very disappointing in clinical trials. Neuronal cell death and NFTs typical of AD are much harder to replicate in these mice, which thus offer a fundamental but still imperfect tool for understanding and solving dementia pathology.
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Affiliation(s)
- Claudia Balducci
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, via G. La Masa, 19, 20156, Milan, Italy.
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55
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Mouse models of neurological disorders—A comparison of heritable and acquired traits. Biochim Biophys Acta Mol Basis Dis 2010; 1802:785-95. [DOI: 10.1016/j.bbadis.2010.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 05/17/2010] [Accepted: 05/19/2010] [Indexed: 01/17/2023]
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56
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Protein disulfide isomerase-immunopositive inclusions in patients with Alzheimer disease. Brain Res 2010; 1349:90-6. [DOI: 10.1016/j.brainres.2010.06.016] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 06/07/2010] [Accepted: 06/07/2010] [Indexed: 11/19/2022]
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57
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Philipson O, Lord A, Gumucio A, O'Callaghan P, Lannfelt L, Nilsson LNG. Animal models of amyloid-beta-related pathologies in Alzheimer's disease. FEBS J 2010; 277:1389-409. [PMID: 20136653 DOI: 10.1111/j.1742-4658.2010.07564.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In the early 1990s, breakthrough discoveries on the genetics of Alzheimer's disease led to the identification of missense mutations in the amyloid-beta precursor protein gene. Research findings quickly followed, giving insights into molecular pathogenesis and possibilities for the development of new types of animal models. The complete toolbox of transgenic techniques, including pronuclear oocyte injection and homologous recombination, has been applied in the Alzheimer's disease field, to produce overexpressors, knockouts, knockins and regulatable transgenics. Transgenic models have dramatically advanced our understanding of pathogenic mechanisms and allowed therapeutic approaches to be tested. Following a brief introduction to Alzheimer's disease, various nontransgenic and transgenic animal models are described in terms of their values and limitations with respect to pathogenic, therapeutic and functional understandings of the human disease.
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Affiliation(s)
- Ola Philipson
- Department of Public Health and Caring Sciences/Molecular Geriatrics, Uppsala University, Sweden
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58
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Epis R, Gardoni F, Marcello E, Genazzani A, Canonico PL, Di Luca M. Searching for new animal models of Alzheimer's disease. Eur J Pharmacol 2009; 626:57-63. [PMID: 19836370 DOI: 10.1016/j.ejphar.2009.10.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 10/06/2009] [Accepted: 10/07/2009] [Indexed: 10/20/2022]
Abstract
The pathophysiology of chronic neurodegenerative diseases, as Alzheimer's diseases, has remained inaccessible till recently. But this situation is changing quickly. In the past decades, genes causing familiar forms of the disease have been identified and provided the genetic framework for the emerging amyloid hypothesis. On the basis of these findings, engineered mouse models have been developed and have allowed the understanding of crucial information about the pathogenic process. Certain observations obtained by transgenic mice, however, do not easily fit with the simplest version of the amyloid hypothesis. Even if there are transgenic lines that offer robust and relatively faithful reproductions of a subset of Alzheimer's disease's features, a mouse model that recapitulates all aspects of the disease has not yet been produced. Several still not completely known factors combine to produce highly variability across transgenic mouse models. Discrepancies in neuropathology and behaviour between transgenic mouse models and human Alzheimer's disease, and among different transgenic-lines, suggest caution in the interpretation of the results. Here we try to analyze critically some of the information provided by transgenic mice but ascertaining which elements of the neuropathological and behavioural phenotype of these various strains of transgenic mice are relevant to that observed in Alzheimer's disease continues to be a challenge.
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Affiliation(s)
- Roberta Epis
- Department of Pharmacological Sciences and Centre of Excellence on Neurodegenerative Diseases. University of Milan, Via Balzaretti 9, 20133 Milan, Italy
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59
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Giuliani F, Vernay A, Leuba G, Schenk F. Decreased behavioral impairments in an Alzheimer mice model by interfering with TNF-alpha metabolism. Brain Res Bull 2009; 80:302-8. [DOI: 10.1016/j.brainresbull.2009.07.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 07/09/2009] [Accepted: 07/10/2009] [Indexed: 11/27/2022]
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60
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Blanchard J, Decorte L, Noguès X, Micheau J. Characterization of cognition alteration across the course of the disease in APP751SL mice with parallel estimation of cerebral Abeta deposition. Behav Brain Res 2009; 201:147-57. [PMID: 19428628 DOI: 10.1016/j.bbr.2009.02.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Accepted: 02/04/2009] [Indexed: 11/26/2022]
Abstract
Current transgenic mouse models of Alzheimer disease constitute a relevant tool to examine the relationships between neuropathological lesions, neurodegeneration and clinical syndromes. Nevertheless, addressing the relation between Abeta deposition and cognition deterioration requires careful adjustment for age to decipher underlying mechanisms of impairments and identify potential therapeutic targets. In the present work we have carried out a detailed behavioral analysis of the APP(751SL) transgenic mouse model testing 6 age-points (from 2 to 19-20 months) and estimating in parallel the cerebral Abeta deposition. The immunohistochemistry study indicated a fast progression of Abeta(17-24) staining in several brain structures that reached for most of them, a maximal level at 7-8 months of age. Behavioral experiments showed that APP(751SL) mice displayed alterations in some general functions (muscular strength, motor activity) whereas other functions are preserved (anxiety, exploration). Acquisition and extinction of an appetitive operant conditioning were used to assess early learning deficits. Hippocampal but not dorso-lateral striatal lesion was shown to delay extinction. Although some learning deficits were detected at 5-6 months in the acquisition of the operant conditioning task, more robust impairments in extinction were observed in 7-8-month-old mice. Indeed, spatial memory deficit was associated to a selective hippocampal CA1 impairment of learning-induced Zif268 activation. Because this mouse model displayed gradual memory deficits it gives the opportunity to investigate the temporal progression of molecular and cellular mechanisms that induce cognitive decline.
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Affiliation(s)
- Julie Blanchard
- Centre for Integrative and Cognitive Neuroscience, University of Bordeaux, CNRS UMR 5228, Talence, France
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61
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Colton CA, Wilcock DM, Wink DA, Davis J, Van Nostrand WE, Vitek MP. The effects of NOS2 gene deletion on mice expressing mutated human AbetaPP. J Alzheimers Dis 2008; 15:571-87. [PMID: 19096157 PMCID: PMC2667339 DOI: 10.3233/jad-2008-15405] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nitric oxide synthase 2 (NOS2) and its gene product, inducible NOS (iNOS) play an important role in neuroinflammation by generating nitric oxide (NO), a critical signaling and redox factor in the brain. Although NO is associated with tissue damage, it can also promote cell survival. We hypothesize that during long-term exposure to amyloid-beta (Abeta) in Alzheimer's disease (AD), NO levels fall in the brain to a threshold at which the protective effects of NO cannot be sustained, promoting Abeta mediated damage. Two new mouse models of AD have been developed that utilize this concept of NO's action. These mice express human amyloid-beta protein precursor (AbetaPP) mutations that generate Abeta peptides on a mouse NOS2 knockout background. The APP/NOS2(-/-) bigenic mice progress from Abeta production and amyloid deposition to hyperphosphorylated normal mouse tau at AD-associated epitopes, aggregation and redistribution of tau to somatodendritic regions of neurons and significant neuronal loss including loss of interneurons. This AD-like pathology is accompanied by robust behavioral changes. As APP/NOS2(-/-) bigenic mice more fully model the human AD disease pathology, they may serve as a tool to better understand disease progression in AD and the role of NO in altering chronic neurological disease processes.
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Affiliation(s)
- Carol A Colton
- Division of Neurology, Duke University Medical Center, Durham, NC 27710, USA.
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62
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Increased exploratory activity of APP23 mice in a novel environment is reversed by siRNA. Brain Res 2008; 1243:124-33. [DOI: 10.1016/j.brainres.2008.09.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 09/06/2008] [Accepted: 09/11/2008] [Indexed: 12/11/2022]
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63
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Simón AM, Schiapparelli L, Salazar-Colocho P, Cuadrado-Tejedor M, Escribano L, López de Maturana R, Del Río J, Pérez-Mediavilla A, Frechilla D. Overexpression of wild-type human APP in mice causes cognitive deficits and pathological features unrelated to Abeta levels. Neurobiol Dis 2008; 33:369-78. [PMID: 19101630 DOI: 10.1016/j.nbd.2008.11.005] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 10/30/2008] [Accepted: 11/07/2008] [Indexed: 01/07/2023] Open
Abstract
Transgenic mice expressing mutant human amyloid precursor protein (APP) develop an age-dependent amyloid pathology and memory deficits, but no overt neuronal loss. Here, in mice overexpressing wild-type human APP (hAPP(wt)) we found an early memory impairment, particularly in the water maze and to a lesser extent in the object recognition task, but beta-amyloid peptide (Abeta(42)) was barely detectable in the hippocampus. In these mice, hAPP processing was basically non-amyloidogenic, with high levels of APP carboxy-terminal fragments, C83 and APP intracellular domain. A tau pathology with an early increase in the levels of phosphorylated tau in the hippocampus, a likely consequence of enhanced ERK1/2 activation, was also observed. Furthermore, these mice presented a loss of synapse-associated proteins: PSD95, AMPA and NMDA receptor subunits and phosphorylated CaMKII. Importantly, signs of neurodegeneration were found in the hippocampal CA1 subfield and in the entorhinal cortex that were associated to a marked loss of MAP2 immunoreactivity. Conversely, in mice expressing mutant hAPP, high levels of Abeta(42) were found in the hippocampus, but no signs of neurodegeneration were apparent. The results support the notion of Abeta-independent pathogenic pathways in Alzheimer's disease.
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Affiliation(s)
- Ana-María Simón
- Division of Neurosciences, CIMA, University of Navarra, Av. Pio XII 55, 31008 Pamplona, Spain
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64
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Spires-Jones TL, Mielke ML, Rozkalne A, Meyer-Luehmann M, de Calignon A, Bacskai BJ, Schenk D, Hyman BT. Passive immunotherapy rapidly increases structural plasticity in a mouse model of Alzheimer disease. Neurobiol Dis 2008; 33:213-20. [PMID: 19028582 DOI: 10.1016/j.nbd.2008.10.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Revised: 10/09/2008] [Accepted: 10/13/2008] [Indexed: 11/15/2022] Open
Abstract
Senile plaque-associated changes in neuronal connectivity such as altered neurite trajectory, dystrophic swellings, and synapse and dendritic spine loss are thought to contribute to cognitive dysfunction in Alzheimer's disease and mouse models. Immunotherapy to remove amyloid beta is a promising therapy that causes recovery of neurite trajectory and dystrophic neurites over a period of days. The acute effects of immunotherapy on neurite morphology at a time point when soluble amyloid has been cleared but dense plaques are not yet affected are unknown. To examine whether removal of soluble amyloid beta (Abeta) has a therapeutic effect on dendritic spines, we explored spine dynamics within 1 h of applying a neutralizing anti Abeta antibody. This acute treatment caused a small but significant increase in dendritic spine formation in PDAPP brain far from plaques, without affecting spine plasticity near plaques or average dendritic spine density. These data support the hypothesis that removing toxic soluble forms of amyloid-beta rapidly increases structural plasticity possibly allowing functional recovery of neural circuits.
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Affiliation(s)
- Tara L Spires-Jones
- MassGeneral Institute for Neurodegenerative Disease, Harvard Medical School, Charlestown, MA, USA
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65
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Abstract
In Alzheimer's disease (AD), characteristic lesions develop in brain regions that subserve cognitive functions, ultimately leading to dementia. There are now several lesioned or transgenic small-animal models of the disease that model select aspects of cognitive deficits and/or recapitulate many, but not all, of the characteristic pathologic lesions observed in AD. This overview describes the most common approaches used to model AD in rodents, highlights their utility, and discusses some of their deficiencies.
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66
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Cassel JC, Mathis C, Majchrzak M, Moreau PH, Dalrymple-Alford JC. Coexisting cholinergic and parahippocampal degeneration: a key to memory loss in dementia and a challenge for transgenic models? NEURODEGENER DIS 2008; 5:304-17. [PMID: 18520165 DOI: 10.1159/000135615] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Accepted: 10/31/2007] [Indexed: 12/25/2022] Open
Abstract
One century after Alzheimer's initial report, a variety of animal models of Alzheimer's disease (AD) are being used to mimic one or more pathological signs viewed as critical for the evolution of cognitive decline in dementia. Among the most common are, (a) traditional lesion models aimed at reproducing the degeneration of one of two key brain regions affected in AD, namely the cholinergic basal forebrain (CBF) and the transentorhinal region, and (b) transgenic mouse models aimed at reproducing AD histopathological hallmarks, namely amyloid plaques and neurofibrillary tangles. These models have provided valuable insights into the development and consequences of the pathology, but they have not consistently reproduced the severity of memory deficits exhibited in AD. The reasons for this lack of correspondence with the severity of expected deficits may include the limited replication of multiple neuropathology in potentially key brain regions. A recent lesion model in the rat found that severe memory impairment was obtained only when the two traditional lesions were combined together (i.e. conjoint CBF and entorhinal cortex lesions), indicative of a dramatic impact on cognitive function when there is coexisting, rather than isolated, damage in these two brain regions. It is proposed that combining AD transgenic mouse models with additional experimental damage to both the CBF and entorhinal regions might provide a unique opportunity to further understand the evolution of the disease and improve treatments of severe cognitive dysfunction in neurodegenerative dementias.
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Affiliation(s)
- Jean-Christophe Cassel
- LINC UMR 7191, Université Louis Pasteur, CNRS, Institut Fédératif de Recherche IFR 37, GDR CNRS 2905, Strasbourg, France.
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67
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Kobayashi D, Zeller M, Cole T, Buttini M, McConlogue L, Sinha S, Freedman S, Morris RGM, Chen KS. BACE1 gene deletion: Impact on behavioral function in a model of Alzheimer's disease. Neurobiol Aging 2008; 29:861-73. [PMID: 17331621 DOI: 10.1016/j.neurobiolaging.2007.01.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Revised: 11/15/2006] [Accepted: 01/13/2007] [Indexed: 10/23/2022]
Abstract
Accumulation of cerebral amyloid-beta (Abeta) has been implicated as a putative causal factor in the development of Alzheimer's disease (AD). Transgenic mice like the PDAPP line overexpress human mutant Amyloid Precursor Protein (hAPP) and recapitulate many features of AD, including amyloid neuropathology and cognitive deficits. Inhibition of the beta-site aspartyl cleaving enzyme (BACE1) enzyme responsible for the first proteolytic cleavage that ultimately generates Abeta has been proposed as a strategy for AD therapy. To assess the theoretical repercussions of beta-secretase activity reduction in an in vivo model of AD, BACE1(-/-) mice bred to the PDAPP line were examined in a series of behavioral tasks. Although BACE1 gene ablation abolished hAbeta accumulation, BACE1(-/-) mice had unexpected sensorimotor impairments, spatial memory deficits, and displayed seizures, phenotypes which were severe on the PDAPP background. These results suggest that while excess Abeta is functionally pathological, BACE1-mediated processing of APP and other substrates play a role in "normal" learning, memory and sensorimotor processes.
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Affiliation(s)
- Dione Kobayashi
- Rinat Neurosciences, 230 East Grand Avenue, South San Francisco, CA 94080, USA.
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68
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The regular and light-dark Suok tests of anxiety and sensorimotor integration: utility for behavioral characterization in laboratory rodents. Nat Protoc 2008; 3:129-36. [PMID: 18193029 DOI: 10.1038/nprot.2007.516] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Animal behavioral models are crucial for neurobiological research, allowing for the thorough investigation of brain pathogenesis to be performed. In both animals and humans, anxiety has long been linked to vestibular disorders. However, although there are many tests of anxiety and vestibular deficits, there are few protocols that address the interplay between these two domains. The Suok test and its light-dark modification presented here appear to be suitable for testing this pathogenetic link in laboratory rodents. This protocol adds a new dimension to previously used tests by assessing animal anxiety and balancing simultaneously, resulting in efficient, high-throughput screens for testing psychotropic drugs, phenotyping genetically modified animals, and modeling clusters of human disorders related to stress/anxiety and balancing.
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69
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Duyckaerts C, Potier MC, Delatour B. Alzheimer disease models and human neuropathology: similarities and differences. Acta Neuropathol 2008; 115:5-38. [PMID: 18038275 PMCID: PMC2100431 DOI: 10.1007/s00401-007-0312-8] [Citation(s) in RCA: 276] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2007] [Revised: 10/13/2007] [Accepted: 10/14/2007] [Indexed: 12/02/2022]
Abstract
Animal models aim to replicate the symptoms, the lesions or the cause(s) of Alzheimer disease. Numerous mouse transgenic lines have now succeeded in partially reproducing its lesions: the extracellular deposits of Abeta peptide and the intracellular accumulation of tau protein. Mutated human APP transgenes result in the deposition of Abeta peptide, similar but not identical to the Abeta peptide of human senile plaque. Amyloid angiopathy is common. Besides the deposition of Abeta, axon dystrophy and alteration of dendrites have been observed. All of the mutations cause an increase in Abeta 42 levels, except for the Arctic mutation, which alters the Abeta sequence itself. Overexpressing wild-type APP alone (as in the murine models of human trisomy 21) causes no Abeta deposition in most mouse lines. Doubly (APP x mutated PS1) transgenic mice develop the lesions earlier. Transgenic mice in which BACE1 has been knocked out or overexpressed have been produced, as well as lines with altered expression of neprilysin, the main degrading enzyme of Abeta. The APP transgenic mice have raised new questions concerning the mechanisms of neuronal loss, the accumulation of Abeta in the cell body of the neurons, inflammation and gliosis, and the dendritic alterations. They have allowed some insight to be gained into the kinetics of the changes. The connection between the symptoms, the lesions and the increase in Abeta oligomers has been found to be difficult to unravel. Neurofibrillary tangles are only found in mouse lines that overexpress mutated tau or human tau on a murine tau -/- background. A triply transgenic model (mutated APP, PS1 and tau) recapitulates the alterations seen in AD but its physiological relevance may be discussed. A number of modulators of Abeta or of tau accumulation have been tested. A transgenic model may be analyzed at three levels at least (symptoms, lesions, cause of the disease), and a reading key is proposed to summarize this analysis.
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Affiliation(s)
- Charles Duyckaerts
- Laboratoire de Neuropathologie Raymond Escourolle, Hôpital de La Salpêtrière, 47 Boulevard de l'Hôpital, 75651, Paris Cedex 13, France.
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70
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Morgan D. Amyloid, memory and neurogenesis. Exp Neurol 2007; 205:330-5. [PMID: 17445801 DOI: 10.1016/j.expneurol.2007.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 02/22/2007] [Accepted: 03/06/2007] [Indexed: 10/23/2022]
Abstract
Transgenic mouse models of amyloid deposition consistently demonstrate impaired performance on certain tasks of learning and memory. The article by Zhang et al. (2006) demonstrates reductions in dentate gyrus neurogenesis in a murine model of amyloid deposition which is linked to the deposition of amyloid and not overexpression of transgenes. Neurogenesis plays at least a facilitatory role in the formation of memory, the nature of which is only beginning to emerge. Thus, it seems reasonable to propose that the memory deficits found in the amyloid precursor protein transgenic mouse models of amyloid deposition result, at least in part, from reduced rates of hippocampal neurogenesis. The possible relationship to memory loss in Alzheimer's dementia is also discussed.
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Affiliation(s)
- Dave Morgan
- Alzheimer Research Laboratory, Department of Molecular Pharmacology and Physiology, School of Basic Biomedical Sciences, College of Medicine, 12901 BB Downs Blvd. MDC Box 9, University of South Florida, Tampa, FL 33612, USA.
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71
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Dere E, Huston JP, De Souza Silva MA. The pharmacology, neuroanatomy and neurogenetics of one-trial object recognition in rodents. Neurosci Biobehav Rev 2007; 31:673-704. [PMID: 17368764 DOI: 10.1016/j.neubiorev.2007.01.005] [Citation(s) in RCA: 524] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 01/08/2007] [Accepted: 01/18/2007] [Indexed: 01/31/2023]
Abstract
Rats and mice are attracted by novel objects. They readily approach novel objects and explore them with their vibrissae, nose and forepaws. It is assumed that such a single explorative episode leaves a lasting and complex memory trace, which includes information about the features of the object explored, as well as where and even when the object was encountered. Indeed, it has been shown that rodents are able to discriminate a novel from a familiar object (one-trial object recognition), can detect a mismatch between the past and present location of a familiar object (one-trial object-place recognition), and can discriminate different objects in terms of their relative recency (temporal order memory), i.e., which one of two objects has been encountered earlier. Since the novelty-preference paradigm is very versatile and has some advantages compared to several other memory tasks, such as the water maze, it has become a powerful tool in current neurophamacological, neuroanatomical and neurogenetical memory research using both rats and mice. This review is intended to provide a comprehensive summary on key findings delineating the brain structures, neurotransmitters, molecular mechanisms and genes involved in encoding, consolidation, storage and retrieval of different forms of one-trial object memory in rats and mice.
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Affiliation(s)
- Ekrem Dere
- Institute of Physiological Psychology, and Center for Biological and Medical Research, Heinrich-Heine-University of Düsseldorf, Düsseldorf, Germany.
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72
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Eriksen JL, Janus CG. Plaques, tangles, and memory loss in mouse models of neurodegeneration. Behav Genet 2006; 37:79-100. [PMID: 17072762 DOI: 10.1007/s10519-006-9118-z] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Accepted: 09/21/2006] [Indexed: 10/24/2022]
Abstract
Within the past decade, our understanding of the pathogenic mechanisms in Alzheimer's disease (AD) has dramatically advanced because of the development of transgenic mouse models that recapitulate the key pathological and behavioral phenotypes of the disease. These mouse models have allowed investigators to test detailed questions about how pathology develops and to evaluate potential therapeutic approaches that could slow down the development of this disease. In this review, we discuss the status of transgenic mouse models and review the complex relationship between pathology and behavior in the development of neuropathological syndromes in AD.
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Affiliation(s)
- Jason L Eriksen
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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73
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Arshavsky YI. Alzheimer's disease, brain immune privilege and memory: a hypothesis. J Neural Transm (Vienna) 2006; 113:1697-707. [PMID: 16932992 DOI: 10.1007/s00702-006-0524-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Accepted: 04/28/2006] [Indexed: 12/13/2022]
Abstract
The most distinctive feature of Alzheimer's disease (AD) is the specific degeneration of the neurons involved in memory consolidation, storage, and retrieval. Patients suffering from AD forget basic information about their past, loose linguistic and calculative abilities and communication skills. Thus, understanding the etiology of AD may provide insights into the mechanisms of memory and vice versa. The brain is an immunologically privileged site protected from the organism's immune reactions by the blood-brain barrier (BBB). All risk factors for AD (both cardiovascular and genetic) lead to destruction of the BBB. Evidence emerging from recent literature indicates that AD may have an autoimmune nature associated with BBB impairments. This hypothesis suggests that the process of memory consolidation involves the synthesis of novel macromolecules recognized by the immune system as "non-self" antigens. The objective of this paper is to stimulate new approaches to studies of neural mechanisms underpinning memory consolidation and its breakdown during AD. If the hypothesis on the autoimmune nature of AD is correct, the identification of the putative antigenic macromolecules might be critical to understanding the etiology and prevention of AD, as well as for elucidating cellular mechanisms of learning and memory.
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Affiliation(s)
- Y I Arshavsky
- Institute for Nonlinear Science, University of California San Diego, La Jolla, CA 92093-0402, USA.
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74
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Kalinin S, Gavrilyuk V, Polak PE, Vasser R, Zhao J, Heneka MT, Feinstein DL. Noradrenaline deficiency in brain increases beta-amyloid plaque burden in an animal model of Alzheimer's disease. Neurobiol Aging 2006; 28:1206-14. [PMID: 16837104 DOI: 10.1016/j.neurobiolaging.2006.06.003] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Revised: 05/26/2006] [Accepted: 06/02/2006] [Indexed: 12/18/2022]
Abstract
Loss of Locus coeruleus (LC) noradrenergic (NA) neurons occurs in several neurodegenerative conditions including Alzheimer's disease (AD). In vitro and in vivo studies have shown that NA influences several features of AD disease including inflammation, neurodegeneration, and cognitive function. In the current study we tested if LC loss influenced beta amyloid (Abeta) plaque deposition. LC neuronal degeneration was induced in transgenic mice expressing mutant V717F human amyloid precursor protein (APP) by treatment with the selective neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine DSP4 (5mg/kg every 2 weeks beginning at age 3 months). At 9 months of age, when control mice show low amyloid load, DSP4-treated mice showed an approximately 5-fold increase in the average number of Abeta plaques. This was accompanied by an increase in the levels of APP C-terminal cleavage fragments. DSP4-treatment increased both microglial and astroglial activation. In vivo, DSP4-treatment decreased expression and activity of the Abeta degrading enzyme neprilysin, while in vitro NA increased phagocytosis of Abeta1-42 by microglia. These findings suggest that noradrenergic innervation from LC are needed to maintain adequate Abeta clearance, and therefore that LC degeneration could contribute to AD pathogenesis.
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Affiliation(s)
- Sergey Kalinin
- Department of Anesthesiology, University of Illinois, & Jesse Brown Veteran's Affairs Research Division, Chicago, IL 60612, United States
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75
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Kuc KA, Gregersen BM, Gannon KS, Dodart JC. Holeboard discrimination learning in mice. GENES BRAIN AND BEHAVIOR 2006; 5:355-63. [PMID: 16716205 DOI: 10.1111/j.1601-183x.2005.00168.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have adapted to mice a holeboard-learning task, which allows simultaneous assessment of spatial working and reference-memory performance. The holeboard apparatus consists of an open-field chamber with a 16-hole floor insert. Across trials, animals have to learn that the same four holes of 16 are always baited. Here, we show that C57BL/6 mice readily acquire this task within 4 days when submitted to six trials per day or within 8 days when submitted to only four trials per day. We also show that C57BL/6, Swiss-Webster, CD-1 and DBA/2 mice acquire this task similarly, despite the fact that some differences could be observed in measures of exploratory activity during habituation and training. Moreover, the muscarinic antagonist scopolamine disrupts learning at doses of 0.1 and 1.0 mg/kg, although the highest dose appeared to have side-effects. Lastly, we found that amyloid precursor protein transgenic mice have a selective disruption in their working-memory performance only during reversal training (i.e. after a change in the configuration of the baited holes). Overall, our data indicate that this spatial learning task is well adapted to mice and will be useful to characterize spatial memory in various genetic or pharmacological mouse models.
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Affiliation(s)
- K A Kuc
- Eli Lilly and Company, Neuroscience Discovery Research, Indianapolis, IN 46285, USA
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76
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Donovan MH, Yazdani U, Norris RD, Games D, German DC, Eisch AJ. Decreased adult hippocampal neurogenesis in the PDAPP mouse model of Alzheimer's disease. J Comp Neurol 2006; 495:70-83. [PMID: 16432899 DOI: 10.1002/cne.20840] [Citation(s) in RCA: 285] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Abnormal subgranular zone (SGZ) neurogenesis is proposed to contribute to Alzheimer's disease (AD)-related decreases in hippocampal function. Our goal was to examine hippocampal neurogenesis in the PDAPP mouse, a model of AD with age-dependent accumulation of amyloid-beta(42) (Abeta(42))-containing plaques that is well studied with regard to AD therapies. A secondary goal was to determine whether altered neurogenesis in the PDAPP mouse is associated with abnormal maturation or number of mature cells. A tertiary goal was to provide insight into why hippocampal neurogenesis appears to be increased in AD post-mortem tissue and decreased in most AD mouse models. We report an age-dependent decrease in SGZ proliferation in homozygous PDAPP mice. At 1 year of age, PDAPP mice also had new dentate gyrus granule neurons with abnormal maturation and fewer dying cells relative to control mice. In contrast to decreased SGZ cell birth, PDAPP mice had increased birth of immature neurons in the outer portion of the granule cell layer (oGCL), providing insight into why some studies link AD with increased neurogenesis. However, these ectopic oGCL cells were still rare compared with SGZ proliferating cells, emphasizing that the primary characteristic of PDAPP mice is decreased neurogenesis. The decrease in SGZ neurogenesis was not associated with an age-dependent loss of dentate granule neurons. The altered neurogenesis in the PDAPP mouse may contribute to the age-related cognitive deficits reported in this model of AD and may be a useful adjunct target for assessing the impact of AD therapies.
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Affiliation(s)
- Michael H Donovan
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9070, USA
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77
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Hartman RE, Izumi Y, Bales KR, Paul SM, Wozniak DF, Holtzman DM. Treatment with an amyloid-beta antibody ameliorates plaque load, learning deficits, and hippocampal long-term potentiation in a mouse model of Alzheimer's disease. J Neurosci 2006; 25:6213-20. [PMID: 15987951 PMCID: PMC6725066 DOI: 10.1523/jneurosci.0664-05.2005] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
PDAPP transgenic mice overexpress a mutant form of human amyloid precursor protein under control of the platelet-derived growth factor promoter in CNS neurons that causes early onset, familial Alzheimer's disease in humans. These mice, on a mixed genetic background, have been shown to have substantial learning impairments from early ages, as well as an age-dependent decline in learning ability that has been hypothesized to be caused by amyloid-beta (Abeta) accumulation. The goals of this study were to determine: (1) whether PDAPP mice on a pure C57BL/6 background develop more severe age-dependent learning deficits than wild-type mice; (2) if so, whether Abeta accumulation accounts for the excessive decline in learning ability; and (3) whether the learning deficits are reversible, even after significant Abeta deposition. At 4-6, 10-12, or 17-19 months of age, PDAPP and littermate wild-type mice on a C57BL/6 background were tested on a 5 week water maze protocol in which the location of the escape platform changed weekly, requiring the mice to repeatedly learn new information. PDAPP mice exhibited impaired spatial learning as early as 4 months (pre-Abeta deposition), and the performance of both wild-type and PDAPP mice declined with age. However, PDAPP mice exhibited significantly greater deterioration with age. Direct evidence for the role of Abeta accumulation in the age-related worsening in PDAPP mice was provided by the observation that systemic treatment over several weeks with the anti-Abeta antibody 10D5 reduced plaque deposition, increased plasma Abeta, improved hippocampal long-term potentiation, and improved behavioral performance in aged PDAPP mice with substantial Abeta burden.
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Affiliation(s)
- Richard E Hartman
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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78
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Hale G, Good M. Impaired visuospatial recognition memory but normal object novelty detection and relative familiarity judgments in adult mice expressing the APPswe Alzheimer's disease mutation. Behav Neurosci 2006; 119:884-91. [PMID: 16187817 DOI: 10.1037/0735-7044.119.4.884] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present study examined the effects of a human APPswe mutation on object recognition memory in adult Tg2576 mice. The results showed that 14-month old Tg2576 mice were able to detect object novelty as well as control mice, even with delays of up to 24 hr. In addition, transgenic mice showed a normal recency effect and explored the most recently encountered object significantly less than an object encountered earlier in a trial. However, adult Tg2576 mice showed impairments in detecting a change in the relative positions of an array of familiar objects. The results suggest that the formation of representations involving a combination of object identity and spatial information are particularly sensitive to amyloid pathology in adult APPswe mutant mice.
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Affiliation(s)
- Gemma Hale
- School of Psychology, Cardiff University, Cardiff, United Kingdom
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79
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Hellweg R, Lohmann P, Huber R, Kühl A, Riepe MW. Spatial navigation in complex and radial mazes in APP23 animals and neurotrophin signaling as a biological marker of early impairment. Learn Mem 2006; 13:63-71. [PMID: 16418433 PMCID: PMC1360134 DOI: 10.1101/lm.2606] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Impairment of hippocampal function precedes frontal and parietal cortex impairment in human Alzheimer's disease (AD). Neurotrophins are critical for behavioral performance and neuronal survival in AD. We used complex and radial mazes to assess spatial orientation and learning in wild-type and B6-Tg(ThylAPP)23Sdz (APP23) animals, a transgenic mouse model of AD. We also assessed brain content of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3). Performance was alike in wild-type and APP23 animals in the radial maze. In contrast, performance in the complex maze was better in wild-type than APP23 animals. Contrary to the wild-type, hippocampal BDNF levels decreased on training in APP23 animals. Hippocampal and frontal cortex NGF levels in APP23 animals correlated with the time to solve the complex maze, but correlated inversely with escape time in wild-type animals. NT-3 levels were alike in wild-type and APP23 animals and were unchanged even after training. Both types of mazes depend on hippocampal integrity to some extent. However, according to the cognitive mapping theory of spatial learning, the complex maze because of the increased complexity of the environment most likely depends more strongly on preserved hippocampal function than the radial maze in the working memory configuration applied here. Greater impairment in complex maze performance than in radial maze performance thus resembles the predominant affliction of the loss of hippocampal function in human AD. NGF and BDNF levels on maze learning are different in wild-type and transgenic animals, indicating that biological markers of AD may be altered on challenge even though equilibrium levels are alike.
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Affiliation(s)
- Rainer Hellweg
- Department of Psychiatry, Charité University, 14050 Berlin, Germany
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80
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Brody DL, Holtzman DM. Morris water maze search strategy analysis in PDAPP mice before and after experimental traumatic brain injury. Exp Neurol 2005; 197:330-40. [PMID: 16309676 PMCID: PMC1913184 DOI: 10.1016/j.expneurol.2005.10.020] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Revised: 09/13/2005] [Accepted: 10/12/2005] [Indexed: 11/23/2022]
Abstract
Traumatic brain injury (TBI) is a common cause of cognitive dysfunction and a major risk factor for Alzheimer's disease (AD). PDAPP mice, a transgenic line overexpressing a mutant human amyloid precursor protein (APP) implicated in familial AD, have markedly impaired behavioral performance in the Morris water maze relative to wild-type (WT) littermates. Performance further deteriorates following experimental TBI in both PDAPP and WT mice. However, the aspects of cognitive function involved are not well understood. Here, we have analyzed search strategies used in the water maze by 3-4 month old PDAPP and WT C57Bl6 littermates both before and after moderate controlled cortical impact TBI. Prior to TBI, PDAPP mice used less spatial strategies and more nonspatial systematic strategies and strategies involving repetitive looping than WT mice. With training, PDAPP mice used more spatial strategies and less repetitive looping. After TBI, PDAPP mice lost use of spatial strategies and relied more on repetitive looping. TBI in WT mice also reduced their use of spatial strategies but instead caused a switch to nonspatial systematic strategies. We also analyzed changes in the efficiency with which mice used each individual strategy, but found that differences in which strategies were used quantitatively accounted for most of the differences in performance between groups. These results demonstrate that suboptimal search strategy use in addition to effects on spatial learning and memory underlies the impaired performance of PDAPP mice and further deterioration following TBI. Human TBI patients may have analogous poor use of problem solving strategies.
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Affiliation(s)
- David L Brody
- Department of Neurology, Washington University, 660 S. Euclid Ave., Box 8111, St. Louis, MO 63110, USA.
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81
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Rossi D, Brambilla L, Valori CF, Crugnola A, Giaccone G, Capobianco R, Mangieri M, Kingston AE, Bloc A, Bezzi P, Volterra A. Defective tumor necrosis factor-alpha-dependent control of astrocyte glutamate release in a transgenic mouse model of Alzheimer disease. J Biol Chem 2005; 280:42088-96. [PMID: 16253995 DOI: 10.1074/jbc.m504124200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cytokine tumor necrosis factor-alpha (TNFalpha) induces Ca2+-dependent glutamate release from astrocytes via the downstream action of prostaglandin (PG) E2. By this process, astrocytes may participate in intercellular communication and neuromodulation. Acute inflammation in vitro, induced by adding reactive microglia to astrocyte cultures, enhances TNFalpha production and amplifies glutamate release, switching the pathway into a neurodamaging cascade (Bezzi, P., Domercq, M., Brambilla, L., Galli, R., Schols, D., De Clercq, E., Vescovi, A., Bagetta, G., Kollias, G., Meldolesi, J., and Volterra, A. (2001) Nat. Neurosci. 4, 702-710). Because glial inflammation is a component of Alzheimer disease (AD) and TNFalpha is overexpressed in AD brains, we investigated possible alterations of the cytokine-dependent pathway in PDAPP mice, a transgenic model of AD. Glutamate release was measured in acute hippocampal and cerebellar slices from mice at early (4-month-old) and late (12-month-old) disease stages in comparison with age-matched controls. Surprisingly, TNFalpha-evoked glutamate release, normal in 4-month-old PDAPP mice, was dramatically reduced in the hippocampus of 12-month-old animals. This defect correlated with the presence of numerous beta-amyloid deposits and hypertrophic astrocytes. In contrast, release was normal in cerebellum, a region devoid of beta-amyloid deposition and astrocytosis. The Ca2+-dependent process by which TNFalpha evokes glutamate release in acute slices is distinct from synaptic release and displays properties identical to those observed in cultured astrocytes, notably PG dependence. However, prostaglandin E2 induced normal glutamate release responses in 12-month-old PDAPP mice, suggesting that the pathology-associated defect involves the TNFalpha-dependent control of secretion rather than the secretory process itself. Reduced expression of DENN/MADD, a mediator of TNFalpha-PG coupling, might account for the defect. Alteration of this neuromodulatory astrocytic pathway is described here for the first time in relation to Alzheimer disease.
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Affiliation(s)
- Daniela Rossi
- Department of Pharmacological Sciences, Center of Excellence on Neurodegenerative Diseases, University of Milan, via Balzaretti, 9, 20133 Milan, Italy
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82
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Kahle PJ, Haass C. The emerging utility of animal models of chronic neurodegenerative diseases. Expert Opin Ther Targets 2005; 5:125-32. [PMID: 15992171 DOI: 10.1517/14728222.5.1.125] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The two most common neurodegenerative diseases are Alzheimer's disease (AD) and Parkinson's disease (PD). The symptoms are caused by the initially selective degeneration of neuronal subpopulations involved in memory (AD) or movement control (PD). The cause of both diseases is unknown, but ageing is an inevitable risk factor. The identification of disease-associated genes was a breakthrough for the understanding of molecular mechanisms of neurodegeneration and has provided the basis for the establishment of cell culture and animal model systems, instrumental for target validation and drug screening. Familial AD is caused by mutations in the beta-amyloid precursor protein (betaAPP) and in the gene products responsible for its proteolytic processing, namely the presenilins. Transgenic mice expressing these mutant genes develop characteristic AD plaques in an age-dependent manner. A reduction of plaque burden and amelioration of cognitive decline in these animals was recently achieved by vaccination with amyloid beta-protein fibrils. The other hallmark lesion of AD, the neurofibrillary tangle, has been modelled recently in transgenic mice expressing mutant tau protein linked to frontotemporal dementia. PD is characterised by intraneuronal cytoplasmic deposits (Lewy bodies) of the PD-associated gene product alpha-synuclein. Transgenic expression of alpha-synuclein recreated hallmark features of PD in mice and fruit flies, establishing alpha-synuclein as PD-causing drug target. Moreover, environmental risk factors such as the pesticide rotenone have been used successfully to generate rodent models of PD. Lesion models of PD are being exploited for the development of experimental gene therapy and transplantation approaches.
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Affiliation(s)
- P J Kahle
- Laboratory for Alzheimer's and Parkinson's Disease Research, Department of Biochemistry, Ludwig Maximilians University, Schillerstrasse 44, D-80336 Munich, Germany.
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83
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Kobayashi DT, Chen KS. Behavioral phenotypes of amyloid-based genetically modified mouse models of Alzheimer's disease. GENES BRAIN AND BEHAVIOR 2005; 4:173-96. [PMID: 15810905 DOI: 10.1111/j.1601-183x.2005.00124.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative affliction of the elderly, presenting with progressive memory loss and dementia and terminating with death. There have been significant advances in understanding the biology and subsequent diagnosis of AD; however, the furious pace of research has not yet translated into a disease-modifying treatment. While scientific inquiry in AD is largely centered on identifying biological players and pathological mechanisms, the day-to-day realities of AD patients and their caregivers revolve around their steady and heartbreaking cognitive decline. In the past decade, AD research has been fundamentally transformed by the development of genetically modified animal models of amyloid-driven neurodegeneration. These important in vivo models not only replicate some of the hallmark pathology of the disease, such as plaque-like amyloid accumulations and astrocytic inflammation, but also some of the cognitive impairments relevant to AD. In this article, we will provide a detailed review of the behavioral and cognitive deficits present in several transgenic mouse models of AD and discuss their functional changes in response to experimental treatments.
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Affiliation(s)
- D T Kobayashi
- Pharmacology Department, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
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84
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Zheng K, Kuteeva E, Xia S, Bartfai T, Hökfelt T, Xu ZQD. Age-related impairments of synaptic plasticity in the lateral perforant path input to the dentate gyrus of galanin overexpressing mice. Neuropeptides 2005; 39:259-67. [PMID: 15944020 DOI: 10.1016/j.npep.2005.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Accepted: 02/15/2005] [Indexed: 11/17/2022]
Abstract
In the present study, electrophysiological recordings were made from hippocampal slices obtained from mice overexpressing galanin under the promoter for the platelet-derived growth factor-B (GalOE mice). In these mice, a particularly strong galanin expression is seen in the granule cell layer/mossy fibers. Paired-pulse facilitation (PPF) of excitatory postsynaptic field potentials (fEPSPs) at the lateral perforant path (LPP)-dentate gyrus synapses was elicited in the dentate gyrus after stimulation with different interpulse intervals. Slices from young adult wild-type (WT) animals showed significant PPF of the 2nd EPSP evoked with paired-pulse stimuli, while PPF was reduced in slices from young adult GalOE mice, as well as aged WT mice, but were not observed at all in slices from aged GalOE animals. Application of the putative galanin antagonist M35 increased PPF in slices from aged WT mice as well as from adult and aged GalOE mice, but had no effect in slices taken from young adult WT mice. These data indicate that galanin is involved in hippocampal synaptic plasticity, in particular in age-related reduction of synaptic plasticity in the LPP input to the dentate gyrus. Galaninergic mechanisms may therefore represent therapeutic targets for treatment of age-related memory deficits and Alzheimer's disease.
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Affiliation(s)
- Kang Zheng
- Department of Neuroscience, Karolinska Institutet, S-171 71, Stockholm, Sweden
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85
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Savonenko A, Xu GM, Melnikova T, Morton JL, Gonzales V, Wong MPF, Price DL, Tang F, Markowska AL, Borchelt DR. Episodic-like memory deficits in the APPswe/PS1dE9 mouse model of Alzheimer's disease: relationships to beta-amyloid deposition and neurotransmitter abnormalities. Neurobiol Dis 2005; 18:602-17. [PMID: 15755686 DOI: 10.1016/j.nbd.2004.10.022] [Citation(s) in RCA: 297] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2003] [Revised: 10/18/2004] [Accepted: 10/21/2004] [Indexed: 10/25/2022] Open
Abstract
Transgenic mice made by crossing animals expressing mutant amyloid precursor protein (APPswe) to mutant presenilin 1 (PS1dE9) allow for incremental increases in Abeta42 production and provide a model of Alzheimer-type amyloidosis. Here, we examine cognition in 6- and 18-month old transgenic mice expressing APPswe and PS1dE9, alone and in combination. Spatial reference memory was assessed in a standard Morris Water Maze task followed by assessment of episodic-like memory in Repeated Reversal and Radial Water maze tasks. We then used factor analysis to relate changes in performance in these tasks with cholinergic markers, somatostatin levels, and amyloid burden. At 6 months of age, APPswe/PS1dE9 double-transgenic mice showed visible plaque deposition; however, all genotypes, including double-transgenic mice, were indistinguishable from nontransgenic animals in all cognitive measures. In the 18-month-old cohorts, amyloid burdens were much higher in APPswe/PS1dE9 mice with statistically significant but mild decreases in cholinergic markers (cortex and hippocampus) and somatostatin levels (cortex). APPswe/PS1dE9 mice performed all cognitive tasks less well than mice from all other genotypes. Factor and correlation analyses defined the strongest correlation as between deficits in episodic-like memory tasks and total Abeta loads in the brain. Collectively, we find that, in the APPswe/PS1dE9 mouse model, some form of Abeta associated with amyloid deposition can disrupt cognitive circuits when the cholinergic and somatostatinergic systems remain relatively intact; and that episodic-like memory seems to be more sensitive to the toxic effects of Abeta.
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Affiliation(s)
- Alena Savonenko
- Department of Pathology, Johns Hopkins School of Medicine, Ross Building, Room 558, 720 Rutland Avenue, Baltimore, MD 21205, USA.
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86
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Hyde LA, Kazdoba TM, Grilli M, Lozza G, Brusa R, Brussa R, Zhang Q, Wong GT, McCool MF, Zhang L, Parker EM, Higgins GA. Age-progressing cognitive impairments and neuropathology in transgenic CRND8 mice. Behav Brain Res 2005; 160:344-55. [PMID: 15863231 DOI: 10.1016/j.bbr.2004.12.017] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Revised: 12/21/2004] [Accepted: 12/21/2004] [Indexed: 12/12/2022]
Abstract
Patients with Alzheimer's disease suffer from progressive cognitive impairments and show distinct post-mortem neuropathology, including beta-amyloid plaques. Transgenic (Tg) CRND8 mice carry a mutated human amyloid precursor protein gene and show age-related increases in beta-amyloid production and plaque deposition. It was previously reported that during the early stages of plaque deposition, Tg CRND8 mice demonstrated Morris maze impairments. However, it is unknown if Tg mice would be impaired at an earlier age prior to plaque deposition or more impaired at a later age with more extensive plaque deposition. In the current study, we describe Tg CRND8 age-progressing beta-amyloid neuropathology and cognitive abilities in greater detail. At all ages, Tg mice showed normal short-term memory in the Y-maze. Pre-plaque Tg and age-matched Non-Tg mice did not differ in learning the spatial Morris water maze. However, both early and late plaque Tg mice showed impairments during acquisition. In addition, although early plaque Tg mice performed well in the probe trial, late plaque Tg mice demonstrated impaired probe trial performance. Therefore compared to their Non-Tg littermates, Tg CRND8 mice demonstrate cognitive impairments that progressed with age and seemed to coincide with the onset of beta-amyloid plaque deposition.
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Affiliation(s)
- Lynn A Hyde
- Schering-Plough Research Institute, NJ 07033, Kenilworth, USA.
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87
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Lambourne SL, Sellers LA, Bush TG, Choudhury SK, Emson PC, Suh YH, Wilkinson LS. Increased tau phosphorylation on mitogen-activated protein kinase consensus sites and cognitive decline in transgenic models for Alzheimer's disease and FTDP-17: evidence for distinct molecular processes underlying tau abnormalities. Mol Cell Biol 2005; 25:278-93. [PMID: 15601849 PMCID: PMC538769 DOI: 10.1128/mcb.25.1.278-293.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Revised: 06/21/2004] [Accepted: 09/06/2004] [Indexed: 11/20/2022] Open
Abstract
Abnormal tau phosphorylation occurs in several neurodegenerative disorders, including Alzheimer's disease (AD) and frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17). Here, we compare mechanisms of tau phosphorylation in mouse models of FTDP-17 and AD. Mice expressing a mutated form of human tau associated with FTDP-17 (tau(V337M)) showed age-related increases in exogenous tau phosphorylation in the absence of increased activation status of a number of kinases known to phosphorylate tau in vitro. In a "combined" model, expressing both tau(V337M) and the familial amyloid precursor protein AD mutation APP(V717I) in a CT100 fragment, age-dependent tau phosphorylation occurred at the same sites and was significantly augmented compared to "single" tau(V337M) mice. These effects were concomitant with increased activation status of mitogen-activated protein kinase (MAPK) family members (extracellular regulated kinases 1 and 2, p38, and c-Jun NH(2)-terminal kinase) but not glycogen synthase kinase-3alphabeta or cyclin-dependent kinase 5. The increase in MAPK activation was a discrete effect of APP(V717I)-CT100 transgene expression as near identical changes were observed in single APP(V717I)-CT100 mice. Age-dependent deficits in memory were also associated with tau(V337M) and APP(V717I)-CT100 expression. The data reveal distinct routes to abnormal tau phosphorylation in models of AD and FTDP-17 and suggest that in AD, tau irregularities may be linked to processing of APP C-terminal fragments via specific effects on MAPK activation status.
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Affiliation(s)
- Sarah L Lambourne
- Neurobiology Programme, The Babraham Institute, Babraham, Cambridge CB2 4AT, United Kingdom
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88
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Dumont M, Strazielle C, Staufenbiel M, Lalonde R. Spatial learning and exploration of environmental stimuli in 24-month-old female APP23 transgenic mice with the Swedish mutation. Brain Res 2004; 1024:113-21. [PMID: 15451372 DOI: 10.1016/j.brainres.2004.07.052] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2004] [Indexed: 10/26/2022]
Abstract
Transgenic mice overexpressing the betaAPP gene with the Swedish mutation under the control of the murine thy1 promoter show Alzheimer-like characteristics such as Abeta plaques in cerebral cortex and vessel walls. By comparison to age-matched non-transgenic controls, 2-year-old female APP23 transgenic mice crossed more segments in the open-field and had a higher number of fast ambulatory and stereotyped movements in a photocell activity chamber. In addition, APP23 mice entered more often and spent more time in the open arms of the elevated plus-maze. The acquisition of place learning in the Morris water maze was impaired in APP23 transgenic mice, but not in probe and visible platform subtasks. These results indicate that hyperactivity and impaired learning abilities characterize this mouse model of Alzheimer's disease and cerebral angiopathy.
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Affiliation(s)
- M Dumont
- Université de Rouen, INSERM U614, IFRMP23, Faculté de Médecine et de Pharmacie, 22 bld Gambetta, Bâtiment de Recherche, Salle 1D18, 76183 Rouen Cedex, France
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89
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Winsky-Sommerer R, Spier AD, Fabre V, de Lecea L, Criado JR. Overexpression of the human β-amyloid precursor protein downregulates cortistatin mRNA in PDAPP mice. Brain Res 2004; 1023:157-62. [PMID: 15364032 DOI: 10.1016/j.brainres.2004.04.082] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2004] [Indexed: 11/29/2022]
Abstract
We measured preprocortistatin mRNA expression in young and aged transgenic (Tg) mice overexpressing the human beta-amyloid precursor protein (hbetaAPP) under the platelet-derived growth factor-beta promoter. Our findings suggest that the significant increase in hippocampal cortistatin mRNA expression during normal aging is significantly attenuated in Tg mice at an age known to exhibit beta-amyloid protein (Abeta) deposition. These deficits in cortistatin expression may play a role in the deficits in hippocampal-dependent spatial learning and sleep/wake states previously demonstrated in aged Tg mice.
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90
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Leighty RE, Nilsson LNG, Potter H, Costa DA, Low MA, Bales KR, Paul SM, Arendash GW. Use of multimetric statistical analysis to characterize and discriminate between the performance of four Alzheimer's transgenic mouse lines differing in Abeta deposition. Behav Brain Res 2004; 153:107-21. [PMID: 15219712 DOI: 10.1016/j.bbr.2003.11.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2003] [Revised: 11/14/2003] [Accepted: 11/14/2003] [Indexed: 11/20/2022]
Abstract
Behavioral assessment of genetically-manipulated mouse lines for Alzheimer's disease has become an important index for determining the efficacy of therapeutic interventions and examining disease pathogenesis. However, the potential for higher level statistical analyses to assist in these goals remains largely unexplored. The present study thus involved multimetric statistical analyses of behavioral and beta-amyloid (Abeta) deposition measures from four PDAPP-derived transgenic mouse lines that differ in extent of Abeta deposition. For all four lines, multiple behavioral measures obtained from a comprehensive task battery administered at 15-16 months of age were collectively examined by correlation, factor, and discriminant function analyses. In addition, both compact and total beta-amyloid (Abeta) histologic measures were determined from the same animals. Widespread intra- and inter-task correlations were evident, with impairment in all three water tasks (Morris maze, platform recognition, and radial arm water maze) correlating extensively with Abeta deposition in hippocampus and cerebral cortex. By elucidating the underlying relationships among measures, factor analysis revealed a single primary factor (Factor 1) that loaded most cognitive measures, particularly those for working memory and recognition. Abeta deposition measures loaded exclusively on this primary factor. In individual animals, only factor scores derived from this primary factor were correlated with Abeta deposition. Both of these findings again underscore the association between cognitive impairment and Abeta deposition. Finally, discriminant function analysis (step-wise forward method) was able to distinguish between all four AD transgenic lines based on behavioral performance alone, as well as when Abeta deposition measures were included. Our results demonstrate the utility of higher level, multimetric analysis of behavioral measures from AD transgenic mice. Analyses such as these will be very beneficial for the functional evaluation of therapeutic interventions against AD and for finding behavioral measures that can serve as predictors of pathology.
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Affiliation(s)
- Ralph E Leighty
- Memory and Aging Research Laboratory, SCA 110, University of South Florida, Tampa, FL 33620, USA
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91
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Dudal S, Krzywkowski P, Paquette J, Morissette C, Lacombe D, Tremblay P, Gervais F. Inflammation occurs early during the Abeta deposition process in TgCRND8 mice. Neurobiol Aging 2004; 25:861-71. [PMID: 15212840 DOI: 10.1016/j.neurobiolaging.2003.08.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2002] [Revised: 06/25/2003] [Accepted: 08/28/2003] [Indexed: 11/17/2022]
Abstract
Alzheimer's disease (AD) is characterized by a progressive cognitive decline leading to dementia and involves the deposition of amyloid-beta (Abeta) peptides into senile plaques. Other neuropathological features that accompany progression of the disease include a decrease in synaptic density, neurofibrillary tangles, dystrophic neurites, inflammation, and neuronal cell loss. In this study, we report the early kinetics of brain amyloid deposition and its associated inflammation in an early onset transgenic mouse model of AD (TgCRND8) harboring the human amyloid precursor protein gene with the Indiana and Swedish mutations. Both diffuse and compact plaques were detected as early as 9-10 weeks of age. Abeta-immunoreactive (Abeta-IR) plaques (4G8-positive) appeared first in the neocortex and amygdala, then in the hippocampal formation, and lastly in the thalamus. Compact plaques (ThioS-positive) with an amyloid core were observed as early as diffuse plaques were detected, but in lower numbers. Amyloid deposition increased progressively with age. The formation of plaques was concurrent with the appearance of activated microglial cells and shortly followed by the clustering of activated astrocytes around plaques at 13-14 weeks of age. This TgCRND8 mouse model allows for a rapid, time-dependent study of the relationship between the fibrillogenic process and the inflammatory response during the brain amyloidogenic process.
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Affiliation(s)
- Sherri Dudal
- Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Qué., Canada
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92
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Howlett DR, Richardson JC, Austin A, Parsons AA, Bate ST, Davies DC, Gonzalez MI. Cognitive correlates of Aβ deposition in male and female mice bearing amyloid precursor protein and presenilin-1 mutant transgenes. Brain Res 2004; 1017:130-6. [PMID: 15261108 DOI: 10.1016/j.brainres.2004.05.029] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2004] [Indexed: 10/26/2022]
Abstract
Several transgenic mouse models of Alzheimer's disease (AD) have been developed that exhibit beta-amyloid (Abeta) neuropathology and behavioural deficits. However, not all studies have investigated the relationship between the development of cognitive impairment and neuropathology. Therefore, temporal changes in cognition were investigated in male and female double-mutant APPswexPS1.M146V (TASTPM) transgenic mice using an object recognition test and correlated with the development of cerebral Abeta neuropathology. Both male and female TASTPM mice exhibited similar significant cognitive impairment at 6, 8 and 10 months of age in the object recognition test, compared to wild-type littermates. There was no such cognitive impairment at 3 or 4 months of age. Quantitative immunohistochemistry using a battery of Abeta antibodies demonstrated that cerebral Abeta deposition was first apparent in 3-month-old mice, and it increased with age. The early appearance of cerebral Abeta deposits in the double-transgenic TASTPM mice supports the evidence that mutations in the PS1 gene accelerate Abeta deposition. The cerebral Abeta load was greater in female than in male TASTPM mice at all ages investigated. In the electron microscope, mature Abeta plaques comprising a fibrillar core surrounded by degenerating neurites and reactive glia were first observed in the cortex of TASTPM mice at 6 months of age, the same age at which cognitive impairment became apparent. These results suggest that the cognitive impairment in TASTPM mice is related to the disruption of neural connectivity and not simply Abeta deposition, which first occurs 3 months earlier.
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Affiliation(s)
- David R Howlett
- Neurology and GI CEDD, GlaxoSmithKline Research and Development Limited, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW, UK.
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93
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Sadowski M, Pankiewicz J, Scholtzova H, Ji Y, Quartermain D, Jensen CH, Duff K, Nixon RA, Gruen RJ, Wisniewski T. Amyloid-beta deposition is associated with decreased hippocampal glucose metabolism and spatial memory impairment in APP/PS1 mice. J Neuropathol Exp Neurol 2004; 63:418-28. [PMID: 15198121 DOI: 10.1093/jnen/63.5.418] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In Alzheimer disease (AD) patients, early memory dysfunction is associated with glucose hypometabolism and neuronal loss in the hippocampus. Double transgenic (Tg) mice co-expressing the M146L presenilin 1 (PS1) and K670N/M671L, the double "Swedish" amyloid precursor protein (APP) mutations, are a model of AD amyloid-beta deposition (Abeta) that exhibits earlier and more profound impairments of working memory and learning than single APP mutant mice. In this study we compared performance on spatial memory tests, regional glucose metabolism, Abeta deposition, and neuronal loss in APP/PS1, PS1, and non-Tg (nTg) mice. At the age of 2 months no significant morphological and metabolic differences were detected between 3 studied genotypes. By 8 months, however, APP/PS1 mice developed selective impairment of spatial memory, which was significantly worse at 22 months and was accompanied by reduced glucose utilization in the hippocampus and a 35.8% dropout of neurons in the CA1 region. PS1 mice exhibited a similar degree of neuronal loss in CA1 but minimal memory deficit and no impairment of glucose utilization compared to nTg mice. Deficits in 22 month APP/PS1 mice were accompanied by a substantially elevated Abeta load, which rose from 2.5% +/- 0.4% at 8 months to 17.4% +/- 4.6%. These findings implicate Abeta or APP in the behavioral and metabolic impairments in APP/PS1 mice and the failure to compensate functionally for PS1-related hippocampal cell loss.
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Affiliation(s)
- Marcin Sadowski
- Department of Neurology, New York University School of Medicine, New York, New York 10016, USA
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94
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Pennanen L, Welzl H, D'Adamo P, Nitsch RM, Götz J. Accelerated extinction of conditioned taste aversion in P301L tau transgenic mice. Neurobiol Dis 2004; 15:500-9. [PMID: 15056457 DOI: 10.1016/j.nbd.2003.11.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2003] [Revised: 09/29/2003] [Accepted: 11/18/2003] [Indexed: 01/01/2023] Open
Abstract
Neurofibrillary tangles, insoluble protein deposits composed of filamentous tau aggregates, are neuropathological hallmarks of Alzheimer's disease and familial frontotemporal dementia (FTDP-17). Transgenic mice expressing the FTDP-17 mutation P301L of tau recapitulate key features of the human pathology, that is, tau proteins aggregate and neurofibrillary tangles begin to appear in the amygdala at 6 months of age. To detect early signs of tau aggregate-associated changes, we investigated behavioral alterations and cognitive deficits in such mice using an amygdala-specific test battery for anxiety-related and cognitive behavior. P301L mice had anxiety levels not different from wild-types, but their exploratory behavior was significantly increased. Acquisition of a fear response to tone and context as well as taste aversion was comparable to wild-types. However, extinction of a conditioned taste aversion was significantly accelerated. We conclude that already aggregation of tau proteins not yet accompanied by massive formation of neurofibrillary tangles causes selective behavioral deficits.
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Affiliation(s)
- Luis Pennanen
- Division of Psychiatry Research, University of Zürich, 8008 Zürich, Switzerland
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95
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Trinchese F, Liu S, Battaglia F, Walter S, Mathews PM, Arancio O. Progressive age-related development of Alzheimer-like pathology in APP/PS1 mice. Ann Neurol 2004; 55:801-14. [PMID: 15174014 DOI: 10.1002/ana.20101] [Citation(s) in RCA: 272] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Increasing evidence points to synaptic plasticity impairment as one of the first events in Alzheimer's disease (AD). However, studies on synaptic dysfunction in different transgenic AD models that overexpress familial AD mutant forms of amyloid precursor protein (APP) and/or presenilin (PS) have provided conflicting results. Both long-term potentiation (LTP) and basal synaptic transmission (BST) have been found to be both unchanged and altered in different models and under differing experimental conditions. Because of their more robust amyloid-beta (Abeta) deposition, double transgenic mice currently are used by several laboratories as an AD model. Here, we report that mice overexpressing APP (K670N:M671L) together with PS1 (M146L) have abnormal LTP as early as 3 months of age. Interestingly, reduced LTP paralleled plaque appearance and increased Abeta levels and abnormal short-term memory (working memory). BST and long-term memory (reference memory) are impaired only later (approximately 6 months) as amyloid burden increases. Abeta pathology across different ages did not correlate with synaptic and cognitive deficits, suggesting that Abeta levels are not a marker of memory decline. In contrast, progression of LTP impairment correlated with the deterioration of working memory, suggesting that percentage of potentiation might be an indicator of the cognitive decline and disease progression in the APP/PS1 mice.
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Affiliation(s)
- Fabrizio Trinchese
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA
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96
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Phinney AL, Horne P, Yang J, Janus C, Bergeron C, Westaway D. Mouse models of Alzheimer's disease: the long and filamentous road. Neurol Res 2003; 25:590-600. [PMID: 14503012 DOI: 10.1179/016164103101202020] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Alzheimer's disease (AD) is characterized by memory impairment leading to dementia, deposition of amyloid plaques and neurofibrillary tangles (NFTs), and neuronal loss. The major component of plaques is the amyloid beta peptide, A beta, whereas NFTs contain hyperphosphorylated forms of the microtubule-associated protein tau (tau). Familial AD (FAD) mutations either elevate A beta synthesis by favoring 'secretase' of the Alzheimer beta-amyloid precursor protein (APP) or enhance the fibrillogenic properties of this peptide. Mutations in the tau gene cause a different disease denoted FTPD-17, but suggest that the aberrant forms of tau seen in AD are unlikely to be benign. These findings imply a complex pathogenic cascade in AD and important goals of transgenic modeling are to capture and stratify this pathogenic process. Several laboratories have created APP transgenic (Tg) mice that exhibit AD-like amyloid pathology and A beta burdens. These Tg lines also exhibit deficits in spatial reference and/or working memory, with immunization against A beta attenuating both AD-associated phenotypes. Tangle-like pathologies are observed in mice expressing FTPD-17 mutant forms of tau, but florid tau pathologies based upon the wild type (wt) tau isoforms present in AD have proven more elusive. Creation of animal models with robust amyloid and tau pathologies, yet free of irrelevant confounding pathologies, remains a major objective in this field.
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Affiliation(s)
- Amie L Phinney
- Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
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97
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Palop JJ, Jones B, Kekonius L, Chin J, Yu GQ, Raber J, Masliah E, Mucke L. Neuronal depletion of calcium-dependent proteins in the dentate gyrus is tightly linked to Alzheimer's disease-related cognitive deficits. Proc Natl Acad Sci U S A 2003; 100:9572-7. [PMID: 12881482 PMCID: PMC170959 DOI: 10.1073/pnas.1133381100] [Citation(s) in RCA: 311] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Transgenic mice expressing human amyloid precursor proteins (hAPP) and amyloid-beta peptides (Abeta) in neurons develop phenotypic alterations resembling Alzheimer's disease (AD). The mechanisms underlying cognitive deficits in AD and hAPP mice are largely unknown. We have identified two molecular alterations that accurately reflect AD-related cognitive impairments. Learning deficits in mice expressing familial AD-mutant hAPP correlated strongly with decreased levels of the calcium-binding protein calbindin-D28k (CB) and the calcium-dependent immediate early gene product c-Fos in granule cells of the dentate gyrus, a brain region critically involved in learning and memory. These molecular alterations were age-dependent and correlated with the relative abundance of Abeta1-42 but not with the amount of Abeta deposited in amyloid plaques. CB reductions in the dentate gyrus primarily reflected a decrease in neuronal CB levels rather than a loss of CB-producing neurons. CB levels were also markedly reduced in granule cells of humans with AD, even though these neurons are relatively resistant to AD-related cell death. Thus, neuronal populations resisting cell death in AD and hAPP mice can still be drastically altered at the molecular level. The tight link between Abeta-induced cognitive deficits and neuronal depletion of CB and c-Fos suggests an involvement of calcium-dependent pathways in AD-related cognitive decline and could facilitate the preclinical evaluation of novel AD treatments.
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Affiliation(s)
- Jorge J Palop
- Gladstone Institute of Neurological Disease and Department of Neurology, University of California, San Francisco, CA 94141, USA
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98
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Sant'Angelo A, Trinchese F, Arancio O. Usefulness of behavioral and electrophysiological studies in transgenic models of Alzheimer's disease. Neurochem Res 2003; 28:1009-15. [PMID: 12737525 DOI: 10.1023/a:1023251005197] [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: 11/12/2022]
Abstract
Over the past several years researchers have engineered many transgenic models of Alzheimer's disease. Since loss of memory is one of the major hallmarks of the disorder, the phenotypic characterization of these animals has included both behavioral tests which aim to evaluate learning abilities, and electrophysiological studies to analyze synaptic transmission and long-term potentiation, a widely studied cellular model of learning and memory. These studies are fundamental for the design of novel therapies for the treatment and/or prevention of Alzheimer's disease.
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Affiliation(s)
- Antonino Sant'Angelo
- Department of Psychiatry, New York University School of Medicine, New York, New York 10016, USA
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99
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Beck M, Bigl V, Rossner S. Guinea pigs as a nontransgenic model for APP processing in vitro and in vivo. Neurochem Res 2003; 28:637-44. [PMID: 12675155 DOI: 10.1023/a:1022850113083] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Alzheimer's disease (AD) is characterized, amongst others, by the appearance of vascular and parenchymal beta-amyloid deposits in brain. Such aggregates are mainly composed of beta-amyloid peptides, which are derived by proteolytic processing of a larger amyloid precursor protein (APP). APP is highly conserved among mammalian species, but experimental studies in rodents are often hampered by the humble APP-processing in the amyloidogenic pathway and by the inability of rodent beta-amyloid peptides to form higher molecular aggregates such as soluble oligomers and insoluble beta-amyloid plaques. Thus, there is need for in vitro and in vivo model systems that allow identification of factors that increase amyloidogenic APP processing and accelerate beta-amyloid plaque formation and testing the potency of pharmacological manipulations to ameliorate beta-amyloid load in brain. Transgenic mice that overexpress human APP containing AD-associated mutations that favor the amyloidogenic pathway of APP processing represent such a model. However, mutations of the APP gene are not frequent in AD and, therefore, the mechanisms of beta-amyloid plaque formation, the composition of beta-amyloid plaques, and the accompanying tissue response in brain of these animals may be different from that in AD. In contrast, guinea pigs express beta-amyloid peptides of the human sequence and appear to represent a more physiological model to examine the long-term effects of experimental manipulations on APP processing and beta-amyloid plaque formation in vivo. Additionally, APP processing in guinea pig primary neuronal cultures has been shown to be similar to cultures of human origin. In this article we highlight the advantages and limitations of using guinea pigs as experimental models to study APP processing.
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Affiliation(s)
- Mike Beck
- Paul Flechsig Institute for Brain Research, Department of Neurochemistry, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
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100
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Savonenko AV, Xu GM, Price DL, Borchelt DR, Markowska AL. Normal cognitive behavior in two distinct congenic lines of transgenic mice hyperexpressing mutant APP SWE. Neurobiol Dis 2003; 12:194-211. [PMID: 12742740 DOI: 10.1016/s0969-9961(02)00012-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Amyloid deposition appears to be an early and crucial event in Alzheimer's disease (AD). To generate animal models of AD, mice expressing full-length amyloid precursor protein (APP), with mutations linked to FAD, have been created. These animals exhibit abnormalities characteristic of AD, including deposits of beta-amyloid (Abeta), neuritic plaques, and glial responses. In studies of cognition in these animals, there have been several reports of memory disturbances well before the appearance of amyloid deposits. We have developed two distinct lines of transgenic mice (C3-3 and E1-2) that express the "Swedish" variant of APP (APP(SWE)) at levels that are approximately three-fold higher than endogenous mouse APP. Both lines have been backcrossed to C57BL/6J mice for 10 generations. Here, we use longitudinal and cross-sectional studies to evaluate the cognitive performance of our animals, where the concentration of Abeta1-42 in brain increases with aging from low levels (2-10 pmol/g) at 6-14 months of age to relatively high levels (60-100 pmol/g) at 24-26 months, when deposits of Abeta were beginning to form. When 12-month-old mice were tested in tasks that assess reference and working memory, transgenic mice from both lines could not be distinguished from nontransgenic littermates. Further study of 24- to 26-month-old transgenic mice (C3-3 line) found no evidence of memory impairment despite the presence of high levels of human Abeta (60-100 pmol/g). Thus, the expression of APP(SWE) at approximately three-fold over endogenous levels, which is sufficient to induce amyloid deposition at advanced ages, does not significantly erode cognitive performance in aged mice.
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Affiliation(s)
- Alena V Savonenko
- Department of Psychology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
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