Research Models

5xFAD (B6SJL)

Synonyms: 5XFAD, APP/PS1, Tg6799, Tg-5xFAD

Species: Mouse
Genes: APP, PSEN1
Mutations: APP KM670/671NL (Swedish), APP I716V (Florida), APP V717I (London), PSEN1 M146L (A>C), PSEN1 L286V
Modification: APP: Transgenic; PSEN1: Transgenic
Disease Relevance: Alzheimer's Disease
Strain Name: B6SJL-Tg(APPSwFlLon,PSEN1*M146L*L286V)6799Vas/Mmjax
Genetic Background: C57BL/6 x SJL
Availability: The Jackson Lab; available through the JAX MMRRC Stock# 034840; Live

Summary

5xFAD mice express human APP and PSEN1 transgenes with a total of five AD-linked mutations: the Swedish (K670N/M671L), Florida (I716V), and London (V717I) mutations in APP, and the M146L and L286V mutations in PSEN1. Three lines were generated originally: Tg6799, Tg7031, and Tg7092. The Tg6799 line, which expresses the highest levels of mutant APP, is the most studied of the three, and is described here on the original hybrid B6SJL background. Tg6799 mice are also available on a congenic C57BL6 background, described elsewhere.

These widely used mice recapitulate many AD-related phenotypes and have a relatively early and aggressive presentation. Amyloid plaques, accompanied by gliosis, are seen in mice as young as two months of age. Amyloid pathology is more severe in females than in males. Neuron loss occurs in multiple brain regions, beginning at about 6 months in the areas with the most pronounced amyloidosis. Mice display a range of cognitive and motor deficits.

The descriptions on this page refer to mice hemizygous for the APP and PSEN1 transgenes.

Levels of human APP in whole brain have been reported as between half (Sadleir et al., 2018) and three times (Ohno et al., 2006) that of endogenous mouse APP, and levels of transgenic PS1 as half those of the endogenous protein (Sadleir et al., 2018). Females express somewhat more APP than males, probably due to an estrogen response element in the Thy1 promoter used to drive transgene expression (Sadleir et al., 2015; Sadleir et al., 2018), and generate higher levels of Aβ (Oakley et al., 2006; Maarouf et al., 2013). Soluble Aβ42 is detectable by 1.5 months and its levels increase steeply with age. Aβ40 levels also increase with age, but rise more slowly and are substantially lower than for Aβ42, with the Aβ42:Aβ40 ratio reaching as high as 25 in young animals (Oakley et al., 2006). An age-dependent increase in BACE1 has also been reported (Devi and Ohno, 2010; Maarouf et al., 2013).

Neuropathology

The 5xFAD model rapidly develops severe amyloid pathology. These mice accumulate high levels of intraneuronal Aβ42, beginning around 1.5 months of age (Oakley et al., 2006). Intracellular immunoreactivity for Aβ was observed to co-localize with that for cathepsin-D, a maker of lysosomes and other acidic organelles (Youmans et al., 2012). Staining with thioflavin S suggests that intracellular Aβ42 may form β-pleated sheet aggregates (Oakley et al., 2006).

Extracellular amyloid deposition begins around 2 months, first in the subiculum and layer V of the cortex, and increasing rapidly with age. Plaques are found throughout the hippocampus and cortex by six months; in older mice, plaques are present in the thalamus, brainstem, and olfactory bulb, but are absent from the cerebellum (Oakley et al., 2006). Amyloid pathology has also been observed in the spinal cord, appearing at 11 weeks in cervical and lumbar regions and extending along the length of the cord by 19 weeks (Chu et al., 2017). Females exhibit more aggressive plaque pathology: plaque numbers in the hippocampus and cortex are higher in females than in males, and continue to increase until at least 14 months of age, while numbers in males plateau at 10 months (Bhattacharya et al., 2014).

Astrogliosis and microgliosis begin around two months, developing in parallel with plaque deposition (Oakley et al., 2006).

Synaptic degeneration, assessed as whole-brain levels of the presynaptic marker synaptophysin, begins by four months of age; levels of syntaxin, another presynaptic marker, and PSD-95, a postsynaptic marker, decline by 9 months (Oakley et al., 2006). Little information is available about the spatiotemporal pattern or details of synapse loss. In an ultrastructural study of synapses in the hippocampi of 12-month mice, an almost 50 percent loss of axospinous synapses was found in stratum lacunosum-moleculare, while synapse numbers in the stratum radiatum of 5xFAD mice did not differ from non-transgenic controls (Neuman et. al., 2015).

Neuron loss has been observed in multiple brain regions in this model. In the areas with the most severe amyloidosis—the subiculum and cortical layer V—neuron loss begins at about 6 months of age (Oakley et al., 2006; Eimer and Vassar, 2013). A reduction in the number of cholinergic neurons in the basal forebrain has also been observed at 6 months (Devi and Ohno, 2010). Thirty percent fewer parvalbumin-positive inhibitory interneurons were found in the barrel fields of 12-month 5xFAD mice, compared with non-transgenic mice (Flanigan et al., 2014). Whether spinal neurons are lost is uncertain: one study found no neuron loss in the cervical cord of 6-month 5xFAD mice, compared with non-transgenic littermates (Chu et al., 2017), while a second study reported a reduction in neuron density in the ventral horn of 12-month mice (Li et al., 2013). However, in addition to studying older animals, the latter study compared 5xFAD mice on a hybrid B6SJL background with wild-type C57BL6 mice.

The noradrenergic system may also be compromised in this model: Hypertrophic neurons and astrogliosis have been observed in the locus coeruleus of 4.5 month-old mice (Kalinin et al., 2012).

Myelin abnormalities have been reported in mice approximately 6 months of age (Chu et al., 2017).

A neuroanatomical tract tracing study in mice approximately a year old found reduced inputs to the hippocampus from multiple brain areas, including the olfactory bulb, medial septal area, entorhinal cortex, substantia nigra, dorsal raphe nucleus, and locus coeruleus (Jeon et al., 2018).

Tangles are not typical in this model (Oakley et al., 2006).

Electrophysiology

Basal synaptic transmission and LTP in hippocampal area CA1 begin to deteriorate between 4 and 6 months, but paired pulse facilitation remains normal at least until 6 months (Kimura and Ohno, 2009; Crouzin et al., 2013). Deficits in basal synaptic transmission were also observed in layer V of somatosensory cortex of 6-month 5xFAD mice (Crouzin et al., 2013). The amplitude and frequency of spontaneous excitatory postsynaptic currents in the hippocampal stratum radiatum do not differ between transgenic and wild-type mice, at approximately one month and 11 to 15 months (Neuman et al., 2015).

Electrographic seizures were recorded in a small group of aged (18-month) 5xFAD mice (Siwek et al., 2015).

Behavior

Spontaneous alternation in the Y-maze, a measure of spatial working memory, is impaired beginning at approximately 4 to 5 months of age (Oakley et al., 2006; Devi and Ohno, 2010).

Impaired spatial memory in the Morris water maze was reported in 6-month mice (Xiao et al., 2015), while impaired learning was evident in mice tested at 9 months (Flanigan et al., 2014) and approximately one year of age (O’Leary et al., 2018).

When assessed using a contextual-fear-conditioning test, memory function began to deteriorate between 4 and 5 months (Kimura and Ohno, 2009). During training, mice were placed in a novel environment, where they received a footshock. To test their memory of this event, mice were returned to the environment in which they had received the shock, and the amount of time the animals spent freezing (i.e., were immobilized with fear) was recorded. Tests administered one and 30 days after training are believed to assess hippocampus- and cortex- dependent processes, respectively. When tested one day after training, 4-month 5xFAD mice behaved similarly to non-transgenic littermates; however, in tests administered 30 days after training, 5xFAD mice spent less time freezing than did controls. These results suggest that 4-month 5xFAD mice have normal hippocampal-dependent short-term memory function, but that cortex-dependent remote memory stabilization is impaired during the one-month interval between training and testing. Six-month-old 5xFAD mice displayed memory deficits in both the 24-hour and 30-day tests.

Olfactory-guided behaviors were found to be normal at 3 months, but impaired at 6 months (Xiao et al., 2015).

Nine- to 12-month transgenic mice exhibited aberrant social behavior, engaging in more sniffing, following, mounting, and tail-pulling of cagemates, and showed impaired social recognition (Flanigan et al., 2014).

There are conflicting reports as to whether 5xFAD mice are hyperactive or differ from non-transgenic mice with regard to measures of anxiety (Flanigan et al., 2014; O’Leary et al., 2018).

5xFAD mice develop motor impairments, beginning at about 9 months of age (O’Leary et al., 2018; O’Leary et al., 2018). On the Rotarod, transgenic mice fall off more quickly than controls, and improve little across trials. 5xFAD mice also fall more quickly when tested on a balance beam, and in wire- and grid-suspension tests. In a tail-suspension test, 5xFAD mice have higher frequencies and durations of hind-limb clasping than do wild-type controls. Transgenic mice are also slower to complete a righting response and have shorter mean stride lengths than wild-type mice. Decreased grip strength is apparent by 16 months. Generally, age-related motor dysfunction progresses similarly in males and females.

Hearing impairments have been reported in 14- to 16-month-old mice. 5xFAD mice also show a reduced acoustic startle response, but this abnormality is apparent as early as 3 to 4 months, long before there is evidence of hearing loss (O’Leary et al., 2017).

Biomarkers

18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) revealed decreased glucose uptake in the olfactory bulbs of mice as young as 3 months of age (Xiao et al., 2015). Hypometabolism became apparent in multiple additional brain regions at 6 to 13 months: amygdala, basal forebrain, basal ganglia, cerebellum, hippocampus, hypothalamus, neocortex, and thalamus (MacDonald et al., 2014; Xiao et al., 2015).

A 10 percent decrease in hippocampal volume was observed in 13-month mice, using magnetic resonance imaging (MRI) (MacDonald et al., 2014).

In a pilot study of structural and functional connectivity, assessed using diffusion tensor imaging and resting state functional MRI, respectively, connectome organization was found to differ between 6-month 5xFAD and non-transgenic mice. However, in this small study with anesthetized animals, specific regional connectome differences—analogous to disrupted default mode network connectivity seen in AD patients, for example—were not found (Kesler et al., 2018).

Omics

Transcriptomic and proteomic analyses are being applied to compare 5xFAD and non-transgenic mice across the lifespan. In the hippocampus and cortex, the most pronounced differences to have emerged thus far involve genes related to neuroinflammation; differential expression is apparent by 4 months (Landel et al., 2014) and persists until at least 18 months (Siwek et al., 2015).

Single-cell RNAseq analysis identified a class of microglia (disease-associated microglia, or DAM) characterized by changes in expression of genes related to lysosomal/phagocytic pathways, endocytosis, and immune regulation; upregulated genes include Apoe, Ctsd, Lpl, Tyrobp, and Trem2, while downregulated genes include the “homeostatic genes” Cx3cr1, Tmem119, and P2ry12/P2ry13 (Keren-Shaul et al., 2017). The transition to a full DAM transcriptome profile is a multistep process, occurring between 3 and 8 months. 5xFAD females tend to have more DAM cells than age-matched males.

Proteomic analysis revealed differences between the brains of 5xFAD mice and non-transgenic littermates as young as one day of age (Mazi et al., 2018). Differentially expressed proteins are found in pathways related to Ephrin B signaling, clathrin-mediated endocytosis, integrin signaling, netrin signaling, and Rho GTPase signaling, among others.

A mass spectrometric study of crude synaptosomes prepared from the hippocampi of 4-month animals found 97 proteins that were differentially expressed in 5xFAD and wild-type mice (Hong et al., 2013). Among the most highly upregulated proteins were ApoE, ApoJ, GFAP, and nicastrin. Downregulated proteins included Shroom2, centaurin alpha 1, opioid-binding protein/cell adhesion molecule, microtubule associated protein RP/EB family member 2, and CB1 cannabinoid receptor-interacting protein 1. Gene Ontology analysis associated the differentially expressed proteins with the following biological processes: oxidative stress, ion homeostasis, protein folding, nerve impulse transmission, and axon ensheathment.

Other

No evidence of endoplasmic reticulum stress was found in mice 4 to 9 months of age (Sadleir et al., 2018).

This model was previously available at The Jackson Lab as Stock# 006554.

Modification Details

These transgenic mice were made by co-injecting two vectors encoding APP (with Swedish [K670N/M671L], Florida [I716V], and London [V717I] mutations) and PSEN1 (with M146L and L286V mutations), each driven by the mouse Thy1 promoter. The transgenes inserted at a single locus, Chr3:6297836 (Build GRCm38/mm10), where they do not affect any known genes (Goodwin et al., 2019).

Related Strains

5xFAD (C57BL6). Several laboratories have generated their own, in-house congenic lines by backcrossing to C57BL6 mice. 5xFAD mice on a congenic C57BL/6J background are commercially available through The Jackson Lab (JAX MMRRC Stock# 034848, formerly Jackson Lab Stock# 008730), where the retinal degeneration allele Pde6brd1 was bred out of the original strain. The Jackson Lab has observed a less-robust amyloid phenotype in congenic animals compared with those on a hybrid B6SJL background.

Phenotype Characterization

When visualized, these models will distributed over a 18 month timeline demarcated at the following intervals: 1mo, 3mo, 6mo, 9mo, 12mo, 15mo, 18mo+.

Absent

  • Tangles

No Data

Plaques

Extracellular amyloid deposition begins around 2 months, first in the subiculum and layer V of the cortex. Aβ42 also accumulates intraneuronally in an aggregated form within the soma and neurites starting at 1.5 months.

Tangles

Absent.

Neuronal Loss

Neuron loss in cortical layer V and subiculum.

Gliosis

Gliosis begins at 2 months.

Synaptic Loss

Levels of the presynaptic marker synaptophysin begin to decline by 4 months; levels of syntaxin, another presynaptic marker, and PSD-95, a postsynaptic marker, decline by 9 months

Changes in LTP/LTD

Basal synaptic transmission and LTP in hippocampal area CA1 begin to deteriorate between 4 and 6 months

Cognitive Impairment

Impaired spatial working memory in the Y-maze test and impaired remote memory stabilization in a contextual-fear-conditioning test by 4 to 5 months of age.

Last Updated: 15 Mar 2019

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References

Research Models Citations

  1. 5xFAD (C57BL6)

Paper Citations

  1. . ER stress is not elevated in the 5XFAD mouse model of Alzheimer's disease. J Biol Chem. 2018 Nov 30;293(48):18434-18443. Epub 2018 Oct 12 PubMed.
  2. . Temporal memory deficits in Alzheimer's mouse models: rescue by genetic deletion of BACE1. Eur J Neurosci. 2006 Jan;23(1):251-60. PubMed.
  3. . Aβ reduction in BACE1 heterozygous null 5XFAD mice is associated with transgenic APP level. Mol Neurodegener. 2015 Jan 7;10:1. PubMed.
  4. . Intraneuronal beta-amyloid aggregates, neurodegeneration, and neuron loss in transgenic mice with five familial Alzheimer's disease mutations: potential factors in amyloid plaque formation. J Neurosci. 2006 Oct 4;26(40):10129-40. PubMed.
  5. . Molecular Differences and Similarities Between Alzheimer's Disease and the 5XFAD Transgenic Mouse Model of Amyloidosis. Biochem Insights. 2013;6:1-10. Epub 2013 Nov 21 PubMed.
  6. . Phospho-eIF2α level is important for determining abilities of BACE1 reduction to rescue cholinergic neurodegeneration and memory defects in 5XFAD mice. PLoS One. 2010;5(9):e12974. PubMed.
  7. . Intraneuronal Aβ detection in 5xFAD mice by a new Aβ-specific antibody. Mol Neurodegener. 2012;7:8. PubMed.
  8. . Axonal and myelinic pathology in 5xFAD Alzheimer's mouse spinal cord. PLoS One. 2017;12(11):e0188218. Epub 2017 Nov 27 PubMed.
  9. . Galantamine slows down plaque formation and behavioral decline in the 5XFAD mouse model of Alzheimer's disease. PLoS One. 2014;9(2):e89454. Epub 2014 Feb 21 PubMed.
  10. . Evidence for Alzheimer's disease-linked synapse loss and compensation in mouse and human hippocampal CA1 pyramidal neurons. Brain Struct Funct. 2014 Jul 17; PubMed.
  11. . Neuron loss in the 5XFAD mouse model of Alzheimer's disease correlates with intraneuronal Aβ42 accumulation and Caspase-3 activation. Mol Neurodegener. 2013;8:2. PubMed.
  12. . Abnormal vibrissa-related behavior and loss of barrel field inhibitory neurons in 5xFAD transgenics. Genes Brain Behav. 2014 Mar 21; PubMed.
  13. . Amyloid plaque pathogenesis in 5XFAD mouse spinal cord: retrograde transneuronal modulation after peripheral nerve injury. Neurotox Res. 2012 Oct 5; PubMed.
  14. . The noradrenaline precursor L-DOPS reduces pathology in a mouse model of Alzheimer's disease. Neurobiol Aging. 2011 Jun 24; PubMed.
  15. . Visualization of Altered Hippocampal Connectivity in an Animal Model of Alzheimer's Disease. Mol Neurobiol. 2018 Feb 27; PubMed.
  16. . Impairments in remote memory stabilization precede hippocampal synaptic and cognitive failures in 5XFAD Alzheimer mouse model. Neurobiol Dis. 2009 Feb;33(2):229-35. Epub 2008 Nov 5 PubMed.
  17. . Area-Specific Alterations of Synaptic Plasticity in the 5XFAD Mouse Model of Alzheimer's Disease: Dissociation between Somatosensory Cortex and Hippocampus. PLoS One. 2013;8(9):e74667. PubMed.
  18. . Altered theta oscillations and aberrant cortical excitatory activity in the 5XFAD model of Alzheimer's disease. Neural Plast. 2015;2015:781731. Epub 2015 Apr 2 PubMed.
  19. . Reduction of Glucose Metabolism in Olfactory Bulb is an Earlier Alzheimer's Disease-related Biomarker in 5XFAD Mice. Chin Med J (Engl). 2015 Aug 20;128(16):2220-7. PubMed.
  20. . Motor function deficits in the 12 month-old female 5xFAD mouse model of Alzheimer's disease. Behav Brain Res. 2018 Jan 30;337:256-263. Epub 2017 Sep 7 PubMed.
  21. . Age-related deterioration of motor function in male and female 5xFAD mice from 3 to 16 months of age. Genes Brain Behav. 2018 Nov 13;:e12538. PubMed.
  22. . Reduced acoustic startle response and peripheral hearing loss in the 5xFAD mouse model of Alzheimer's disease. Genes Brain Behav. 2017 Jun;16(5):554-563. Epub 2017 Mar 8 PubMed.
  23. . Early detection of cerebral glucose uptake changes in the 5XFAD mouse. Curr Alzheimer Res. 2014;11(5):450-60. PubMed.
  24. . Functional and structural connectome properties in the 5XFAD transgenic mouse model of Alzheimer's disease. Netw Neurosci. 2018;2(2):241-258. Epub 2018 Jun 1 PubMed.
  25. . Temporal gene profiling of the 5XFAD transgenic mouse model highlights the importance of microglial activation in Alzheimer's disease. Mol Neurodegener. 2014 Sep 11;9:33. PubMed.
  26. . A Unique Microglia Type Associated with Restricting Development of Alzheimer's Disease. Cell. 2017 Jun 15;169(7):1276-1290.e17. Epub 2017 Jun 8 PubMed.
  27. . Neonatal Neurodegeneration in Alzheimer's Disease Transgenic Mouse Model. J Alzheimers Dis Rep. 2018 Apr 12;2(1):79-91. PubMed.
  28. . Quantitative Proteomic Analysis of the Hippocampus in the 5XFAD Mouse Model at Early Stages of Alzheimer's Disease Pathology. J Alzheimers Dis. 2013 Jan 1;36(2):321-34. PubMed.
  29. . Large-scale discovery of mouse transgenic integration sites reveals frequent structural variation and insertional mutagenesis. Genome Res. 2019 Mar;29(3):494-505. Epub 2019 Jan 18 PubMed.

External Citations

  1. JAX MMRRC Stock# 034848
  2. JAX MMRRC Stock# 034840

Further Reading