Alzheimer's research using animal models significantly increases understanding of the disease

Dec 15, 2008

Very few species spontaneously develop the cognitive, behavioral and neuropathological symptoms of Alzheimer's disease (AD), yet AD research must progress at a more rapid pace than the rate of human aging. Therefore, in recent years, a variety of animal models have been created – from tiny invertebrates with life spans measurable in months to huge mammals that live several decades. A special issue of the Journal of Alzheimer's Disease (December 2008), assembled by guest editor Diana S. Woodruff-Pak, Temple University, Philadelphia, explores the variety of animal models now being used in AD research and the resulting therapeutic implications.

"Because of the rare instances of spontaneous development of AD pathology in non-human species, animal models have been developed using various genetic, biochemical, or dietary manipulations to approximate full-blown symptoms of the disease," commented Dr. Woodruff-Pak.

"The purpose of this Special Issue of the Journal of Alzheimer's Disease (JAD) is to provide an overview of the available animal models of AD and to highlight the power of these models in elucidating mechanisms and treatments. To bridge the wide gap between the molecular biology of AD and clinical therapeutics, it is essential to have valid non-human animal models to investigate disease mechanisms, test treatments, and evaluate preventative strategies and cures. While each animal model has limitations, the value of animal models for research on AD is immeasurable. Our progress in establishing a knowledge base about AD would be slowed, and in some cases prevented, without animal models."

Bringing together 13 contributions from worldwide experts, the models span the fruit fly, mouse, rat, rabbit, dog and non-human primate species. Dr. Woodruff-Pak, in an introductory article, describes the advantages and unique characteristics of each of these models.

The fruit fly model is discussed in an article by Iijima and Iijima-Ando where associative learning and memory can be assessed by olfactory conditioning and can be used to model impairment of human patients with AD. In a contribution by Khurana, the fruit fly can be used to model tau-dependent neurodegeneration, a hallmark of AD and related neurodegenerative disorders.

Wilcock and Colton describe the mouse studies of anti-amyloid-β immunotherapy and how they relate to clinical trials, while the role of estrogen in normal aging and AD is addressed by Foy and associates. Behavioral consequences of tau overexpression are described by Morgan and his group. The article by Pallas and colleagues presents the senescence-accelerated prone mouse strain 8 (SAMP8) as a model of early AD and mild cognitive impairment. Two new transgenic mouse models of AD are described by Colton and her colleagues. As described above, these mice progress through a number of stages of AD in a manner that parallels the disease in humans.

Begum has tested amyloid-β infusions in the rat and describes ways to accelerate the effects so that results can be obtained more quickly and efficiently.

Three articles discuss the cholesterol-fed rabbit as a model for various processes in AD. Sparks discusses how cholesterol in the diet causes accumulation of amyloid-β, whereas copper introduced in the drinking water impairs elimination of amyloid-β. Coico and Woodruff-Pak discuss the eyeblink response in rabbits, a form of associative learning that is severely impaired in AD, and which can be affected by excess cholesterol in the diet. An article by Ghribi demonstrates that feeding rabbits over a long time period with cholesterol causes an increase in the cholesterol content in neurons, which in turn can cause an accumulation of amyloid-β in the brain.

The article by Cotman and Head describes two decades of research with canines as models of normal aging and AD. They provide a summary of the beneficial effects of an antioxidant diet, behavioral enrichment, and amyloid-β immunotherapy.

Finally, the article by Buccafusco documents the numerous preclinical trials that have been carried out in his laboratory using non-human primates to identify cognition-enhancing drugs to treat AD.

Source: IOS Press

Explore further: Second bird flu case confirmed in Canada

add to favorites email to friend print save as pdf

Related Stories

Stirling Range flora nears extinction

Jan 29, 2015

The soil-borne water mould Phytophthora cinnamomi (dieback) has rendered unique vegetation on the peaks of the Stirling Ranges in the Great Southern to the point of being critically endangered.

Recommended for you

Ebola reveals shortcomings of African solidarity

15 hours ago

As Africa's leaders meet in Ethiopia to discuss the Ebola crisis, expectations of firm action will be tempered by criticism over the continent's poor record in the early stages of the epidemic.

Second bird flu case confirmed in Canada

Jan 30, 2015

The husband of a Canadian who was diagnosed earlier this week with bird flu after returning from a trip to China has also tested positive for the virus, health officials said Friday.

What exactly is coronavirus?

Jan 30, 2015

The conflicts in Syria and Iraq are straining public health systems and public health efforts meant to prevent and detect the spread of infectious diseases. This is generating a "perfect storm" of conditions for outbreaks. Among the infections raising concern is Middle East Respiratory Syndrome, caused by a type of coronavirus, which emerged in 2012. ...

Scientists find Ebola virus is mutating

Jan 30, 2015

(Medical Xpress)—Researchers working at Institut Pasteur in France have found that the Ebola virus is mutating "a lot" causing concern in the African countries where the virus has killed over eight thous ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.