Medical Case Reports

Biography

Biography: Ghanemi

Abstract

Neurodegenerative diseases represent a hard challenge that the modern medicine andhealth care worldwide have to face due to the high social and economic incidences theyhave, especially among the aged populations. Within this context, Alzheimer’s disease (AD), the most common neurodegenerative disease in the elderly represents agood example. Understanding its pathophysiology and finding an effective and radical cureremain the purpose of researchers around the world. One of the biggest struggles facing anyadvances in understanding the pathophysiology of this disease is the lack of animal modelsthat allow us to both study AD itself and test therapeutic agents. Currently, differentanimal models (AMs) have been reported in the literature and each one has itsspecific features and disadvantages as well. Selecting an animal to develop an AD, the AM requires taking many factors into consideration.First, similarities between the animal and the human being in terms of thefeatures linked to AD should be considered (e.g. genetic profile, biochemical basis andpathogenesis manifestation). Second, the ability to evaluate and assess the symptoms andthe pathological variation of the disease should also be a detrimental element of selection.The approaches commonly used to develop the AM may subsequently limit the applicationand the reliability of the model. For instance, genetic methods areused to introduce AD-specific genes into the brain of the animal so it expresses ADspecificproteins such as amyloid and tau proteins. However, other non-suitable proteinsmay be expressed too. Furthermore, even the desirable proteins may be expressedoutside the suitable area when a virus is used as a vector for those genes. Elements may render the AM defective. Moreover, while validating an AD treatment for such transgenic animals, the possibility that the treatment would have just antagonized the genetic modification remains possible. On the other hand, the evaluation of the AM, the possibility of reporting the variation of symptoms before and after, then the development of the AM, and also the comparison of the symptoms of the same animal after the AM has been built; all this can lead to controversy. Indeed, some symptoms are linked to the memory and the cognitive functions, which cannot always be assessed in animals, due to the difference between human beings and animals in terms of brain functions (e.g. executive function, language, calculating, visual memory, working memory, etc). Another approach may be applied to design an AM, which is the use of chemicals shown or thought to play roles in the pathogenesis of AD such as formaldehyde. Such methodology may also lead to interference since the chemicals may result in symptoms similar to those seen in AD without in fact exhibiting AD pathogenesis, notably with what has been reported about the effects chemicals might have on live cells. Importantly, diet may influence AD development, thus leading to differences between AMs due to possible non-similar diets. Another challenge is the interactions that exist between the neurotransmitters within the nervous system that works as a network. This means that modifying the chemistry of one neurotransmitter within an AM could have an impact on the other neurotransmitters such as dopamine and lead to symptoms related to other neurological or psychiatric diseases (e.g. schizophrenia and Parkinson’s disease) instead of AD. Hence, this finally complicates furthermore the study of AD from a neurobiological viewpoint.However, designing an AM for AD that would mimic all thefeatures of the disease, including inflammation oxidative damage, personality changes and the loss of language skills remains far to achieve. One solution would be to have several AMs. Each one would be the best for one or for a number of symptoms. Therefore, only the summation of the results obtained from those AM would give a panoramic result for both pathway studies and drug evaluation tests, especially if reinforced with in vitro tests that combine a cell culture test with the animal model results.