Alzheimers disease-like pathological lesions in an aged bottlenose dolphin (Tursiops truncatus)

29 Jan 2019

Stylianaki, I., Komnenou, A. T., Posantzis, D., Nikolaou, K., Papaioannou, N.

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Alzheimer’s disease (AD) is the most common neurodegenerative disorder causing dementia. AD-like pathological lesions have been described in human and in several other animal species. In this study, we report AD-like pathological changes observed in the brain of a 40-year-old dolphin (Tursiups truncatus), boosting dolphins as a promising natural model of AD. The amyloid β (Aβ) was detected immunohistochemically as intraneuronal depositions, parenchymal accumulations and limited deposits in the wall of meningeal and parenchymal vessels. Also, neuronal tau positive labelling was noticed. This is the first report to show ApoE immunopositive reaction in dolphins. Glial fibrillary acidic protein positive astrocytes were also observed. Our findings are indicative of early AD or mild cognitive impairment pathology. So, they strongly reinforce the statement that dolphins could be a natural animal model of AD due to their lifespan, brain lesions and Aβ homology with the human peptide.