Amyloid-beta peptide and phosphorylated tau in the frontopolar cerebral cortex and in the cerebellum of toothed whales: aging versus hypoxia
Simona Sacchini,
Josué Díaz-Delgado,
Antonio Espinosa de los Monteros,
Yania Paz,
Yara Bernaldo de Quirós,
Eva Sierra,
Manuel Arbelo,
Pedro Herráez,
Antonio Fernández
Affiliations
Simona Sacchini
Veterinary Histology and Pathology, Institute of Animal Health, University of Las Palmas de Gran Canaria, Veterinary School, c/Transmontaña s/n, 35416 Arucas
Josué Díaz-Delgado
Laboratory of Wildlife Comparative Pathology (LAPCOM), School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, 05508-270 SP, Brazil
Antonio Espinosa de los Monteros
Veterinary Histology and Pathology, Institute of Animal Health, University of Las Palmas de Gran Canaria, Veterinary School, c/Transmontaña s/n, 35416 Arucas
Yania Paz
Veterinary Histology and Pathology, Institute of Animal Health, University of Las Palmas de Gran Canaria, Veterinary School, c/Transmontaña s/n, 35416 Arucas
Yara Bernaldo de Quirós
Veterinary Histology and Pathology, Institute of Animal Health, University of Las Palmas de Gran Canaria, Veterinary School, c/Transmontaña s/n, 35416 Arucas
Eva Sierra
Veterinary Histology and Pathology, Institute of Animal Health, University of Las Palmas de Gran Canaria, Veterinary School, c/Transmontaña s/n, 35416 Arucas
Manuel Arbelo
Veterinary Histology and Pathology, Institute of Animal Health, University of Las Palmas de Gran Canaria, Veterinary School, c/Transmontaña s/n, 35416 Arucas
Pedro Herráez
Veterinary Histology and Pathology, Institute of Animal Health, University of Las Palmas de Gran Canaria, Veterinary School, c/Transmontaña s/n, 35416 Arucas
Antonio Fernández
Veterinary Histology and Pathology, Institute of Animal Health, University of Las Palmas de Gran Canaria, Veterinary School, c/Transmontaña s/n, 35416 Arucas
Hypoxia could be a possible risk factor for neurodegenerative alterations in cetaceans’ brain. Among toothed whales, the beaked whales are particularly cryptic and routinely dive deeper than 1000 m for about 1 h in order to hunt squids and fishes. Samples of frontal cerebral and cerebellar cortex were collected from nine animals, representing six different species of the suborder Odontoceti. Immunohistochemical analysis employed anti-β-amyloid (Aβ) and anti-neurofibrillary tangle (NFT) antibodies. Six of nine (67%) animals showed positive immunolabeling for Aβ and/or NFT. The most striking findings were intranuclear Aβ immunopositivity in cerebral cortical neurons and NFT immunopositivity in cerebellar Purkinje neurons with granulovacuolar degeneration. Aβ plaques were also observed in one elderly animal. Herein, we present immunohistopathological findings classic of Alzheimer's and other neurodegenerative diseases in humans. Our findings could be linked to hypoxic phenomena, as they were more extensive in beaked whales. Despite their adaptations, cetaceans could be vulnerable to sustained and repetitive brain hypoxia.
