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Can seals help us treat stroke damage?

Stroke is one of the leading causes of death in the western world. During a stroke, blood flow to parts of the brain is obstructed, followed by a rapid decrease of oxygen and energy supply to the brain tissue. From earlier studies it is known that the deep diving hooded seal can tolerate extremely low levels of oxygen (hypoxia). Studying the natural neuronal adaptations of animals could contribute to the development of better disease treatment and enable us to protect the brain from hypoxic damage.

The study of synaptic responses in the hippocampus is a widely used method in neurophysiology studies of rodents but was never before applied to large mammals. By adapting and applying this method to hooded seals, researchers at the University of Tromsø found that seal neurons are able to be active without any oxygen for at least 3 record breaking hours. In comparison, mouse neurons die after ~5min of hypoxia.  Furthermore, it was observed that hooded seal brain slices failed to show paired pulse facilitation (PPF), a neuromodulatory phenomenon that we usually take for granted.  PPF modulates signals by amplifying them if they come in rapid succession, and suppression of this amplification might represent an energy-conservation mechanism used for hypoxia tolerance in these species. 

This study was done as part of a PhD project by PhD Student Samuel Geiseler at the Arctic University of Norway and presented at the 2014 annual conference of the Scandinavian Physiological Society in Stockholm under the title below:

In vitro synaptic responses in hippocampal slices from hooded seals (Cystophora cristata)

GEISELER S.J.1, LARSON J.2, FOLKOW L.P.1

(1) University of Tromsø - The Arctic University of Norway, Tromsø, Norway

(2) University of Illinois, College of Medicine, Psychiatric Institute, Chicago, USA

Photo credit: Samuel Geiseler