Disputas og prøveforelesning - MSc in Biology Fredrik Markussen

Later, at 12.15 he will defend his thesis entitled: "Explorations into the control of torpor arousal cycling in the Golden hamster (Mesocricetus auratus)"

Head of department at AMB Vidar Sørum will lead the disputation.

Popular Science Summary
Some animals, like Golden hamsters, can survive harsh winters by entering hibernation. This is a state where their bodies dramatically slow down, using far less energy. Hibernation is a survival strategy that allows animals to endure cold periods when food is scarce, such as winter. During hibernation, hamsters lower their body temperature to around 7°C, nearly as cold as their surroundings, and stay this way for days at a time. But periodically, they “wake up,” quickly rewarming themselves back to normal temperature for a short time before going back into cold temperature.

Scientists believe there must be an important biological reason for them. However, it’s still unclear what exactly triggers a hibernating animal to rewarm. This research aimed to investigate what is happening inside a hamster’s body and brain during these cycles. Using welfare-oriented methods, we monitored hibernating hamsters and studied their blood and brain fluids. We found that certain support cells in the brain, which are in contact with both the bloodstream and brain fluids, become active just before the animal rewarms. We also discovered that as hibernation continues, products from the gut bacterial flora build up in the blood. When these substances reach high enough levels, they may signal the body that it’s time to “wake up” and restore normal function.

In summary, our findings suggest that hibernating hamsters periodically “wake up” from torpor because products build up during the cold period, and the body needs to rewarm to re-balance metabolism.

Evaluation Committee

• Professor Rob Henning, University of Groningen, the Netherlands (1. opponent)
• Associate Professor Domenico Tupone, University of Bologna, Italy (2. opponent)
• Associate Professor Lynn Butler, Health Faculty, UiT (Internal member and leader of the committee)

Supervisors

• Associate Shona Wood, AMB
• Professor David Hazlerigg, AMB

Streaming

Both the trial lecture and defense and will be streamed and recorded:

• Trial lecture
• Defense

Thesis

 The thesis is available through Munin