Prof. Dr. Annika Herwig

Research interests: 

The main focus of our research is to understand the mechanisms controlling seasonal adaptations in small mammals. Mammals living in seasonal environments face regular and predictable energetic bottlenecks at a particular time of year. In temperate zones, winter is the critical time when food sources are limited and at the same time ambient temperature is low. Many seasonal mammals show extreme morphological and physiological adaptations to overcome this energetic challenge. 
We mainly work on Djungarian hamsters that precisely adjust reproduction, body mass and metabolism to the time of year. These animals show a particularly remarkable annual body weight cycle that is precisely controlled by photoperiod and moreover, use daily torpor. During torpor, metabolic rate is downregulated by 80 % and body temperature drops to values between 15-25°C – a striking state for an endothermic mammal!
Combining in vivo, histological, biochemical and molecular methods, we aim to identify how the brain controls these profound adjustments of energy balance and metabolism. The underlying regulatory mechanisms are of great interest, since they are able to control body weight and metabolism very precisely in the long-term and over an extreme range. Understanding them is of great interest for basic physiology as well as for translational approaches.  


Djungarian hamster (Phodopus sungorus)
Djungarian hamster
Portrait Annika Herwig

Lab Members:

Dr. Victoria Diedrich
Sabine Schmidt (Technical Assistant)
Andrea Kubitz (Technical Assistant)