At current temperatures, all hibernators have probably emerged from their winter hibernation and are enjoying the warm weather. However, this is quite different during the cold season. Many small mammals such as marmots, hedgehogs, bats and some hamsters, and even some birds have a particular skill: they can induce a state of inactivity and reduced metabolic rate to significantly lower their energy consumption when food becomes limited and ambient temperatures drop. Fat depots accumulated before the winter, are consumed during hibernation. During this state, known as torpor, their heartbeat and breathing slow down and the body temperature can approach 0°C. To date, the mechanisms underlying the maintenance of cardiac function at low body temperatures are poorly understood. Now, scientists at the Research Institute of Wildlife Ecology at the University of Veterinary Medicine, Vienna, together with colleagues at the University of Groningen in the Netherlands, have found that certain omega-3 and omega-6 fatty acids regulate the cardiac function and hence hibernation. These fatty acids control the process of maintaining a regular heartbeat, achieving lower body temperatures during hibernation and thereby ensuring the hibernator’s survival.
(Web editor 7 May 2013)