低体温誘導の記憶へのリスクと可塑性 - 公募研究 2016－2017
Whereas hibernation is common in rodents and other animals, there are only a very few cases of suspected hibernation or states similar to hibernation in humans. Induced hibernation, also known as suspended animation, is the slowing or stopping of life processes without termination by cooling the body down. This technology has great potential for long distance space travel and medicine. Induced hypothermia has been used for open-heart surgeries and other clinical procedures, but the risk for brain functions is largely unknown. In this research, we plan to elucidate the effects of pharmacologically or genetically induced hypothermia on the consolidation of fear or spatial memories.
The research is conducted at the International Institute for Integrative Sleep Medicine (IIIS) at the University of Tsukuba in collaboration between the Lazarus and Sakaguchi laboratories. The Lazarus laboratory has made key contributions to our understanding of how prostaglandin and adenosine receptors in the brain regulate body temperature and sleep. The laboratory uses innovative genetically engineered systems to investigate homeodynamics in sleep and body temperature. Moreover, the laboratory has developed a high-throughput sleep bioassay system, wherein electroencephalogram (EEG) and electromyogram (EMG) recordings are used for experimental assessment of sleep and intraperitoneal thermal sensors are used to measure simultaneously body temperature (Oishi Y, et al. J Vis Exp. 2015, e53678, doi:10.3791/53678). The Sakaguchi laboratory studies behavioral learning and memory paradigms based on fear conditioning. Mice are trained to associate a foot shock with the context in which it occurs. Characteristic “freezing” behavior, which entails complete immobility except for breathing, is used as a measure of fear memory. One day after training, freezing is evaluated in two contexts: Context A, which is the context in which the foot shock was delivered, and Context B, which is a novel context used to evaluate memory specificity. In case it does not show any phenotype, another hippocampus dependent memory paradigm, social interaction memory, is utilized.