Hibernation as protection for space mission and radiotherapy
Hibernation has long been proposed as a potential tool for human space travel
Since humans are non-hibernating mammals, research in this area gradually declined after the first human space missions. However, in recent years, a procedure to induce a metabolic state known as synthetic torpor has been developed.
Synthetic torpor may not only serve as an efficient method to conserve resources and reduce psychological stress during long-term exploratory missions, but could also represent a key countermeasure against health risks caused by exposure to cosmic rays.
Figure 3: Synthetic torpor induced by GABA-A agonist muscimol. (A) In an animal exposed to constant darkness at an ambient temperature of 15 °C, repeated injections of muscimol in the rostral ventromedial medulla (RVMM, the black arrows at the top) induced a suspended animation state characterized by a reduced deep brain temperature (Tbrain), heart rate (HR), and electroencephalogram (EEG) voltage, as well as a shift of the EEG power spectrum. No significant changes in arterial pressure (AP) were observed. Infrared images at the bottom show the state of cutaneous vasomotion (B) in the pre-injection period, (C) following the first injection of muscimol in the RVMM, and (D) at end of treatment. Copyright 2013, Society for Neuroscience. Puspitasari, A.; Cerri, M.; Takahashi, A.; Yoshida, Y.; Hanamura, K.; Tinganelli, W. Hibernation as a Tool for Radiation Protection in Space Exploration. Life 2021, 11, 54. doi.org/10.3390/life11010054
Moreover, hibernation, when combined with radiotherapy, could become a promising strategy for fighting cancer in the future. Entering a hibernation-like “deep sleep” state could hypothetically slow down bodily functions and inhibit the spread of tumors within tissues, halting the tumor growth, while also increasing the body’s resistance to radiation. In our lab we are developing new protocols to induce prolonged synthetic hibernation, and for the first time, we are investigating the combination of synthetic hibernation and particle therapy for cancer treatment.