Cardio-respiratory recordings of hibernating animals

哺乳动物的冬眠能力是表型可塑性的一个引人注目的例子。每年，哺乳动物的冬眠都要经历一系列复杂的形态、生理和行为变化，为环境变化做准备。环境变化会导致能量需求增加，而能量供应减少。冬眠动物为了避免这种冲突，会进入长时间的冬眠状态，根据物种的不同，持续时间从几天到几周不等。在冬眠期间，基础代谢率可降至恒温（非冬眠）水平的1 - 4%，体温比环境温度高几度。在整个哺乳类动物中都能发现进入昏睡和冬眠的能力，这似乎涉及到所有哺乳动物共有的基因的差异表达，而不是诱导冬眠物种特有的新基因产物。在冬眠期间，虽然大多数生物化学和生理过程即使没有完全停止，也会显着减慢，但一些关键功能继续受到精确调节。呼吸就是其中之一。通气仍然需要调节，以使氧气消耗和二氧化碳排泄与新陈代谢相匹配，血液中的氧气、二氧化碳和pH值继续保持稳态。我们一直在研究各种冬眠哺乳动物的心肺适应性，并在开始描述它们对寒冷和缺氧（低氧水平）耐受的机制基础方面取得了良好进展。这些结果不仅为冬眠表型提供了见解，而且为包括人类在内的非冬眠物种的低温呼吸停止提供了基础。我们最大的挑战之一是在进入冬眠和从冬眠中唤醒的过程中获取数据。动物在这个时候对干扰非常敏感，这使得传统的数据收集方式变得不可能。现在有几家公司正在以合理的价格商业化生产无线电遥测装置，使我们能够从植入的传输器中收集数据，从而无需处理动物，也无需使用限制动物活动的硬连线电极和套管。购买这些设备将使我们能够在这些过渡阶段收集以前无法获得的信息。

The ability of mammals to hibernate is a dramatic example of phenotypic plasticity. Each year mammalian hibernators undergo a complex suite of morphological, physiological, and behavioral changes in preparation for environmental changes that lead to increased energy demands at a time of reduced energy supply. Hibernators avoid this conflict by entering extended bouts of torpor that range in duration from a few days to several weeks depending on the species. During torpor, basal metabolic rate can fall to as low as 1– 4% of euthermic (non-hibernating) levels and body temperature to within a few degrees above ambient temperature. The ability to enter torpor and to hibernate, is found throughout the class Mammalia and appears to involve differential expression of genes common to all mammals, rather than the induction of novel gene products unique to hibernating species. During hibernation, while most biochemical and physiological processes are dramatically slowed if not halted altogether, some critical functions continue to be precisely regulated. Breathing is one of these. Ventilation must still be regulated to match O2 consumption and CO2 excretion to metabolism, and blood levels of O2, CO2 and pH continue to be homeostatically maintained. We have been studying the cardio-respiratory adaptations of a variety of species of hibernating mammals and have made good progress in beginning to describe the mechanistic basis of their tolerance to cold and hypoxia (low levels of O2). These results give insight not only into the hibernating phenotype but into the basis of hypothermic respiratory arrest in non-hibernating species, including humans. One of our biggest challenges has been obtaining data during the processes of entrance into, and arousal from hibernation. Animals are very sensitive to disturbance at this time making traditional forms of data gathering impossible. There are several companies now commercially making radiotelemetry units at reasonable prices that would allow us to gather data from implanted transmitters removing the need for handling animals and for hard-wired electrodes and cannulae that restrict animal movement. Purchase of this equipment would allow us to gather information during these transition phases that previously has been unavailable.