School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China.
School of Life Sciences, Zhengzhou University, Zhengzhou, Henan Province, China.
Eur J Neurosci. 2021 Mar;53(5):1652-1660. doi: 10.1111/ejn.15012. Epub 2020 Nov 11.
Oxygen (O ) is essential for the survival of most animal species; however, O levels are lower than normal in certain spatiotemporal circumstances. Therefore, animals have to develop some strategies to face and adapt to this plight. This study compared the differences in survival, behavior, and hippocampal neurons under hypoxic conditions between Brandt's voles (Lasiopodomys brandtii) and Kunming mice (Mus musculus). Brandt's voles had longer survival times than did Kunming mice in 5%-6.5% O levels. Significant differences were observed in mortality between Brandt's voles and Kunming mice after 6 hr of exposure to 5%-7% O levels. The novel object recognition test (NORT) and neuronal nuclei staining revealed the presence of species-dependent learning deficits and neuron loss under hypoxic conditions. NORT and neuronal nuclei staining showed that the Kunming mice exposed to 7.5% O levels had significant learning deficits and neuronal loss compared with normoxia Kunming mice. Conversely, Brandt's voles exposed to 7.5% O levels had no significant learning deficits and neuronal loss compared with the normoxia group. Therefore, hypoxia showed significant effects on survival, cognitive behavior, and neuronal loss of the two species. Moreover, Brandt's voles showed stronger hypoxia tolerance than Kunming mice, and Brandt's voles hypoxia tolerance may root in their adaptive evolution to highland habitat environment. This research is meaningful for studying hypoxic adaptation in animals, and will promote the development of therapies for some illnesses such as stroke and cardiac arrest.
氧气（O ）是大多数动物物种生存所必需的；然而，在某些时空环境下，O 水平低于正常水平。因此，动物必须发展一些策略来面对和适应这种困境。本研究比较了布氏田鼠（Lasiopodomys brandtii）和昆明小鼠（Mus musculus）在缺氧条件下的存活、行为和海马神经元的差异。在 5%-6.5%的 O 水平下，布氏田鼠的存活时间比昆明小鼠长。在暴露于 5%-7%的 O 水平 6 小时后，布氏田鼠和昆明小鼠之间的死亡率存在显著差异。新物体识别测试（NORT）和神经元核染色显示，在缺氧条件下，存在物种依赖性的学习缺陷和神经元丢失。NORT 和神经元核染色显示，与正常氧昆明小鼠相比，暴露于 7.5% O 水平的昆明小鼠表现出明显的学习缺陷和神经元丢失。相反，与正常氧组相比，暴露于 7.5% O 水平的布氏田鼠没有明显的学习缺陷和神经元丢失。因此，缺氧对两种物种的存活、认知行为和神经元丢失有显著影响。此外，布氏田鼠表现出比昆明小鼠更强的耐缺氧能力，而布氏田鼠的耐缺氧能力可能源于它们对高原栖息地环境的适应性进化。这项研究对于研究动物的低氧适应具有重要意义，并将促进中风和心脏骤停等一些疾病治疗方法的发展。
