Reduced ambient temperature has a damaging effect on mammalian myocardium. Huddling as a cooperative behavior has evolved in social mammals as a strategy to maximize adaptation to environmental cooling. Here, we studied the effects of huddling behavior on mitochondrial morphology, number, and function in the myocardia of Brandt's voles (Lasiopodomys brandtii) under cool environmental temperatures (15 °C). Results showed (1) mitochondrial swelling and cristae disruption in the cool huddling group (CH) and cool separated group (CS). Compared to the control group (CON, 22 °C), damaged mitochondria in the cool huddling and separated groups reached >90%; however, total number of mitochondria in the CH group was similar to that in the CON group. (2) ATP synthase activity was lowest in the CS group, whereas citrate synthetase activity was maintained among the three treatment groups. (3) Bax/bcl2 protein expression in the CH and CS groups was higher than that in the CON group, whereas DNA fragmentation, nuclear number, and caspase3 activity showed no significant differences among the three groups. (4) The protein expression levels of dynamin-related protein1 and mitochondrial fission factor were highest in the CH group. (5) Both protein expression of PINK1 and phosphorylation ratio of Parkin showed the pattern CS > CH > CON. (6) Total number of mitochondria was higher in males than in females. In general, the increased mitochondrial fission level observed in huddling voles partially counteracted the decrease in myocardial mitochondria caused by the increase in autophagy.

降低的环境温度对哺乳动物的心肌具有破坏作用。在社会哺乳动物中，作为一种合作行为挤作一团已经发展成为最大限度地适应环境降温的策略。在这里，我们研究了拥挤行为对布氏田鼠（Lasiopodomys brandtii）心肌线粒体形态，数量和功能的影响）在凉爽的环境温度（15°C）下。结果显示：（1）冷拥挤组（CH）和冷分离组（CS）的线粒体肿胀和ista裂破坏。与对照组（CON，22°C）相比，在拥挤的人群和单独的人群中，线粒体的损​​坏率达到了90％以上；CH组线粒体总数与CON组相似。（2）在CS组中ATP合酶活性最低，而在三个治疗组中柠檬酸合酶活性保持。（3）CH和CS组的Bax / bcl2蛋白表达高于CON组，而DNA片段，核数和caspase3活性在三组之间无显着差异。（4）CH组中与动力相关的蛋白1和线粒体分裂因子的蛋白表达水平最高。（5）PINK1的蛋白表达和Parkin的磷酸化率均显示CS> CH> CON。（6）男性的线粒体总数高于女性。通常，在拥挤的田鼠中观察到的线粒体裂变水平增加，部分抵消了自噬增加引起的心肌线粒体减少。