长爪沙鼠家庭内的攻击行为可调整其生理特征

长爪沙鼠家庭动态变化所导致的社群压力是一个很少被描述的现象。本研究测定了72只长爪沙鼠的一些生理参数,包括器官重(肝脏、肾脏和脾脏)和血液的生化指标(胆固醇、甘油三酯、葡萄糖和丙氨酸转氨酶)。此外,对家庭内攻击过程中动物的全血细胞数变化也进行了检测。以家庭为单位,所有动物被置于半圈养的实验室条件下,自由取食和饮水。家庭内被攻击的雄性个体的腹下腺显著减小(Mann-WhitneyU-TestU=48.0,P=0.04)。以绝对体重和去脂体重校正后,受到攻击个体的肝脏重量也显著高于未受攻击的个体(肝脏绝对重量Mann-WhitneyU-TestU=169,P=0.02;肝脏相对重量即占去脂体重的百分比U=166,P=0.02),但肾脏重量则显著低于未受攻击的个体(绝对肾脏重量Mann-WhitneyU-TestU=183.5,P=0.04;相对肾脏重量U=137,P=0.005)。被攻击个体的白细胞(U=11.0,P=0.02)和血小板(U=6.0,P=0.004)都显著增加。同时也发现分解作用产生的代谢物有所不同。被攻击的个体具有较高的胆固醇含量(U=13.5,P=0.005)和较低的丙氨酸转氨酶含量(U=13.0,P=0.006)。结果表明家庭内的攻击行为是直接针对那些地位较低的成员,导致其能量物质的释放增加,同时激活了免疫系统以应对由于攻击导致的身体损伤的增加。

Intra-family aggression modulates physiological features of the Mongolian gerbil Meriones unguiculatus

Social stress caused by family dynamics in Mongolian gerbils Meriones unguiculatus is a rarely described phenomenon. Physiological parameters of 72 animals were determined including organ masses (liver, kidneys and spleen) and biochemical blood traits (cholesterol, triglycerides, glucose and alanine aminotransferase). Furthermore, the blood profile was characterized during aggressive intra-family interactions. All animals lived in families kept under ad libitum laboratory conditions in semi-enclosures. It was found that attacked male family members showed a reduced ventral gland pad size (Mann-Whitney U-Test: U = 48.0, P = 0.04). Moreover, they had lighter liver masses than the non-attacked ones referred to absolute body mass and fat free mass (FFM; absolute liver mass: Mann-Whitney U-Test: U = 169, P = 0.02; relative liver mass % FFM: U = 166, P = 0.02) and lighter kidney masses (absolute kidney mass: Mann-Whitney U-Test: U = 183.5; P = 0.04; relative kidney mass % FFM: U = 137, P = 0.005). Changes in the blood profile were observed; animals attacked had an elevated number of leukocytes (U = 11.0, P = 0.02) and thrombocytes (U = 6.0, P = 0.004). Moreover, differences in the metabolites from the catabolism were also found. Animals attacked showed higher cholesterol (U = 13.5, P = 0.005) and lower alanine aminotransferase concentrations (U = 13.0, P = 0.006). Based on these measurements, it is to conclude that intra-family aggression was directed against low-ranking family members and resulted in an elevated release of energetic substances and an activation of the immune system as a reaction to the increased physical impairment of the animals involved.