关键词: 饥饿, 能量代谢, 产热, 行为, 重喂食, 小鼠, 可塑性

Abstract:

The significance of plasticity in energy metabolism and behavioral patterns in response to variations of food availability was examined in adult male KM mice acclimated to random food deprivation (FD)for 4 weeks,in which animals were fed ad libitum for a randomly assigned 3 days each week,but were deprived of food for the other 4 days, and then refed ad libitum for another 4 weeks. Food intake was measured using the food balance method,and basal metabolic rate (BMR) and nonshivering thermogenesis (NST)were measured using a closed-circuit respirometer. Behavioral observations were made to examine behavioral patterns including activity, feeding, grooming and resting behavior. The data showed that food intake and gastrointestinal mass increased significantly, and BMR and NST decreased significantly in FD mice compared to controls. Moreover, FD mice had a significantly higher percentage of resting behavior and lower activity than control mice. These parameters were all recovered after 4 weeks of ad libitum re-feeding, indicating significant plasticity. These results suggest that animals can compensate for an unpredictable reduction of food availability by engaging in an energetic strategy, including an increase in energy intake related to food intake, and a decrease in energy expenditure associated with BMR, NST and activity, but not including body fat mobilization. Significant plasticity in energy metabolism and behavioral patterns is shown in mice over a short timescale, which plays an important role in adaptations to food shortage in unpredictable environments with relation to food availability.

Key words: Behavior, Energy metabolism, Food restriction, KM mice, Plasticity, Re-feeding, Thermogenesis