Familiarity and Physiological Stress Modulate Prosocial Behavior in Rats

• Main Authors: I-Te Hsieh, 謝一德
• Other Authors: Bo-Jau Kuo
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/26849759703745084232

博士 === 國立陽明大學 === 生醫光電研究所 === 100 === Prosocial behavior is a behavioral expression of the intention to benefit others and plays an important role in social interaction. The expression of prosocial behavior is suggested to be motivated by empathy, sympathy, pity, altruism and unselfishness etc. Previous studies have indicated that familiarity and biological stress modulates the expression of prosocial behavior. However, there is no appropriate behavioral model currently available for studying the two factors simultaneously. I aimed to provide a novel animal model which is capable of assessing how familiarity modulates prosocial behavior under various degrees of physiological stress induced by water deprivation. I also attempted to explore the involvement of autonomic nervous system in prosocial behavior. Male Wistar-Kyoto rats (observer rats) were deprived of water for 0, 12 or 24 hours, and then allowed to press a right or a left lever for acquiring 0.5 ml water in the presence of a demonstrator rat, which was a sibling or a stranger. In addition to providing water, one of the two levers simultaneously delivered a 1.5 mA foot-shock to the demonstrator rat. The degree of suffering was assessed by the pain percentage of the observer rat elicited in the demonstrator rat. In addition, I recorded the electrocardiogram for heart rate variability analysis. Hypothesis and aims: The novel animal model can provide a stable, effective and objective indicator for prosocial behavior in rats. The prosocial behavior is influenced by physiological stress, autonomic functioning and familiarity. Conclusion: The study establishes a rodent model for directly, objectively and conveniently assessing prosocial behavior. From this model, I find rats exhibit prosocial acts only under moderate physiological stress. When the stress is life-threatening, relieving it becomes the first priority. In addition, the expression of this prosocial behavior is inversely associated with sympathetic activity.