Effects Of Early Experience On Competitive Behavior After Stress In Adult Rats

Competition,as a universal social situation,exists in almost all social groups.Individual competitive behavior is influenced by a variety of proximal and distal factors:proximal factors include opportunity,personal effort,etc.,while distal factors can be traced back to an individual’s early experience.There is evidence that physiological responses to environmental stressors due to different early experiences may mediate behavioral responses to stressors in adulthood.Therefore,it is reasonable to assume that different types of early experiences have a significant impact on competitive behavior in adulthood under stressful conditions.However,most studies on early experience are retrospective studies rather than experimental studies,so it is difficult to determine the causal relationship.Therefore,this study will start from the construction of animal models to manipulate the early experience of rats,and explore the influence of different nature of early experience on the social competitive behavior of rats after adult stress.At the same time,when individuals encounter stressful emotional events in adulthood,whether early experiences of different natures tend to sensitize or habituate their behaviors.This paper consists of two studies.The objective of study 1 was to construct animal models of different early experiences.The rich environment paradigm and chronic Unpredictable stress(CUMS)paradigm were used to conduct early experience intervention in rats,and a series of anxiety-like and depression-like behavior paradigms were used to test the effectiveness of early experience intervention.At the same time,to explore whether different nature of early experience has different effects on competitive behavior of rats.Study two consists of two sub-studies.Study 2A examined whether a self-made forced rotation device could induce stress responses in adult rats.In study 2B,the animal model of early experience in study 1 was used to induce stress response in adult rats by self-made forced rotation device,so as to further explore whether early experience can affect the competitive behavior of adult rats after stress.The following conclusions are drawn from two studies:(1)The early-experience rat model can be constructed by enriching environmental stimuli and CUMS paradigm.Early experience of rich environmental stimuli can effectively alleviate the anxiety-like emotions in rats,while early experience of CUMS paradigm can induce the emergence of anxiety-like emotions in rats.(2)Self-made forced rotation device can induce stress response in rats,which can simulate the stress experience suffered by adults.(3)Early experience had a sustained and stable effect on the competitive behavior of adult rats.Enriched environmental stimuli reduced the success rate of adult rats in the pipeline competition situation,but made the rats show stronger and more stable goaldirected behavior in the contending and predation situations.The rats with early experience of CUMS paradigm did the opposite.(4)Adult rats exposed to CUMS paradigm in the early stage showed adaptation to stress only in the eating test under the novel environment.