Amygdala Injection Of 5-ht The Relationship Between Affect And Behavior, And Gastric Motility, Gastric Motility In Rats Following Chronic Stress

Depression is a unpleasant mind and associated with significant functional disability.Stress is an unspecific adaptive response when animals are confronted with various stimulus.The social stress such as the quickened social rhythm,increasingly furied work competition,make people have more and more mental burdens.It was reported that the activity of digestive systerm was easily effected by stress and emotion.So,the analysis about the effect of stress to digestive system is the key for clarifying the machanism of digestive mobility.The amygdaloid nucleus is attracted tremendous attention for the study of depression,which because chronic stress produces significant effects on amygdaloid neurochemistry,morphology and function.Some people proved that there were both directional nerves between amygdaloid nucleus and hypothalamus,which directly affect digestive mobility.Accumulated evidence indicates a role of the 5-hydroxy-tryptamine(5-HT) in the response to stress and modulation of depression.But,it is unclear the relationship between amygdaloid nucleus 5-HT and digestive mobility.So we want to investigate the effect of intra-amygdaloid nucleus injections of 5-HT on the changes of gastric mobility induced by CUMS.The depression model of rats established by CUMS was used.By observing the behavior of Open field- test,Sucrose preference-test,Forced swimming- test and the changes in body weight,and then examining the effects of intra-amygdaloid injection of 5-HT on the gastric mobility.The result is:(1)Intra-amygdaloid injection of 5-HT could reduce the intrgastric pressure and gastric motility in control group;(2)The results show that the percentage of sucrose preference,the scores of locomotion,rearing, grooming in CUMS group extremely reduced and the body weight gain was negative,meanwhile the gastric mobility was decreased.(3)Intra-amygdaloid injection of 5-HT could markedly improve the gastric mobility reduced by CUMS,which could be affected by the 5-HT1A receptor antagonist Spiperone:5-HT2A receptor antagonist ritanserin could only affected the intrgastric pressure change by 5-HT(4)The improvement of the gastric mobility induced by intra-amygdaloid injection of 5-HT was eliminated with vagotomy.(5)Intra-amygdaloid injection of 5-HT can not improve the behavior of CUMS treated- rats.(6) when we injected 5-HT for 7 days,the behavior of CUMS treated- rats dramaticaly increased to control level.However,the gastric mobility was depressed. These results suggest that CUMS can actually reduce the gastric mobility.Intra-amygdaloid injection of 5-HT can improve the gastric mobility of CUMS treated- rats,which can be affected by the 5-HT1A receptor antagonist Spiperone and also be transmited by vagus.Intra-amygdaloid injection of 5-HT can not improve the behavior of CUMS treated- rats.But when we injected 5-HT for 7 days,the behavior of CUMS treated- rats dramaticaly increased to control level.However,the gastric mobility was depressed.It suggests the behavior and digestive mobility induced by CUMS has different mechanismes.May be there are diverdities in nerval pathway or transmitter or receptor.In addation the accumulation of drugs is an important factor.