Effect Of Bifidobactera On Behavior And Monoamine Neurotransmitters In Chronic Unpredictable Stress Rats

Objective:To observe the effect of Bifidobacteria on the changes of the behavior and the monoamine neurotransmitters in prefrontal cortex,amygdala,striatum and hippocampus of Depression Model Rats,and to explore the antidepressive mechanisms of the Bifidobacteria.Methods : Divide 40 male Sprague-Dawle(SD) rats into model( CUS) group,control group, Bifidobacteria group(Bif),Fluoxetine group(FLX) and randomLy according to random number table(n=10 each).Rats in CUS group,Bif group and FLX group were all fed lonely and received CUS for 6 weeks.Rats in control group were fed in groups(5 rats in every cage) in standard environment for 6 weeks.Rats in Bif group and FLX group had a lavage with bifidobacteria and fluoxetine respectively during the last 3 weeks every day,while the CUS group and control group were given the same volume of solvent.Every rat went a behavioral assessment before and after CUS and after intervention.Behavioral assessment included sucrose water consumption test,weight measurement,and opend field test(horizontal moving distance,number of vertical,number of faece).Measured the concentration of the neurotransmitters(5-HT,NE,DA) and its metabolites(DOPAC,HVA,5-HIAA) in prefrontal cortex(PFC),striatum(ST), amygdala(AM) and hippocampus(HIP) with CoulArray HPLC at last.Results:(1)Behavioral assessment before CUS:there was no significant difference between CUS group,control group,Bif group and FLX group.(2)Behavioral assement after CUS:coumtion of sucrose water,gain of body weight,distance of horizontal moving and number of vertical of rats in CUS group,Bif group,FLX group were all less than rats in control group,while the groups number of faece were more than rats in control group.(3)Behavioral assessment after intervention:coumtion of sucrose water,gain of body weight,distance of horizontal moving and number of vertical of rats in control group,Bif group,FLX group were all more than rats in CUS group,while the groups number of faece were less than rats in control group.(4)neurotransmitter index:Compared with the control group,the CUS group monoamine neurotransmitters and some of its metabolites in the brain region ST, AM,PFC and HIP decreased significantly.Compared with the CUS group,the Bif group and FLX group monoamine neurotransmitters and and some of its metabolites in the brain region AM,ST,PFC and HIP increased significantly.Conclusion:(1)Behavioral assement after CUS,coumtion of sucrose water,gain of body weight,distance of horizontal moving and number of vertical of rats in CUS group,Bif group,FLX group were all less than rats in control group,while the groups number of faece were more than rats in control group,which mesns the model was successfully established.( 2) The indexes of depressive behavior of model group,Bifidobacteria group,Fluoxetine group is reduced,indicating the presence of depressive behaviorand.The decrease of NE, 5-HT, DA in PFC,ST,AM, HIP,indicating the function of monoamine neurotransmitters in these brain regions is reduced.(3)Fluoxetine can greatly improve depressive behavior in rats, and the mechanism of antidepressant effect is to increase the concentration of 5-HT,NE, DA in the amygdala, hippocampus, prefrontal cortex, striatum.(4)Bifidobacteria can greatly improve depressive behavior in rats, and increase the concentration of 5-HT,NE,DA in the amygdala, hippocampus, prefrontal cortex, striatum,suggested the bifidobactera as like fluoxetine has antidepressant effect.