Effects Of Circadian Clock Gene Per1b Mutantion On Locomotor Activity And Cognition In Zebrafish(Danio Rerio)

Zebrafish (Danio rerio) is an important model for research on development biologyand mechanism of circadian clock.circadian clock is the key mechanism of regulatingrhythms of organism’s life activity pattens, influencing organism’s behavior rhythmsdirectly,via the light,temperate,season changes and other factors. recent studies showthat zebrafish,the vertebrate model, as a optional model to understand circadianclock pathway.such as the per2mutant affect the circadian clock output pathway and thehomones expression related to circadian clock.studies in zebrafish on per1b gene hasnot been reported.We find that the locomotor activity parameters of larvae and adult zebrafish suchas activity,exploring distance,average speed in per1b mutant are significantly higherthan WT by the condition of LD period,also signifcantly in the staistics and thelocomotor activity of per1b mutant cause the like-hyperacive symptoms,suggerting thatcircadian clock pathway can regulate organism locomotor activity by mutantion of theper1b gene.Simultaneously,the locomotor activity of per1b mutant has significantly higherthan WT by the treatment of MAO inhibitor,indicating that per1b may regulate therelease and degradation of dopamine.using mirror--aggression test paradigm,we findthat the retenioning time in mirror area and averagr speed are higher than WT,also getmore attack numbers compared the WT，indicating per1b gene mutant can regulatedopamine level to induce aggressive behavior associated locomotor activity and mayrelate to the ADHD.Using color-food reward learning paradigm and active-avoidance conditioningparadigm to select the optional behavioral test paradigm for learning and memory in zebrafish,we find that it has a potential preference by red on the retention time in foodreward color area by food reward in red area and green area，the associated memory inthe green area by food reward is not distincted，but using active-avoidance conditioningparadigm to measure the learning and memory abilities in zebrafish,the results showthat the learning and memory abilities in ZT8is better than ZT16，so we can use it tomeasure the learning and memory abilities by circadian clock gene per1b mutant inzebrafish.We use the activite-avoidance conditioning paradigm to test the leaning andmoemory abilities in per1b mutant by electric shock,finding that time of learningcriteria is expanded and retention score is reduced in per1b mutant compared to WTduring the day time,show thar the learning and momory abilities of per1b mutant maybe inhibited.in order to further research the infulence by the per1b mutation,we examinemelatonin in zebrafish brain,which is regulated by Arylalkylamine-N-acetyltransferasethough per1b gene in the circadian clock pathway,so that test the concentration ofmelatonin between per1b mutant and WT,the results indicate that the concentration ofmelatonin in per1b mutant is higer than WT in the day time and the memory ability ofper1b mutant has improved by the treatment of luzindole,which is the melatonininhibitor,while melatonin at night continue to accumulate;we can presume that per1bgene supress the expression of aanat2gene,our research suggest that circadian clockgenes not only influence the behavioral level and cognition,also change the hormonelevel associated the circadian clock pathway.