大脑储存记忆准确位置获证

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2018-05-25

大脑储存记忆准确位置获证

YetonSunday,somevisitorstotheparkphotographedmembersofafamilygettingofftheircar,notoncebuttwiceinsidethepark.Witnessessaythefamilyincludedatleastonecouple,aseniorcitizenandtwochildren.Attheinterventionoftheguards,theygotbackintothecarbutonlytogetoffagainandbeingforcedtogetintotheircarasecondtime.AlthoughtheparkannouncedonMondaythatitcanprotectvisitorsfromanyattackbecausetheanimalsaresegregated,thefamily"smovewasstilldangerousasthesecuritysystemisnot100percentfoolproof.What"sworse,theyinviteddangersasvisitorswerebannedfromgettingoffcarsonroadsforfearoftrafficaccidents.Theincidentsparkedfiercediscussionsonline,andmanynetizenscomparedittotwopreviousincidents.OnJuly23lastyear,awomansurnamedZhaowhogotoffhercarintheBadalingWildlifeParkwasdraggedawaybyatiger.Shewasmauledandseriouslyinjuredbythetiger,andhermotherdiedtryingtosaveher.OnJan19thisyear,amanclimbedoverawalltoenterthetigers"enclaveinYoungorZooinNingbo,EastChina"sZhejiangprovince.Themanwaskilledbythetigers,andoneofthetigerswasshotdeadduringtheoperationtorescuehim.Intheprevioustwotragedies,manypeoplesurprisinglydidn"tshowsympathyfortherule-breakers.Andthosenetizensthatcriticizedtherule-breakerssayingtherule-breakersdeservetobepunishedsparkedheateddebates.It"stime,however,thatChinesepeoplekeptinmindtheimportanceofobeyingrules.Whatmanypeopleforgetisthefactthatrule-breakersareanunnecessaryburdenonsociety.Topreventpeoplefromrepeatingthefatalmistakesofthevisitorsofsomevisitors,thewildlifeparkhastopostinnumerableguardsalongtheroads,whichinturnincreasesthepriceoftickets.Inotherwords,ordinaryvisitorshavetopayforthewrongdoingsofafewrule-breakers.Infact,manyadministrativemovesarenecessitatedtopreventafewfrombreakingrules.Mostpeoplepayforthemetroridestheytake.Still,everyonehastogothroughticket-checkingmachinesbecauseafewdonotpaythefare.Thismeansallpassengershavetopayfortheticket-checkingmachinesjustbecausesomecommutersbreaktherules.AftertheTempleofHeavenParkinBeijingstartedprovidingfreetissuepapersinitspublictoiletsaweekago,somemediareportssaidsomevisitorswereseentakinglargenumbersoftissuepapers.Todealwiththeproblem,theparkinstalledamachineinallthetoiletsinsidetheparkovertheweekend,andeveryonehastopassavideotesttogetacertainnumberoftissuepapers.Eveninthiscase,rule-breakers,whoarefewinnumber,haveincreasedthefinancialandsocialcostforall.Onlywhentherelatedauthoritiesdeviseamechanismtocompeltherule-breakerstopayfortheincreaseinmaintenanceandsecuritycostscantheyhelppeoplebetterunderstandtheimportanceofobeyingrules.TheauthorisawriterwithChinaDaily.zhangzhouxiang@chinadaily.com.cn

大脑储存记忆准确位置获证

原标题:大脑储存记忆准确位置获证韩国国立首尔大学的一个研究团队日前宣布,他们成功通过荧光蛋白质标记储存记忆的神经元突触,在细胞水平上确认了大脑储存记忆的具体位置为突触(synapse)。实验人员可以用肉眼看到荧光标记。有关成果发表在近日的《科学》杂志上。这是自加拿大心理学家唐纳德-赫普在1949年提出“记忆储存于突触”假说之后,首次通过实验获得验证。

此前由于技术限制,该假说始终没有得到实验证实。

根据研究团队介绍,此前人们已经发现海马体在大脑记忆中起关键作用。

在海马体内部存在着数量庞大的神经细胞单元,每个单元可能有超过10000个突触,通过突触同其他神经单元连接。这些在唐纳德-赫普假说中作为信息存储体的突触,尺寸为纳米级别。

研究人员开发出一种化学检测技术,能够在脑神经元形成记忆时,区分超过一千个突触。

该技术能够分别以黄色和蓝色荧光标记储存有记忆的突触和普通突触。

在实验中,研究人员使用病毒将绿色荧光蛋白(GFP)基因注入神经细胞,当神经元被激活并形成记忆时,荧光出现在突触的末端。

研究者修改了部分GFP基因以获得不同颜色的荧光对突触进行标记。

他们向实验鼠施加电刺激,观察突触刺激后的变化。

实验证实,实验鼠的神经细胞在经历电击之后,通过强化连接神经细胞突触的方式储存相关信息,以帮助实验鼠躲避以后可能发生的电击。

研究发现,逐渐增加电击的强度,能够导致突触中的树突部分数量增加,体积增大。

由此确定电击改变了突触的结构。

据介绍,确认脑细胞储存记忆的具体位置,有助于揭示神经系统退行性疾病的病理。

(责编:郭扬、翁迪凯)。