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1、63题新东方网络课堂总结1463题新东方网络课堂总结14"PassagelO新老观点对比型（专业性文章）咖啡因提神原理新观点（比较特殊，先出现新观点）Caffeine,thestimulantincoffee,hasbeencalled/zthemostwidelyusedpsychoactivesubstanceonEarth."Snyder,DalyandBrunshaverecently（时间状语，很可能是新老观点对t匕型）proposedthatcaffeineaffectbehaviorbycountering阻石辱theactivityinthehum
2、anbrainofanaturallyoccurringchemicalcalledadenosine.Adenosinenormallydepresses阻碍neuronfiring神经兴奋inmanyareasofthebrain.Itapparentlydoesthisbyinhibiting（重点内容）阻碍thereleaseofneurotransmitters,chemicalsthatcarrynerveimpulsesfromoneneurontothenext.Likemanyotheragentsthataffectneuronfiring,a
3、denosinemustfirstbindtospecificreceptorsonneuronalmembranes.Thereareatleasttwoclassesofthesereceptors,whichhavebeendesignatedAlandA2*7.Snyderetalproposethatcaffeine,whichisstructurallysimilarto*7Badenosine,isabletobindtobothtypesofreceptors,whichprevents阻石辱adenosinefromatta63题新东方网络课堂总
4、结1463题新东方网络课堂总结14"PassagelO新老观点对比型（专业性文章）咖啡因提神原理新观点（比较特殊，先出现新观点）Caffeine,thestimulantincoffee,hasbeencalled/zthemostwidelyusedpsychoactivesubstanceonEarth."Snyder,DalyandBrunshaverecently（时间状语，很可能是新老观点对t匕型）proposedthatcaffeineaffectbehaviorbycountering阻石辱theactivityinthehumanbrainofan
5、aturallyoccurringchemicalcalledadenosine.Adenosinenormallydepresses阻碍neuronfiring神经兴奋inmanyareasofthebrain.Itapparentlydoesthisbyinhibiting（重点内容）阻碍thereleaseofneurotransmitters,chemicalsthatcarrynerveimpulsesfromoneneurontothenext.Likemanyotheragentsthataffectneuronfiring,adenosinemus
6、tfirstbindtospecificreceptorsonneuronalmembranes.Thereareatleasttwoclassesofthesereceptors,whichhavebeendesignatedAlandA2*7.Snyderetalproposethatcaffeine,whichisstructurallysimilarto*7Badenosine,isabletobindtobothtypesofreceptors,whichprevents阻石辱adenosinefromattachingthereandallowsthe
7、neuronstofiremorereadilythantheyotherwisewouId.老观点Formanyyears（证明了是新老观点对比型），caffeine’seffectshavebeenattributedtoitsinhibition阻石辱oftheproductionofphosphodiesterase,anenzymethatbreaksdown分角军thechemicalcalledcyclicAMP.AnumberofneurotransmittersexerttheireffectsbyfirstincreasingcyclicAMP
8、conce
