2016_性与大脑ppt课件

性与大脑 yxzkp 鸟与鸣叫 成千上万种鸟通过歌唱来交流信息 求偶 宣称领地 通常仅雄性会唱 斑胸草雀 鸟类鸣叫 歌唱是最好的人类语言模型金丝雀 雄性比雌性唱歌强斑胸草雀 仅雄性会唱歌 雌性与歌唱相关神经核团退化或无法辨识 斑胸草雀 仅雄性会唱歌 雌性与歌唱相关神经核团退化或无法辨识 斑胸草雀需要早期类固醇激素来组构他的与鸣叫相关的神经核团环路 晚期需要雄激素来激活这些核团 刚孵化的雌鸟给予雌激素或雄激素处理 他们的与鸣叫相关的神经核团会比正常雌鸟的大 成年时 给予这些雄性化的雌鸟雄激素 他们的与鸣叫相关的神经核团会变得更大 他会像雄鸟那样歌唱 如果年幼时没有给予雌激素或雄激素处理 那么成年后他们不会对雄激素产生反应 但金丝雀的歌唱系统并不依赖于早期性激素的接触 春夏是金丝雀的繁殖季节 斑胸草雀生活在条件恶劣的沙漠地带 没有固定的繁殖季节 一旦食物充沛 条件合适 就可交配 每年春季 雄鸟雄激素激增 刺激与鸣叫相关神经核团增大2倍 神经元形成更大的树突 更多的突触 尤其在雄鸟成年期每年都有新生神经元的不断产生并参与到歌唱的神经环路 到了秋天 雄鸟的雄激素下降 与鸣叫相关神经核团萎缩 金丝雀成年时 高级发声中枢每年都有新神经元产生并参与到歌唱神经环路 同斑胸草雀一生中仅会简单的小调相比 金丝雀的歌复杂精细 每年都有新东西 themalesexhormonepromotesthesurvivalofadult bornneuronsintheHVCbyup regulatingtheexpressionofbrain derivedneurotrophicfactor BDNF 雄激素通过产生BDNF 提高了成年时高级发声中枢新生神经元的存活 Sexualdimorphisminvocalcontrolareasofsongbirds TheRAnucleusinthecanary top andzebrafinch bottom islargerinmales left thaninfemales right Volumesofnucleithatarepartofthesongcircuits areaX HVC andRA arelargerinmalesthaninfemalesforbothcanaries top andzebrafinches bottom AreaXisunrecognizableinzebrafinches TheRtnucleus nucleusrotundus isunrelatedtovocalcontrolandhasasimilarvolumeinmalesandfemales RAnucleus 鸟儿如何学会了歌唱 先天本能与后天学习共同作用 最终才能炼就成熟动听的歌曲 鸣叫 早期感觉阶段 年轻的雄鸟学习和记忆住老师 通常是父亲 的歌唱 感觉运动阶段 年轻的雄鸟开始唱起他那不成熟的歌曲 他通常使用听觉反馈来比较自己的歌与记忆中老师的歌 通过反复试错 他唱起的歌逐渐接近老师的歌了 如果鸟儿在早期感觉阶段 听觉隔离 他还是能唱最基本的歌 反映出唱歌或鸣叫是鸟的本能行为 如果鸟儿在早期感觉期 仅能听到其它种类的鸟儿的歌唱 那他就唱别种鸟儿的歌 这反应出后天环境学习的影响 如果不仅能听到其它种类的鸟儿的歌唱还能听到同种类鸟儿的歌唱 那么鸟儿更倾向于学习同种类鸟儿的歌 在感觉期之后 在感觉运动期之前 如果鸟儿聋了 他的歌将保持不成熟状态 对歌唱而言 感觉运动阶段是重要的 年轻的雄鸟开始唱起他那不成熟的歌曲 他通常使用听觉反馈来比较自己的歌与记忆中老师的歌 通过反复试错练习 他唱起的歌逐渐接近老师的歌了 Thesongmotorpathway red consistingofHVC highvocalcenter高级发声中枢 RA robustnucleusofthearcopallium弓状皮质栎核 andthebrainstemmotornucleithatregulatemusclecontractioninthevocalandrespiratorysystems isresponsibleforsongproduction 歌唱的神经环路 高级发声中枢 弓状皮质栎l 核 发声器官 Theanteriorforebrainpathway black consistingofLMAN 巢皮质巨细胞核外侧部 areaX 前脑基底神经节X区 andDLM medialdorsolateralthalamus内背外侧丘脑 isessentialforsonglearning DopamineneuronsprojecttoandmodulateneuronsinareaX 巢皮质巨细胞核外侧部 前脑基底神经节X区 歌唱学习的神经环路 高级发声中枢 弓状皮质栎l 核 内背外侧丘脑 HVC highvocalcenter高级发声中枢 andRA robustnucleusofthearcopallium弓状皮质栎核 这两个大脑皮层的神经核团类似于哺乳动物的运动皮层 对歌唱非常重要HVCneuronsprojecttotheRA andRAneuronsprojecttobrainstemmotornucleithatcontrolmusclecontractioninthevocalorganandbreathingcenterforsongproduction 歌唱学习脑区 forebrainnucleiLMAN lateralmagnocellularnucleusoftheanteriornidopallium巢皮质巨细胞核外侧部 andareaX 前脑基底神经节X区 老鼠的性与性行为 老鼠的性行为Malerodentsmountfemales malesshowaggressivebehaviortowardintruders particularlysexuallymaturemales inordertodefendtheirterritory 对雌性骑跨行为 为保护领地对入侵者攻击femalerodentsexhibitlordosisbehaviorwhensexuallyaroused assumingaposturethatfacilitatessexualintercourse Femalesexhibitmaternalbehavioraftergivingbirthtopups includingnestbuilding pupretrieval andnursing 脊柱前突 分娩后的母性行为 筑巢 数幼崽 养育 MaleSexualBehavior 下丘脑内侧视前区MPA是雄鼠的性行为控制中枢Thisschematicdiagramshowsapossibleexplanationoftheinteractingexcitatoryeffectsofpheromones genitalstimulation andtestosteroneonmalesexualbehavior 延髓旁巨细胞核 下丘脑腹内侧核VMH是雌性性行为控制中心FemaleSexualBehavior Thisschematicdiagramshowsapossibleexplanationoftheinteractingexcitatoryeffectsofpheromones genitalstimulation andestradiolandprogesteroneonfemalesexualbehavior 旁巨细胞核 inmostmammals includingmiceandhumans sexisdeterminedbythepresenceorabsenceoftheYchromosome PeoplewithasingleXchromosomebutnoYchromosomedevelopintofemales Turnersyndrome occurringin1outof2500girls peoplewithtwoXchromosomesandaYchromosomedevelopintomales Klinefelter ssyndrome occurringin1outof1000boys 性分化关键事件发生在胚胎发生中期 此时 生殖脊在雌性分化为卵巢 雄性分化为睾丸 Itwasdiscoveredinthe1950sthatwhenthegenitalridgewasremovedinuteropriortoovertsexualdifferentiation allembryosdifferentiatedasfemales Thisexperimentsuggestedthatfemaledifferentiationfollowsadefaultpathway andthepresenceoftestesinstructsthemaledifferentiationpathway 生殖脊在明显性分化之前从子宫移除 则胚胎都发育为雌性 说明雌性为缺省分化路径Thus theYchromosomemustcontainsomegeneticfactor s thatexertitssexdeterminationeffectbypromotingtestisdevelopment Asinglegene Sry SexdeterminingregionY wasidentifiedinthe1990s Inhumans XYsubjectswithloss of functionSrymutationsdevelopintofemalesdespitehavingtherestoftheYchromosomeintact thisindicatesthatSryisnecessaryformaledifferentiation 仅Sry基因突变 XY染色体的个体就会发育为雌性Moreover XXmicecarryinganSrytransgeneonanautosomedevelopintomales withcharacteristicmalereproductivesystemandmalesexualbehavior thisindicatesthatthepresenceofSryinfemalesissufficienttoconvertthemintomales 仅将Sry基因转入常染色体 XX染色体的个体就会发育为雄性 TheSrygeneontheYchromosomedeterminesmaledifferentiationviatestosteroneproductionagenecalledthesex determiningregionoftheYchromosome SRY whichcodesforaproteincalledtestis determiningfactor TDF Y染色体性别决定区 SRY 编码睾丸决定因子 通过睾酮的产生来决定雄性的分化 Amajorfunctionofthetestesduringembryonicdevelopmentistoproducetestosterone asteroidhormonethatpromotesthedevelopmentofthemalereproductivesystem masculinization andinhibitsthedevelopmentofthefemalereproductivesystem de feminization Testosteroneandestradiolarethemajorsexhormones Sexuallyinexperienced castratedmales thatis maleswiththetestesremoved donotexhibitmale typicalsexualbehaviors suchasmountingoffemalesandaggressiontowardintrudermales Acuteinjectionoftestosteroneintoadultcastratedmalescanrestorethesebehaviors indicatinganactivationaleffectoftestosteroneinmalesexualbehavior 无性经验的阉割雄鼠不会展示雄性性行为 但是注射睾酮后他们会恢复这些行为 反应出睾酮对雄性性行为的激活效应 Testosteroneissynthesizedfromcholesterolinthetestes Becauseofitshydrophobicnature testosteronecanfreelydiffuseacrosstheplasmamembranetoentertargetcells whereitbindstotheandrogenreceptor Thisbindingtriggersnucleartranslocationofthetestosterone androgenreceptorcomplex whichactsasasequence specificDNA bindingtranscriptionfactortoactivateorrepresstargetgeneexpression Atestosteronemetabolite dihydrotestosterone DHT isamorepotentactivatoroftheandrogenreceptorandisresponsibleforexternalgenitalmasculinizationduringdevelopment Estradiol themajorestrogen femalesexhormone isasteroidhormonemadebytheovariesofsexuallymaturefemales Whileestradiolisoftenregardedasthefemalecounterpartoftestosterone italsoplaysimportantrolesduringmaledevelopment Liketheeffectoftestosteroneoncastratedmales applicationofestradioltoovariectomizedfemales thatis femalesfromwhichtheovarieshavebeenremoved canrestorefemale typicalsexualbehavior suchaslordosis Co applicationofprogesterone anothersteroidhormonethatregulatesfemalesexualbehavior augmentstheeffectofestradiol 雌激素维系雌性性行为起重要作用 cellsthatexpressanenzymecalledaromatasecanconverttestosterone butnotDHT toestradiol Inthesecells therefore testosteronecanexertitsactionbytwomeans 1 bybindingtoanandrogenreceptordirectly 2 bybindingtoanestrogenreceptorafterbeingconvertedtoestradiol Earlyexposuretotestosteronecausesfemalestoexhibitmale typicalsexualbehavior 胚胎期第18天 出生后第10天 Thissensitiveperiodcoincideswithpeaktestosteroneproductioninmalerodents Testosteroneexertsitsorganizationaleffectmainlythroughtheestrogenreceptorsinrodents Duringembryonicdevelopmentinrodents thetestosteroneproducedbythetestesofmalefetusescancirculatethroughthebloodtoreachthebrain 胚胎发育期 雄性胎儿产生的睾酮到达大脑 在芳化酶的作用下转化为雌二醇 导致大脑发生雄性化Bycontrast estradiol whichoriginatesfromtheplacenta isboundtoandsequesteredbycirculating fetoprotein aproteinsecretedbyfetallivercellsintothebloodstream 胎儿肝脏产生的 甲胎蛋白和卵巢及母体胎盘产生的雌二醇结合 导致雌二醇无法达到大脑 Thismeansthatestradiolcannotreachthebrainsofmalesorfemalesviacirculation 导致雌二醇无法到达雌 雄胎儿的大脑However estradiolcanbeproducedlocallywithinthebraincellsofmalesbytheactionofaromataseontestosterone Duringtheearlypostnatalperiod whilethetestescontinuetoproducetestosterone estradiolproductionbyfemaleovariesisnegligible Therefore onlymalebrainscanbeaffectedbyestradiolduringearlydevelopment 出生后的早期阶段睾丸分泌睾酮 卵巢分泌雌二醇几乎可忽略 导致仅雄性脑在发育早期阶段被影响 Theorganizationaleffectoftestosteronehasasensitivewindowofaction experimentsonratsandmicerevealedthattheirsensitiveperiodstartsshortlybeforebirthandspansthefirst10daysafterbirth 性行为的敏感期 窗口期 是出生后的前十天 testosteroneisaromatizationtoestradiolandsubsequentactivationoftheestrogenreceptors First femalemicetreatedwithestradiolduringthefirst10daysafterbirthexhibitmale typicalbehaviorssuchasterritorialmarkingandaggressiontowardintruders Earlyestradioltreatmentalsoreducesfemalereceptivitytomating Second aromataseknockoutmalemiceexhibitprofounddefectsinmale typicalbehaviors Third althoughandrogenreceptorisexpressedintheadultbrain itsbrainexpressionduringthesensitiveperiodoforganizationappearsnegligible Indeed malemicewithbrain specificknockoutoftheandrogenreceptorstillexhibitqualitativelysimilarmale typicalmatingbehavior albeitatareducedlevel Territorialmarkingbehaviorinmale female andneonatalestrogentreatedfemalemice Malemiceurinatethroughouttheircages toppanel atypicalterritory markingbehavior Femalemiceurinateinacorner arrowinthemiddlepanel Femalemicetreatedneonatallywithestrogen NE partiallyadoptthemaleurinationpattern bottom Sexhormonesspecifysexuallydimorphicneuronalnumbersbyregulatingprogrammedcelldeath Sexualdimorphismsvarywidelyacrossspecies Inthebrain dimorphismsaresometimesfound buttheyaresignificantinsomespeciesandnonexistentinothers AnexampleofananimalwithalargedimorphismistheIcelandicsticklebackfish inwhichthemalebrainismuchlargerthanthefemalebrain perhapsbecauseofthecognitivedemandsofnestconstruction courtship andchildcare whicharecarriedoutonlybythemale Dimorphisminbrainsize Thesebrainsarefromadultfemale left andmale right three spinedsticklebackfishthatwerethesamelengthandweight Themalebrainislargerand23 heavierthanthefemalebrain Thescalebarindicates1mm Sexualdimorphisminneuronalnumberwasfirstdiscoveredinthemedialpreopticarea MPOA intheanteriorhypothalamus anareaimplicatedbylesionstudiesasessentialformalecourtshipbehaviorincludingmounting intromission insertionofthepenisintothevagina andejaculation 雄鼠下丘脑内侧视前区MPOA对求偶 骑跨 插入 射精行为很重要 该核团在雄性明显比雌性大NuclearstainingindicatedthattheMPOAwasseveral foldlargerinmaleratscomparedtofemalerats CastrationimmediatelyafterbirthcausedareductioninthesizeofthemaleMPOA whereastreatingfemaleswithtestosteroneatbirthcausedanincreaseinMPOAsize Sexualdimorphisminthemedialpreopticarea MPOA ofthehypothalamus A Nuclearstainingoffemale left andmale right ratbrainsrevealedastrikingsizedifferenceinadenselystainednucleusintheMPOAoftheanteriorhypothalamus arrows Theabsenceofthesuprachiasmaticnucleus SCN inthemalebrainisanartifactofthesectionplane OC opticchiasm B QuantitativeanalysesshowthattheMPOAiseighttimeslargerinmalesthanfemales TheMPOAsizeismarkedlyreducedinmalesthatwerecastratedasneonates whereasfemalestreatedneonatallywithtestosteronehaveincreasedMPOAsize Furtherstudiesindicatedthatthisdifferenceiscausedbyprogrammedcelldeaththatoccursonlyinfemales Inthemalebrain sexhormonesactduringthesensitiveperiodaroundbirthtoinhibitcelldeathprogramsinMPOAneurons 在敏感期 性激素 睾酮 阻断了下丘脑内侧视前区细胞的凋亡 SincethediscoveryofsexualdimorphismintheMPOA additionalsexualdimorphismshavebeenfoundinotherbrainareas includingthemedialamygdalaandbednucleusofstriaterminalis BNST Botharebasalnucleiintheforebrainthatlesionstudieshaveimplicatedinregulatingmalecourtshipbehavior 内侧杏仁核 终纹床核为雄性求偶行为的脑区 雄性核团也比雌性的大 Notallsexuallydimorphicbrainareasarebiggerinmales Theanteroventralperiventricularnucleus AVPV inthehypothalamusislargerinfemalesthanmales consistentwithitsmajorroleinregulatingthefemaleovulatorycycle Sexhormonesalsoregulatesexuallydimorphicneuronalconnections aromatase expressingneuronshavedenserprojectionstoseveralpartsofthebraininmalesthaninfemales includingtheventromedialhypothalamicnucleus VMH akeycenterforregulatingmatingbehavior 下丘脑腹内侧核VMH是雌性性行为控制中心Femalesthatundergoneonatalestrogentreatmentdisplayedmale typicalneuronalnumberandprojectionpatterns indicatingthatthesedimorphismsarelargelyproducedbytheneonatalactionofestrogen Sexualdimorphismofapenilemuscleanditsmotorneurons Sexualdimorphisminneuronsofthespinalnucleusofthebulbocavernosus球海绵体肌脊髓核 SNB ismediatedbytestosteroneactivationoftheandrogenreceptor whichregulatesgeneexpressiontopreventprogrammedcelldeathofapenilemuscleinmales trophicsupportprovidedbythemusclepromotesthesurvivalofitsmotorneurons 睾酮 Sexualdimorphisminthespinalnucleusofthebulbocavernosusmuscle A Thespinalnucleusofthebulbocavernosus SNB isfoundinthemalelumbarspinalcordbutisgreatlyreducedinthefemale ThemotorneuronsofthenucleusarepresentinbothsexesatbirthbutthelackofcirculatingtestosteroneinfemalesleadstodeathoftheSNBneuronsandtheirtargetmuscles Itisthoughtthattestosteroneinthemalecirculationpromotesthesurvivalofthetargetmuscles whichexpresstheandrogenreceptor InresponsetotestosteronethemusclesprovidetrophicsupporttotheinnervatingSNBneurons Thismusclederivedsurvivalfactorislikelytobeciliaryneurotrophicfactororarelatedmemberofthecytokinefamily ThustestosteroneactsonmusclecellstocontrolthesexualdifferentiationofSNBneurons DendriticbranchingofSNBneuronsisregulatedbycirculatingtestosteroneinadultmalerats Inmalesthedendritesarborizeextensivelywithinthespinalcord upperphoto Thefactthatthearborsareprunedinadultcastratedmalerats lowerphoto isevidencethatthisdendriticbranchingdependsonandrogens ThespinalcordisshownintransversesectionandtheSNBneuronsandtheirdendritesarelabeledbyaretrogradetracerinjectedintotargetmuscles sexhormonescanalsoregulateneuronalconnectionsinadults mostoftheexcitatorysynapsesthatprovideinputtocorticalandhippocampalpyramidalneuronsareformedonthedendriticspines Thus spinedensitycanbeusedasaproxyforthedensityofexcitatorysynapsesontoapyramidalneuron Interestingly thedensityofdendriticspinesinhippocampalCA1pyramidalneuronsoffemaleratsfluctuatesnaturallyaccordingtotheestrouscycle spinedensitiesare30 greaterinproestrus whichcorrespondstohigherestrogenlevelsinrats thaninestrus whichisassociatedwithlowerestrogenlevels Ovariectomizationreducedspinedensity whichcouldbepartiallyrestoredbyestradiolapplication Thus thenaturalfluctuationofspinedensityappearstoberegulatedbyestradiol DensityofdendriticspinesinhippocampalCA1pyramidalneuronsfluctuateswiththeestrouscycle GolgistainingshowsthatinCA1hippocampalneuronsthedensityofdendriticspines arrows isabout30 greaterintheproestrus A comparedtotheestrus B phase 嗅觉系统与性行为 studiessuggestthatthemainandaccessoryolfactorysystemscanbothregulatesexuallydimorphicbehavior ThemedialamygdalaandBNSTarebothdirecttargetsofmitralcellsintheaccessoryolfactorybulb suggestingthatsexuallydimorphicnucleiplayaroleinpheromoneperception Informationfromthemainolfactorysystem right projectstodistincttargetsthatalsosendinputtothehypothalamus includingtotheGnRH gonadotropin releasinghormone neuronsintheMPOA GnRHneuronsalsoformreciprocalconnectionswithVMHneurons Theolfactoryamygdalacomplexisdividedintodistinctnuclei includingtheMeAandposteriormedialamygdala MeP andtheanterior posterolateral andposteromedialcorticalamygdala ACN PLCN PMCN AOB accessoryolfactorybulb VNO vomeronasalorgan 梨鼻器官 副嗅球 themainolfactorysystemisessentialformating theaccessoryolfactorysystemdiscriminatessexpartnersinmice 嗅觉 探测外激素 在调控交配行为上扮演重要角色acyclicnucleotidegatedchannelexpressedintheolfactoryepithelia CNGA2 isessentialforolfactorytransductioninthemainolfactorysystem MicethatlackCNGA2areanosmic 主嗅觉系统嗅觉上皮缺乏通道CNGA2则嗅觉缺失 雄性大鼠没有交配和领地保护行为Theaccessoryolfactorysystemutilizesadifferenttransductionmechanism culminatingintheopeningoftheTRPC2channeltodepolarizesensoryneuronsinthevomeronasalorgan 副嗅觉系统的梨鼻器官的感觉神经元的TRPC2通道识别外激素 嗅觉上皮Cnga2mutantmalemiceexhibitedvirtuallynomatingbehaviors includingsniffingtoshowinterest mounting orintromission Theyalsodidnotexhibitaggressivebehaviortowardintrudermalesasnormalmalemicedo mainolfactorysystemareessentialtotriggermatingandterritorialdefenseresponses 主嗅觉系统对雄性的交配和保护领地行为非常重要 Bycontrast 副嗅觉系统的Trpc2knockoutmalemiceexhibitednormalmatingbehaviortowardfemalepartners However theyalsoexhibitedequallyrobustmatingbehaviortowardintrudermales Trpc2knockoutmalemicealsoproduceultrasonicvocalizationtowardothermales abehaviorthatisusuallyreservedforcourtshipanddirectedtowardfemales Thus malemicewithouttheaccessoryolfactorysystemfunctioncannotseemtodistinguishthesexoftheirpartners 副嗅觉系统在交配时辨别雌雄上起重要角色 正常的雄性在只和雌性交配 攻击雄性 但是副嗅觉系统损害后 对雌雄老鼠都要交配 对入侵的雄鼠也发出了正常时只对雌鼠发出的求爱超声波 Hisaccessoryolfactorysystemenableshimtorecognizethepartnermouse ssexandswitchhisbehaviorfrommatingtofightingifhedetectsthattheothermouseisamale sensoryneuronsandmitralcellsoftheaccessoryolfactorysystemhavebeenidentifiedthatarespecificallytunedtoacombinationofsexandstrainsignalsfromothermice Whatisthefunctionoftheaccessoryolfactorysysteminfemales AnalysisofTrpc2mutantfemalemicerevealedasurprisingphenotype Trpc2mutantfemalesproduceultrasonicvocalizationsthatresemblethoseofmales andtheymountotherfemales Theyarealsoimpairedinfemale typicalbehaviors suchasnestbuildingandcaringforpups Thus Trpc2mutantfemalesactasiftheyhadbeenpartiallysex transformed 副嗅觉系统嗅觉上皮缺乏通道CNGA2则嗅觉缺失 雌性大鼠发出超声求偶 试图与其他雌性交配 好像他们部分变性了 Animplicationfromtheseobservationsisthatfemalesmayhaveretainedaspectsofneuralcircuitsformale typicalsexualbehavior andsignalsfromtheaccessoryolfactorysystemnormallypreventtheactionofthesemale typicalcircuits Pheromonalandhormonalcontrolofmaleandfemalesexualbehavior A Odorantsaredetectedbysensoryneuronsinthemainolfactoryepithelium MOE whichprojectstothemainolfactorybulb MOB andbyneuronsinthevomeronasalorgan VNO whichprojectstotheaccessoryolfactorybulb AOB ManyofthecentralconnectionsoftheMOEandVNOpathwayareanatomicallysegregated B Femalemicepossesstheneuralcircuitrythatcanactivateeithermale blue orfemale red matingbehaviors Inwildtypefemalespheromonesactivatefemalematingbehaviorandinhibitmale typemating Bycontrast inmalespheromonesactivateacircuitrythatwillinitiatefightswithmalesandmatingwithfemales Testosteroneactivatesmalesexualbehaviorinmaleandfemalemice Thedataarefromastudyinwhichthegonadsofmaleandfemalemiceweresurgicallyremovedinadulthood Noneoftheanimalsexhibitedmalesexualbehaviorwithwildtypefemalesfollowingsurgery Afteradministrationoftestosterone matingbehaviorwasrestoredincastratedmales andfemalesdisplayedmalesexualbehavior Thiseffectwasdose dependent atthehighestdosemaleandfemalemiceexhibitedcomparablelevelsofmale typematingbehaviortowardwildtypefemales 总结Aparsimoniousmodelisthatinbothmal