The development of the retino-tectal projection in Rana pipiens☆
[摘要] Thedevelopmentoftheretino-tectalprojectioninRanapipienshasbeenstudiedbytheintraocularinjectionofsmallamountsof[3H]prolineatlateembryonicandatseverallarvalstages.Aftersurvivalperiodsvaryingfrom1–24hrthedistributionoftheradioactivelylabeledproteinsintheaxonsoftheretinalganglioncellswasstudiedautoradiographically.Itisevidentfromtheappearanceoflabeledproteinsintheopticnerveandchiasmatlateembryonicandearlylarvalstagesthatthereisarapidphaseofaxonaltransportatthesestagesandthatsomefractionofthematerialstransportedinthisphasearedistributedtothetipsofthegrowingaxons.ThefirstretinalfibersreachthecontralateraloptictectumatembryonicStage22;atthisstagetheyareconfinedtotherostrolateralportionofthetectumwherethefirsttectalneuronsaregenerated.Atsuccessivelylaterstagesthefibersappeartogrowacrossthesurfaceofthetectuminageneralrostrolateraltocaudomedialdirection,reachingthedorsalpartofthemid-tectumatlarvalStageIIandthelateralpartofitscaudalthirdbyStageV.However,itisnotuntilrelativelylatelarvalstages(XVIII)thatthefibersreachthecaudomedialregionofthetectum,anditisonlyatthetimeofmetamorphosis(StageXXV)thattheretinalprojectionappearstocovertheentiretectum.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
