The Avian Telencephalic Subpallium Originates Inhibitory Neurons That Invade Tangentially the Pallium (Dorsal Ventricular Ridge and Cortical Areas)

[摘要] RecentdataonthedevelopmentofthemammalianneocortexsupportthatthemajorityofitsinhibitoryGABAergicinterneuronsoriginatewithinthesubpallium(ganglioniceminences).Supportforsuchtangentialmigrationintothepalliumhascomefromexperimentsusingfluorescenttracersorlineageanalysiswithretrovirus,andthephenotypesofmutantmicewithdifferentabnormalitiesinthedevelopingsubpallium.Inthepresentstudy,wedescribetangentialmigrationofsubpallial-derivedneuronsinthedevelopingchicktelencephalon.Usingquail–chickgrafts,wepreciselyidentifiedtheneuroepithelialorigin,time-course,andpathwaysofmigration,aswellastheidentityandrelativedistributionofthediversetangentiallymigratedneurons.Theanalysisofselectivegraftsofthepallidalandstriatalprimordiaallowedustodeterminetherelativecontributionofeachprimordiumtothepopulationofmigratingneurons.Moreover,wefoundthat,likeinmammals,thevastmajorityoftheGABAergicandcalbindin-immunoreactiveneuronswithinthepallium(dorsalventricularridgeandcorticalareas)haveanextracortical,subpallialorigin.Ourresultssuggestthatthetelencephalonofbirdsandmammalssharedevelopmentalmechanismsfortheoriginandmigrationoftheircorticalinterneurons,whichprobablyfirstevolvedatanearlierstageintheradiationofvertebratesthanwasthoughtbefore.

[学科分类] 生物科学（综合）

[关键词] Interneuron;GABA;subpallium;cortex;DVR;telencephalon;tangential migration;neuronal specification