IT'S MY GREAT PLEASURE TO WELCOME DR. SONG-HAI SHI, TO GIVE A SEMINAR TODAY, HE'S FROM SLOAN-KETTERING INSTITUTE AND DID HIS UNDERGRADUATE STUDY AT SHANGHAI UNIVERSITY IN CHINA AND STUDIED SYNAPTIC PLASTICITY IN DR. ROBERTO O LAB AND HIS WORK WAS EXTREMELY SUCCESSFUL. HE HAS STUDIED EMPIRE RECEPTOR TRAFFICKING AND INTEGRATION UPON YOUR ACTIVATION. SO BASICALLY PROVIDING A BASIS FOR SYNAPTIC PLASTICITY AND FROM THERE, HE WENT TO THE GEN LAB AT UCSF AND TRAINED THERE FOR FIVE YEARS AND DID GREAT WORK IN STUDY, GENETIC BASIS OF POLARITY ESTABLISHMENT SO WE KEEP HAVING THIS STORY ABOUT HIS PRIOR ACHIEVEMENT AND SUCCESS AS AN INDEPENDENT INVESTIGATOR CIRCULATING THE LAB SO I HAVE BEEN LONG WHILE WANTING TO MEET HIM AND HE'S THE FIRST NAME ON MY LIST SO WHEN I HAVE THE OPPORTUNITY TO HAVE A SPEAKER FOR NEUROSCIENCE, SO I'M LOOKING FORWARD TO HEAR ABOUT HIS RECENT WORK ON THE LINEAGE DEPENDENT ASSEMBLY OF THE NEOCORTEX. THANK YOU. >> THANK YOU FOR MUCH FOR THE INVITATION AND KIND INTRODUCTION. IT'S A GREAT PLEASURE TO BE HERE, TO MEET MANY OLD FRIENDS AND MAKE NEW FRIENDS HERE, OF COURSE ALL RESEARCH IS FUNDED BY NIH AND IT'S A PRIVILEGE TO COME HERE AND TELL YOU WHAT WE HAVE BEEN DOING THE PAST COUPLE OF YEARS SO MY LAB FOCUSED ON THE SARKLE IN THENY O CORTEX AND I WILL TELL YOU SOME EFFORT IN THE PAST FEW YEARS, IF THERE'S ANY QUESTION, I WOULD BE HAPPY TO DISCUSS TOWARDS THE END. SO I THINK FOR THIS AUDIENCE I DON'T HAVE TO INTRODUCE MUCH ABOUT THENY O CORTEX EXCEPT SAY THANKSGIVING IS ONE OF THE LARGEST BRAIN REGIONS AND WORK INVOLVING BRAIN STRUCTRE IN BLUE HERE, THIS IS A VERY STRUCTURE THAT IS CRUCIAL FOR ALL HIGHER BRAIN FUNCTION FROM PERCEPTION TO LANGUAGE TO COGNITION SO IT'S A GREAT MISSION IN THE FIELD TO TRY TO UNDERSTAND HOW THIS BRAIN STRUCTURE IS ASSEMBLED AND HOW IT FUNCTIONS TO CONTROL THE HIGHER BRA FUNCTION AND IT'S HIGHLY COMPLEX HERE, BILLIONS OF NEURONS IN HUMAN CORTEX AND MILLIONS OF NEURONS THAT FORMS TRILLIANS OF SYNAPSES SO THERE'S A GREAT LEAD TO UNDERSTAND HOW THE BASIC COMPONENT OF THENY O CORTEX GENERATES AND INVOLVED THE NEURONS BEING POSITIONED IN THE RIGHT LOCATIONS AND HOW THEY FUNCTION IN THE CIRCUIT TO CONTROL THE BEHAVIOR OF THE ANIMALS. SO I'D LIKE TO DISCUSS WITH YOU SOME EFFORTS TO TRY TO ADDRESS THE NEW GENESIS AND MIGRATION AND HOW THOSE EARLY DEVELOPMENTAL PROCESS CAME THROUGH THE FUNCTION OR CIRCULAR SAMPLE IN IN THE CORTEX, SO BEFORE I GET INTO THE DETAILS, I WOULD LIKE TO SHARE WITH YOU SOME OF THE THINGS WHEN I THINK ABOUT THIS QUESTION, BECAUSE THIS IS A NEW DIRECTION WHEN I STARTED MY OWN LAB ABOUT NINE AND HALF YEARS AGO, SOPHISTICATEDY WHEN WE THINK ABOUT CORTICAL DEVELOPMENT, THEY ARE TWO SEPARATE AREAS, SO THE FIRST IS ABOUT EARLY DEVELOPMENT OF THE CORTEX WHICH IS MORE I. HOW DO WE PRODUCE NEURONS AND GLIAL CELLS AND WE THINK ABOUT THE FUNCTIONAL ORGANIZATION AND WE THINK OF A CIRCULAR ASSEMBLY OF OPERATION AND THOSE USE DIFFERENT LANGUAGE SO THE EXPERTISE ARE DIFFERENT SO FOR EXAMPLE, THE EARLIER CORTICAL DEVELOPMENT WE TALK ABOUT TRANSCRIPTION FACTORS AND MIGRATION AND MOLECULAR PATHWAYS BUT WHEN WE TALK ABOUT FUNCTIONAL ORGANIZATION OF THE CORTEX WE TALK ABOUT SYNAPSE STRIKE AND THOSE DYNAMICS OF OSCILLATIONS SO THERE'S VERY LITTLE PERTAINING TO THE FIELD SO WHAT I WOULD LIKE TO PRESENT TO YOU IS A CASE, THOSE TWO AREAS ARE NOT SEPARATE OF WHAT WE ENVISION NOW, IN FACT THERE'S MANY LINKS BETWEEN THOSE TWO AREAS SO THE WORKING HYPOTHESIS WE HAVE IS THAT WE THINK THAT EARLY DEVELOPMENT AT PROCESS, IN TERMS OF MIGRATION CAN HAVE IMPORTANT INFLUENCEOT CIRCULAR SAMPLING OPERATION IN THE CORTEX, IN OTHER WORDS THE COMPLEX CORTEX AND IN A STEP WISE MANNER IN THE SAME TIME TO,A CHIEF THE VERY COMPLEX CIRCUIT. LET ME REVIEW WHAT WE KNOW ABOUT THE NEURONS IN THIS THE CORTEX, THEY ACCOUNT FOR 80% OF NEURONS IN IN THE CORTEX, IT'S ABOUT 20% OF THOSE NEURONS ARE INHIBITED TO GABBA ERGIC NEUTRONS TO CONTROL THE UPROOT AND THOSE TWO TYPES OF NEURONS ARE ORGANIZED IN TWO MAJOR WAYS. THE FIRST LEVEL OF ORGANIZATION, WE ALL KNOW THERE'S STRUCTURE OF THE CORTEX, THOSE ARE JOINED BY [INDISCERNIBLE] THERE'S A CONNECTION HERE IN THE ENTRANCE, SO I WANT TO SHOW THERE'S THIS ORGANIZATIONS AND FROM THE PSF IS TO IN THE WHITE MATTER YOU CAN SEE THIS--EVEN DISTRIBUTION OF THOSE NEURONS SO THEY CAN HAVE THEM THEY ARE ONE, TWO, THREE, UP TO SIX. SO THIS ORGANIZATION IS ONE OF DEFINING FEATURE OF THE CORTEX, EVEN THE DENSITY AND THICKNESS OF IT CAN VARY IN DIFFERENT CORTICAL AREA IN DIFFERENT SPECIES BUT NONETHELESS, THE HORIZONT AT STRUCTURE IS A PROMULGATE FEATURE OF THE CORTEX, SO THIS A STRUCTURAL ORGANIZATION AND THE CORTEX IS ORGANIZING A DIFFERENT DIMENSION, IT'S CALLED FUNCTIONAL COLUMN, IN OTHER WORDS VERTICAL ORGANIZATION IN TERMS OF THEIR FUNCTION, SO THIS IDEA IS BASED ON THE EARLY PIONEER WORK BY MOUMTCASTLE AND THE IDEA IS THAT THE FUNCTIONAL CORTEX ARE ORGANIZED IN THIS VERTICAL DIRECTION AND THIS IS FROM THE SURFACE TO THE WHITE PARTY, AND THEY FORM A FUNCTIONAL UNIT AND THIS INDIVIDUAL UNIT CAN HAVE A VERY DEFINED PHYSIOLOGICAL FUNCTION, FOR EXAMPLE, THE TUNING IN THE VISUAL CONTEXT SO LET ME GIVE YOU A BIT MORE EXPLANATION OF THIS, AND WE KNOW THAT THE NEURONS IN IF THE INDIVIDUAL CORTEX THEY CAN BE ACTIVATED BY PARTICULAR STIMULATION FOR EXAMPLE OR INTEGRATION ACROSS TE VIDEO FIELD SO CERTAIN ORIENTATION OF THE LIGHT BAR CAN ACT WITH ACTIVITY. SO IF YOU TAKE IT AND TAKE IT TO THE SURFACE, HAVE YOU THIS VERTICAL CLUSTER AND NEURONS AND YOU CAN FIND MOST OF THOSE NEURONS AND THE ON THE VERTICAL PASS IS A ORIENTATION TRAINING PROPERTIES AND TAKE WITH THE IT TO THE SURFACE, YOU ENCOUNTER THOSE HORIZONTAL NEURONS, SO THIS INITIAL OBSERVATION PLUS MANY SUBSEQUENT STUDIES LED THIS IDEA OF A FUNCTIONAL COMMENT IN THE CORTEX, IN FACT, HE MADE THIS EXTRAPOLATION BASED ON THE EARLY STUDY, THE MACHINERIES THAT ARE UNIFORM IN THE CORTEX, THEY ARE ASSEMBLE INDEED THE REPETITIVE MANNER WHAT THEIR POSTULATIONS OF THE UNIFORM AND THE PROCESS MAY BE THE SAME ACROSS THE ENTIRE CORTICAL AREA. THE DIFFERENCE IS JUST INPUT, IT'S A DIFFERENT INPUT PROCESS BY THE MACHINERIES AND THEY SPECULATE THAT THERE MAY BE DEVELOPMENTAL MECHANISMS THAT GENERATE THE MACHINE IN THE CORTEX, OF COURSE WE KNOW LITTLE ABOUT HOW THIS CAN GENERATE THIS HIGHLY REPETITIVE MACHINERY IN THE CORTEX. THAT'S ONE OF THE QUESTIONS WE HAVE BEEN THINKING IN THE PAST FEW YEARS. SO ANOTHER QUESTION IS HOW DO WE GENERATE, HOW DO WE ASSEMBLE THOSE REPETITIVE UNIFORM FUNCTIONAL MACHINERIES IN THE CORTEX THAT WE CAN SEE IN DIFFERENT CORTICAL AREA AND DIFFERENT SPECIES. SO LET'S GO BACK TO THE CORTICAL DEVELOPMENT USING MOUSE AS A MODEL. SO THIS IS THE EMBRYONIC MOUSE, MAKING A CLONAL SECTION. YOU HAVE THE VENTRICAL, WHERE IT CIRCULATES IN THIS SPACE, THEY HAVE A VENTRICLE ON MOST OF THE STEM OF PROGENITOR CELLS IN THE NEAR CORTEX RESIDES AND IT WAS DIVIDED TO PRODUCE NEURONS AND THEY WERE MOSTLY RADIO TO OCCUPY THIS STRUCTURE CALLED CORTICAL PLATE, THAT'S NEAR THE CORTEX, SO THE DEVELOPMENT PROCEEDS THE PROGENERATIVE CELLS THAT PRODUCE MANY NEURONS WHERE IT'S READILY EXPAND TO GIVE RISE TO MATURE CORTICAL NEAR O CORTEX AND THEN THE CELLS GET DEPLETED IN THE ADULT CORTEX YOU ONLY HAVE SUBVENTRICLES AND SOME REMAINING ADULT CELL THAT SUPPORT THE THIS. SO WE KNOW MUCH MORE, WE INFECT MORE ABOUT THE PRECISE BEHAVIOR OF THE PROGENTOR CELL, WE KNOW THAT THIS COMES FROM INENTIAL EPITHELIAL CELL, CALLED NEUROACTIN SO THE FIRST PHASE OF THE CORTICAL IS CALLED PREGENITTOR OPERATN SPACE AND THIS IS A SYMMETRICALLY DIVIDE TO PRODUCE A TRANSIENT CELL TYPE CALLED RADIAL GLIAL CELLS AND THEY HAVE A VERY LONG RADIAL PROCESS THAT EXTEND ALL THE WAY FROM THE SAIL INTO THE P. A. SURFACE AND THEY IT'S IN THE SHORT VENTRICLE SURFACE AND THOSE ARE PROGENITOR CELLS AND ALL NEURONS ANDA GLIAL CELLS IN THE CORTEX AND THEY ALSO--THIS VERY INTERESTING BEHAVIOR CALLED INTERCONNCT THE NUCLEOTIDES NEAR AND THEY MOVE UP AND DOWN AS THE CELL PROVIDES TO PRODUC THIS. AND THEN THE SECOND PHASE IS THENY O GENESIS IN THE MIGRATION, WHICH MEANS DURING THIS PHASE, MOST OF THE NEURONS ARE PRODUCED BY THE DIVISION, THERE'S AN INTERESTING FEATURE OF THOSE GLIAL CELLS, THAT MEANS THEY CAN GO THROUGH CELL DIVISION WHICH MEANS THEY DIVIDE AND RENEW TO MAINTAIN THE CELL, AND AT THE SAME TIME POST NEURONS THAT MIGRATE TO THE FUTURE IN THENY O CORTEX AND ALSO THEY CAN GO THROUGH THE TRANSAMPLIFIED PHASE WHICH PRODUCE IT DIRECTLY AND PRODUCING THE PROGENITOR CELLS AND THEY CAN PRODUCE NEURONS AND THIS WAY CAN YOU PRODUCE MORE NEURONS BY THE SAME WAY OF PROGENITOR CELLS. AND INTERESTING FEATURE, THIS MIGRATION IS NOT RANDOM PROCESS, THIS INDEPENDENT INSIDE OUT SESSION OF THE CORTEX WHICH MEANS THE EARLY BORN NEURONS, THEY'RE ALWAYS IN THE DEEP LAYERS AND THE OTHER NEURONS MIGRATE PAST THE EARLY ONE AND SIT ON TOP OF EACH OTHER SO YOU HAVE THIS INSIDE UP WITH THE BUILDING FROM THE BOTTOM LAYER TO THE SUFFICIENT LAYER. THE AND ALSO TOWARDS THE END OF THENY O GENESIS, SOME PROPORTION OF THOSE RADIO GLIAL CELLS WILL GROW TO CONTINUE FOR THE GENESIS THAT CAN PRODUCE THE ASTRO SITE AND THE DENDRITIC CELL ROUGH ATOM SITE. AS SOME OF THOSE EXTENDED TO THE DARK STAGE TO THE NEUROSTEM CELLS. SO THIS IS WHAT WE KNOW ABOUT THE CORTICAL DEVELOPMENT PROGENITOR CELL, BEHAVIORING AS NEUROGENESIS AND THE LAMINAL FORMATION SO I POINT UP A FEW INTERESTING FEATURES OF THOSE CELL BIOLOGY OF THOSE CELLS AND THE MIGRATION, THOSE ARE VERY IMPORTANT SO THE FUNCTION FORMATION OF THE CORTEX AS WE EXPLAIN TO YOU A BIT LATER. SO THERE'S THIS INTERESTING CONCEPT CALLED THIS RADIO COLUMN, IS THAT, AS I SAID INDIVIDUAL RADIAL GLIAL, PROGENITOR CELLS, WHICH MEANS THEY CAN SELF-RENEW THE REGION TO THEMSELVES BUT SINGLE CELLS INDUCE MULTIPLE ROUND OF NEOGENESIS AND PRODUCE A GROUP OF DAUGHTER CELLS, WE CALL SISTER CELLS BECAUSE THEY'RE COMING FROM SINGLE DIVIDING CELLS AND THOSE SISTER CELLS CAN FORM THIS ONK GENIC RADIAL CLONE AND IT PROPOSES A PROLIFERATIVE UNIT ARE RESPONSIBLE FOR PRODUCE THIS POTENTIAL FUNCTION AND THIS YESTERDAY OF HITTING THE DEVELOPMENTAL COLUMN AND THE FUNCTIONAL COMUMKC WHETHER THEY'RE IN A RELATIONSHIP BETWEEN THOSE TWO STRUCTURE ARE NOT TESTED. SO WE DECIDE TO APPROACH THIS TOPIC LIE FIRST ASK WHETHER THERE'S ANY RELATIONSHIP BETWEEN THE DEVELOPMENTAL COMMON SISTER RADIAL GLIAL ON THE SINGLE DIVIDING PROGENITOR CELLS AND CAN FUNCTION DEVELOPNG TO THE UNIT STRUCTURE IN THE CORTEX. SO I'D LIKE TO SUMMARIZE, A FEW STUDIES IN THE FAST FEW YEARS THAT SUGGEST THAT INDEED THERE'S MANY INDEPENDENT ORGANIZATION OF EXCITATORY NEURONS AND THE FIGHTING COMES FROM CELL DIVIDING RADIAL GLIAL PROGENITOR CELLS THAT CAN PERFORM THE SYNAPSE WITH EACH OTHER AND THEY CAN CONTRIBUTE TO THE FUNCTIONAL CONONNIC ORGANIZATION AND THE THEY SHARE PHYSIOLOGIC PROPERTIES AND I WOULD LIKE TO REVIEW SOME OF THOSE KEY OBSERVATIONS WITH YOU. TO ADDRESS WHETHER THESE CAN FORM SYNAPSE WITH EACH OTHER TO FORM THE FUNCTIONAL UNIT, WE FIRST USE A VERY COMMON APPROACH IN THE FIELD USING RETROVIRUS THAT EXPRESS GDFP, TO LABEL THE DIVIDING PROGENITOR CELLS AT THE SURFACE, AT THE EARLY STAGE OFNY O GENESIS AROUND E12, E13 MICE, THAT'S THE BEGINNING FACE OF NEUROGENESIS IN MOUSE CORTEX, AND BECAUSE RETROVIRUS CAN SELECTIVELY INFECT DIVIDING CELLS AND THE IN THE GENOME OF THE DIVIDING CELLS SO THIS WAY WE CAN EXPRESS GFP IN ALL THE PROGENY COMING FROM A SINGLE PROGENITOR CELL SHOWN HERE AND THOSE ARE INDIVIDUAL CLONES, WE USE A LOW RETROVIRUS AND THESE ARE AT DIFFERENT POSTNATAL STAGE AND VERY NICE VERTICAL ORGANIZATION OF A GROUP OF NEURONS SHOWN HERE. SO NOW WE CAN SEE THOSE CYSTIC FIBER NEURONS FORMED THIS ON THE ONCAGENIC COLUMN, THE QUESTION IS, CAN THEY FORM SYNAPSE, CAN THEY FORM SYNAPSE IN A PREFERENTIAL WAY, SO WE HAVE TO PERFORM THE RECORD AS SHOWN HERE BECAUSE WE WANT TO DETECT A SYNAPSE FORMATION THAT IMPRESES GFP BUT YOU WANT TO KNOW WHETHER THE [INDISCERNIBLE] FORM SYNAPSE WE HAVE NEARBY CONTROLS AND THAT'S THE EXPRESSING CELLS, JUST NEXT TO THE GFP EXPRESSING CELLS AND WE WOULD RECORD THE FULL CELLS FOR A SYNAPTIC ACTIVITY BETWEEN THOSE FOUR CELLS, SO IF THE SISTER CELLS CAN FORM SYNAPSE WE WANT TO SAY WHETHER THEY CAN [INDISCERNIBLE], IT MEANS THAT THESE GREEN CELLS WILL HAVE MORE LOOD VERSES THE GREEN-NONGREEN CELLS SHOWN HERE SO THIS IS ONE OF THE--THIS IS ONE OF TED EXPERIMENTS SHOWN HERE, SO THOSE ARE TWO SISTER CELLS SITTING THERE IN THREE AND FIVE, AND YOU CAN SEE THE PIPETTES AND THE SISTER CELLS ARE IN YELLOW AND CELL TWO AND FOUR IN THE MOUSE SISTER CELLS NEXT TO THE GREEN SISTER CELLS THEY WILL TRIGGER ACTION POTENTIALS FROM ONE OF THE CELLS AND IT WILL SEE WHICH CELL WILL RESPOND TO THE TRIGGER IN THE CELLS TO PROBE THE SYNAPTIC ACTIVITY AND IN THIS CASE, WE FIND A UNIDIRECTION OF SYNAPSE FORMING BETWEEN CELL LINES AND THREE, BECAUSE THEY'RE SISTER CELLS AND POST SYNAPTIC RESPONSE TO THE PRESYNAPTIC POTENTIA AND OTHER COMBINATION HAVE THE SYNAPTIC CURRENT AND SUGGEST THAT YOU HAVE THE DIRECTION BETWEEN SISTER CELL ONE AND THREE. SO IF WE PULL ALL THE DATA TOGETHER, WE FIND IS THAT THERE'S A MUCH HIGHER PROBABILITY FOR SISTER CELLS TO HAVE A FUNCTIONAL EXCITATORY SYNAPSE, THAT EXRECORD AND THEY'RE SENDING THE DIFFERENT LAMINAL STRUCTURE AND BETWEEN THE GREEN AND NONGREEN, THOSE ARE THE NONSISTER CELLS, DISTANT PART NERMALTAL CELLS, THE PROBABILITY OF CONNECTIVITY IS RATHER LOW, FOR FIVE-10%. SO THIS SUGGESTS THAT NOT OHM FORM SYNAPSE WITH EACH OTHER, THEY CAN FORM SIN ASPARITATE WITH EACH OTHER COMPARED TO NONSISTER CELLS SO ANOTHER FEATURE OF THE CORTEX IS THAT THEY MISDIRECTIONS OF THE SYNAPTIC FLOW, FOR EXAMPLE, ON THE INHUT RECEIVING, THE SYNAPSE MUST FORM A LAYER TWO OR THREE. AND LAYER TWO, TO THREE, FIVE, AND SIX AND THERE'S CONNECT IVBETWEEN LFOUR-FOUR AND L-FIVE, AND SIX, AND WE EXPECT THOSE SYNAPSE WILL SHARE SIMILAR DIRECTION AS THE MATURE CIRCUIT SHOWN HERE AND INDEED THAT'S WHAT WE FIND. WE FIND THE CONNECTIVITY OVER ALL AND IT'S VERY MATURE TO THE INTERCORTICAL CONNECTIVITY AND THOSE WE SUGGEST THE SYNAPSE WITH THE SISTER CELLS ARE LIKELY VERY IMPORTANT FOR THE MATURE INFORMATION FLOW IN THE CORTEX. SO WE'VE SHOWN THAT THEY CAN FORM SYNAPSE WITH EACH OTHER AND THEY CAN FORM IN A UNIQUE WAY, IN A SPECIFIC WAY AND THEN THE QUESTIONS, WHETHER THOSE SYNAPSE FORM BETWEEN SISTER CELLS ARE IMPORTANT, VERY IMPORTANT FOR THE COLONIC CIRCUIT ORGANIZATION OF THE CORTEX, AS I MENTIONED IN THE VISUAL CORTEX, HAVE YOU THIS ORIENTATION TUNING ACTIVITY AS SHOWN HERE SO EACH VERTICAL ASSEMBLED CELL HERE, THIS IS CROSSED WITH OCULAR DOMINANT COLUMN AND IT WAS NOT AS ACTIVITY, IN A MUCH HIGHER RESOLUTION, AS A SINGLE CELL RESOLUTION, THAT IS THE WORK DONE BY OHKI AND REED LAB, EACH COLOR HERE REPRESENTS AN ORIENTATION TUNING DIRECTION. AND YOU CAN SAY INDIVIDUAL CELLS HAVE A VERY DEFINED ORIENTATION TUNING PROPERTY SO IF THE SISTER CELLS, CAN FORM SYNAPSE WITH EACH OTHER, IF THEY ARE FUNCTIONAL UNIT, THEY WOULD EXPECT THE SISTER SELL TO SHARE SEMINAL PROPERTIES MUCH MORE THAN NONSISTER CELLS, TO TEST THAT WE COLLABORATE WITH A GROUP AT UC BERKELEY FOR THIS, AND WE EXPRESS GFP IN THE V-ONE MOUSE AND WE CAN LOAD THOSE WITH THE CALCIUM INDICATOR IN GREEN AND THEN WE CAN MAP OUT THE SISTER CELLS TUNING PROPERTIES, WITH A MOUNT OF SISTER SELLS AND THEY COMPARE THE DIFFERENCE IN TERMS OF TUNING SPECIFICITY IN THE DNA COMBINATION INCLUDING MANY OF THOSE NONSISTER CELLS SHOWN HERE AND FINALLY, IN A NONSISTER SELL COMPARISON WE CAN FIND THE DIFFERENCE BETWEEN THE TWO CELLS AND THE ACTIVITY DIFFERENCE IS EVENLY DISTRIBUTED ACROSS ALL DIFFERENCE SHOWN HERE BUT WHAT WE FIND IN THE SISTER CELLS ARE MUCH SIMILAR COMPARED TO NONSISTER WHICH MEANS THE ORANTIENTATION DIFFERENCE IS IN THE ZERO TO 30-DEGREE SO THERE WE ARGUE THAT NOT ONLY SISTER CELL CANS FORM SYNAPSE WITH EACH OTHER BUT THOSE THAT SHARE HIGH DEGREE OF ORIENTATION TUNING ACTIVITY. SO THOSE SUGGEST THAT THE SISTER CELLS CAN FORM CHEMICAL SYNAPSE WITH EACH OTHER AND THESE ARE IMPORTANT FOR THE FUNCTIONAL COLONIC ORGANIZATION IN THE CODING, AND FUNCTIONAL COLORDER OF MICRONS IN THE CORTEX AND THE SECTION IS WHAT DRIVE THIS IS SYNAPSE FORMATION BETWEEN THE SISTER CELLS AND WHAT WE FIND IS THAT BEFORE WE CAN DETECT THE CHEMICAL SYNAPSE, WE CAN DETECT THE COUPLING IN THE SISTER CELLS. THIS IS NOT GOING TO HAPPEN IN THE FIRST WEEK WHERE THE CHEMICAL ETHNICITY IS MUCH RARE BUT THEY CYST EXPOSURE TO RADIATION CELLS CAN FORM THE [INDISCERNIBLE] ELECTRIC SYNAPSE. WE SHOW THAT THIS ELECTRIC COUPLING CAN ALLOW SISTER CELLS TO HAVE SINGLIZED ACTIVITY AND THIS PROMOTES THE FORMATION AND THE FORMATION BETWEEN SISTER CELL SYSTEM IMPORTANT FOR THIS CHEMICAL SYNAPSE. THEN THE QUESTION IS, WHY THE SISTER CELLS CAN FORM COUPLING DURING THE FIRST SO WHAT IS THE ORIGIN OF THIS DEPENDENT SYNAPSE FORMATION SO I'D LIKE TO SHARE SOME MORE RECENT DISCOVERY WHERE WE FIND THAT THIS DEPENDENT INSIDE OUT RADIAL MIGRATION WITHIN THE MINUTE, FOR THOSE INITIAL ASSEMBLING OF THE VERTICAL CIRCUIT THIS COMES BACK TO THE DEVELOPMENTAL PROCESS ABOUT THE CELL MIGRATION AND NEUROGENESIS, SO I SHOW THAT THE PROGENITOR CELLS CAN GO WITH A MULTILE ROUND OF PROGENESIS AND THOSE NEURONS AND RADIO GLIAL FIBER AND THIS INSIDE OUT PROFESSION WHICH MEANS EARLY [INDISCERNIBLE] AND LATER [INDISCERNIBLE] WILL PASS THE SISTERS TO SIT ON TOP OF THEM. SO THE FIRST QUESTION IS CAN WE DETECT THE ACTUAL COUPLING BETWEEN THE PROGENITOR CELLS AND THE [INDISCERNIBLE] WE CAN ALMOST DETECT HUNDRED PERCENT OF ACTIVITY, AND THEN IN THE UNPAIRED WE ONLY SEE A COUPLE OF THE COUPLING SO AS SOON AS THE CELLS ARE PRODUCED THERE A FUNCTIONAL INTACT BETWEEN THE LINEAGE AND ALSO WE CAN FIND THAT WHETHER THE MIGRATING SISTER CELLS, WITH THE MIGRATE TO THE FINAL FOGS CAN PERFORM ELECTRIC COUPLING AND THEY'RE AGAIN SHOWN HERE AND WITH THE EMBRYONIC STAGE, THE SISTER CELLS ARE COUPLED AND AT THIS STAGE, THERE'S ELECTRIC COUPLING BETWEEN THE NONSISTER PAIRS NEXT TO EACH OTHER SUGGESTING THAT INITIAL COUPLING IS RATHER SPECIFIC WITH THE EXCITATORY NEURONS MIGRATING TO THE FINAL DESTINATION. THEN THE QUESTION, IF THIS INSIDE OUT MIGRATE PASSED EACH OTHER, THE ELECTRIC SYNAPSE FORMATION IS IN DIRECT CONTACT WITH THE TWO CELLS SO THIS SUGGESTS THAT THE INSIDE OUT MIGRATION MIGHT BE CRUCIAL FOR THIS FUNCTIONING WITHIN AN IMAGE SO THE TEST THAT WOULD TAKE A BUNCH OF THE RELAY MICE, MANY OF YOU PROBABLY HEARD ABOUT THIS MICE BASE THIS HAS THE NEURONAL MIGRATION INSTEAD OF THE DEPENDING THEY HAVE IS IT IT SHOWN HERE SO IF WE LOOK AT THE MARKERS FOR EXAMPLE, THIS IS A [INDISCERNIBLE] SURFACE WHITE MATTER AND THESE ARE THE SUPERFICIAL CELLS AND THESE ARE THE DIP DAPI LAYER CELLS AND THOSE ARE DIFFERENT LAMINA IN THE CORTEX AND THEY WERE SITTING ON TOP OF THE NEURONS BUT IN THE RELAY MICE YOU HAVE THE INVERTEDNY O CORTEX WHICH IS SITTING ON THE TOP OF COX ONE NEURON SO INSTEAD OF INSIDE OUT, THEY HAVE OUTSIDE IN LAM NATION, NOW WHAT WE FIND IN THIS MUTE ANT MICE, THERE'S COUPLING EVERYTHING, AND THE PHOTOCELLS NOT BEING TRAPPED. INSTEAD THEY HAVE DISRUPTED SISTER NEURON COUPLING YOU'LL HEAR BUT THEN THE MICE, PROGENITORS STILL, COUPLE BETWEEN MIGRATING NEURONS THAT NO LONGER COUPLE SUGGESTING THAT INSIDE OUT MIGRATION IS IMPORTANT FOR THE DIRECT CONTACT BETWEEN THE SISTER CELLS AND THIS IS IMPORTANT FOR THE SYNAPSE FORM. SO I HOPE I PRESENTED SOME OF THAT, WE THINK THIS VERY PROBUST DEVELOPMENT AMILLIO THAT'S IMPORTANT FOR ASSEMBLING IN THE CORTEX, INDIVIDUAL PROGENITOR CELLS PRODUCE A GROUP OF CELLS ON THE RADIO GLIAL FIBER TO FORM THIS DEVELOPMENTAL STRUCTURE AND THOSE DEVELOPMENT AT STRUCTURE CAN PRESENT TOGETHER TO CONTRIBUTE TO THE FUNCTIONAL COLONIC CIRCULAR IN THE CORTEX, OF COURSE FOR THIS TO BE ROBUST, THERE ARE TWO IMPORTANT QUESTIONS YOU HAVE TO AASK, FIRST IS THAT WHAT'S THE DIVERSITY OF NEURONS. IN OTHER WORDS THE PROGENITTAL CELLS HAVE TO INCORPORATE THE NEURONS IN DIFFERENT LAYERS AND ANOTHER QUESTION IS THAT IS THIS RADIAL MIGRATION VERY PREDOMINANT COMPARED TO TANGENTIAL MIGRATION BECAUSE [INDISCERNIBLE] THEY ALSO HAVE TANGENTIAL DISPERSION IN THE CORTEX WHICH WOULD MAKE THIS DEVELOPMENTAL MECHANISM NOT SO ROW BUST IF THEY HAVE DISPERSION. SO I'D LIKE TO ADDRESS THOSE TWO QUESTIONS WITH SOME RECENT DATA. SO THIS LAMINAR DISTRIBUTION AND MORE IMPORTANT THAN A DEPENDENT VERSION, BECAUSE THEY'RE GOING AT DIFFERENT TIMES, THEY FUNCTION QUITE DIFFERENT AND THEY ALSO PROP IT UP QUITE DIFFERENT AND MOST OF THE NEURONS, THOSE ARE THE CORTICAL--SUBCORTICAL PROJECTION NEURONS, THEY WERE PROJECTOR TO THE SPINAL CORD, SUPERFICIALLY IN NEURONS AND MOST OF THOSE ARE CORTICAL AND THESE ARE PROJECTED WITHIN THE SAME HEMISPHERE OR PROJECT OTHER SIDE OF THE CORTEX. SO THERE'S THIS DISTINCTION BETWEEN THE DIFFERENT DATE OF LOCATION AND PROJECTION PATTERN. SO THIS RAISES AN IMPORTANT QUESTION THAT IS INDIVIDUAL PROGENITOR CELLS IF YOU PRODUCE A VERTICAL STRUCTURE AND THE ONLY--ONLY SUPERFICIAL LAYER, IT ONLY PRODUCES SUPERFICIAL OR [INDISCERNIBLE] IF THAT'S THE CASE THE UNIT WOULD NOT BE VERY ROBUST. ALSO THERE'S EXTENSIVE EVIDENCE THAT THERE'S TANGENTIAL DISPERSION OF INDIVIDUAL CLONE IN THE CORTEX. SO WE WOULD LIKE TO ADDRESS THIS WITH A SYSTEMATIC QUANTITATIVE WAY AND TO DO THAT WE TOOK ADVANTAGE OF THIS METHOD DEVELOPED BY NATURE NODE CALLED MADM, IT'S A VERSION OF THE MARKERS HERE, JUST TO RUN THIS, INSERTED IN THE STEM, CHROMOSOME LOCUST, SO IT'S THIS EXPRESSION IN THE PROGENITOR CELL, IN THE DNA REPLICATION, YOU HAVE A COPY OF CHROMOSOME, YOU HAVE THIS VERY RARE CHROMOSOME AND THE GFP AND THE SEGREIGRATION OF THE CHROMOSOME AND THE IP OF TWO FUTURE DAUGHTER CELLS AND YOU HAVE A GREEN OR RED IN THIS CASE, BECAUSE THE TWO DAUGHTER CELLS ARE PERMANENTLY MARKED, YOU HAVE TO TRACK THE LINEAGE OF THE CELLS WITH A VERY DEFINED SPECIFICITY, IT'S GTWO X SEGREGATION AND X CLONE AND BECAUSE OF THE DISTINCTION BETWEEN THE DAUGHTER CELLS WITH DISTINCT COLOR, WE HAVE THE PROBE THAT THE BEHAVIORS IN THE PROGENITOR CELLS, THE OPTICAL IMAGESRATIVE OF THE INDIVIDUAL CELL IN A VERY QUANTITATIVE WAY AND OF COURSE THERE'S THE OTHER WAY OF RECOMBINATION GOES WITH THE YELLOW, SO WE HAVE--COMBINE THIS METHOD WITH VERY PRECISE TEMP ROUGH ATOM SPACIAL FEES FISCHERITY FOR EXAMPLE, WITH THE MMX ONE CREE R, AND IT ONLY EXPRESSES [INDISCERNIBLE] AND WE CAN USE TOM OX FIN AND DIFFERENT EMBRYONIC STAGE TO LABEL THE PROGENITOR CELLS AT A VERY DEFINED EMBRYONIC STAGE FOR THE OUTPUT OF INDIVIDUAL PROGENITOR CELLS, THE P-SEVEN-10 AND THE MIGRATION IS COMPLETE OR P21-30 WHEN MOST ACTIVITY IS FORMED IN THE CORTEX. SO HERE I WANT TO GIVE YOU AN EXAMPLE, BUT WHAT WE DO IS THAT WE'RE DO INDUCTION, SHOWN HERE, THIS IS E. R. THAT ONLY LABEL THAT DOES [INDISCERNIBLE] WITH THENY O CORTEX IN THE CAMPUS, AND WE PERFORM THE SECTION AT THE TIME WHEN WE START TO ANALYZE IT, THE RECONSTRUCT THE ENTIRE BRAIN TO COVER THE LABELED NEURONS TO SEE WHAT THE ORGANIZATION OF THE INDIVIDUAL CLONE. SO THIS IS ONE OF THE HEMISPHERE, CAN YOU SEE IN THE CORTEX WE ONLY SEE TWO CLUSTER CELLS AS WE PREDICT, THERE'S THIS RED OR GREEN CLUSTER, THERE IS A YELLOW CLUSTER, OTHER CELL REVISIONS, WITH THE CELL REVISION, FIRST OF ALL WE HAVE TO SEE THE LITTLE SCATTERING OF CELLS, SUGGESTING THAT MOST OF THE NEURONAL MIGRATION OCCURRED IN THE VERTICAL MANNER IN HAD THE CLUSTER TO FORM A RADIAL CLUSTER AND ALSO A VERY LETHAL MIXTURE BETWEEN THOSE TWO TYPE OF CLONE AND THEY SUGGEST THAT INDIVIDUAL CLUSTER LIKELY COME FOM A SINGLE PROTONLE DIVIDING PROGENITOR CELL IN A LOW RESOLUTION AND ALSO WE CAN DO THE LAMINAR INTRUSION SO THOSE ARE--THE SURFACE,NY O FIVE, FOUR, AND SIX, AND WE SEE THE INDIVIDUAL CLONE FROM THOSE BENEFICIAL LAYERS AND SUGGESTING THAT THOSE ARE CAPABLE TO PRODUCE THOSE AND MORE THAN THAT, WE CAN START PROBING THE BEHAVIOR, SO WE KNOW THAT AND ALL THE DEVICES AMPLIFY THE PROGENITOR CELLS AND THEY CAN DIVIDE THOSE [INDISCERNIBLE] AND CAN WE DISTINGUISH THESE TWO TYPE OF DIVISION BY THE RADIAL GLIAL PROJECTION SO WE CAN SEE THE DAUGHTERS AND [INDISCERNIBLE]--SUGGESTING THOSE ARE THE EARLY NEURONS AND ANOTHER COHORT OF CELLS AND ANOTHER COLOR, THEY'RE ALWAYS SPANNING FROM THE DEEP LAYER TO [INDISCERNIBLE] LAYERS AND PRODUCE ONE INTERMEDIA AND OTHER PROGENITOR CELLS THAT CONSTANTLY PRODUCE ADDITIONAL CELLS IN THE LINEAGE. OF COURSE WE ALSO SEE THOSE SYMMETTIC CLONES AND THESE GREEN AND RED CELLS WOOY CAN SEE A LARGE COHORT FROM THE DIP LAYER CELLS SO WE CAN DISTINGUISH FOR THE FIRST TIME IN VIVO AND THE SYMMETRIC CLONE IN THE MOUSE CORTEX. WITH THIS RESOLUTION, WE CAN ASK, WHAT IS THE TRANSITION BETWEEN AMPLIFICATION AND THE GENESIS HAPPENING IN THE CORTEX, IN THE MOUSE CORTEX, THIS TRANSITION HAPPENED BETWEEN E11-E12, BECAUSE AT E10, MOST OF THIS SINGLE PROTONET RICK AMPPLIFICATION CLONE BUT AT E13 LOTS OF THE MAJORITY OF THE JURE O GENIC CLONE SO DURING THIS E11-E12 MAKES THE TWITCH BETWEEN SYMMETTIC PROLIFERATION TO A NEUROGENIC PHASE OF DIVISION. BECAUSE WE CAN MAP OUT THIS TRANSITION WE CAN ASK A INTERESTING QUESTION, FOR EXAMPLE, IN THE RADIAL GLEA PROGENITOR CELLS TO THE NEUROGENIC DIVISION, AND WE MAKE THIS TO INDIVIDUAL PROGENITORS FOR THE CELLS AND THE DEFINE NUMBER OF NEURONS AND WE TRUCK THIS TRANSITION AND WE CAN MAP THE ENTIRE OUTPUT OF THAT GROUP, SO THIS WOULD PULL ALL THAT CLONE BUT YOU CAN FIND THAT THE NORMAL DISTRIBUTION AS SHOWN HERE, ABOUT EIGHT-NINE NEURONS AND THIS INTRUSION SUGGESTS THAT INDIVIDUAL RADIAL GLIAL PROGENITOR CELLS THEY CAN PRODUCE A MORE OR LESS DEFINED NUMBER OF NEURONS WE CALL THIS A UNIT. SO THIS IS TWO, THEN WE WOULD PREDICT IN A SYMMETRIC BEFORE THAT, AND ONE SYMMETRIC AND PRODUCE ONE UNIT IF THE TWO SYMMETRIC PRODUCE FOUR UNIT CAN WE SEE THIS TYPE OF BEHAVIOR IF WE PUT IT ALL TOGETHER AT THE EARLY STAGE? THE ANSWER IS YES. SO THIS IS THE QUESTION WE SEE WHETHER THIS DUPLICATION OF INNY O GENIC UNIT SO THIS A HISTOGRAM OF AN ENTIRE CLONE, AND WE CAN APPROXIMATE THIS BY ONE UNIT AND TWO UNITE AND THREE UNIT AND THIS IS ACTUALLY QUITE REMARKABLE GIVEN THE PROTENTIAL DIFFERENT OF VALID AND RELIABLE I CAN'T BELIEVE AS WE HAVE MORE UNITS ON THE PROGENITOR CELL, AND WE CAN SEE VERY HIGH PICKS AROUND HIGH UNIT SIZE, SO THIS READ OUT SUGGESTS THAT THE IT CAN INDEED PRODUCE MODIFICATION OF THIS UNIT AND SUGGEST THIS IS CLONAL 48URE OF THENY O GENESIS IN THE CORTEX AND THIS IS ALMOST SIMILAR TO WE THINK ABOUT TRANSMITTER REDUCE IN THE TRANSMISSION BECAUSE INDIVIDUAL VESICLE IS HERE SO HERE WE HAVE THIS FRO GENITOR CELL READY TO PRODUCE NEURONS AND A RONDE ORDER OF MICRONS NUMBER OF NEURONS AND A DEFINED NUMBER OF NEURONS ABOUT EIGHT TO NINE NEURONS. AND THIS IS A NEOGENIC PHASE, WHAT IS SYMMET RICK, CAN YOU SEE THE SIZE OF THE NUMBER OF CELLS IS DECREASING, SUGGESTING THE POTENTIAL IS PROGRESSIVELY DECREASING. BECAUSE WE HAVE THIS UNIT OUTPUT WE CAN ESTIMATE HOW MANY OF THE DIVISION OF THE PROGENITIVES ARE DOING SYMMETRIC PHASE TO DO THIS SIZE OF A CLONE, IN OTHER WORDS YOU HAVE TO TIME THIS BY HOW MANY ROUND OF DIVISION TO CALCULATE THE RUN, IF WE DO THAT, WE ACTUALLY CAN LOOK AT THE DISTRIBUTION OF THE PROGENITOR CELLS EACH TIME POINT, E10, 11, 12, BECAUSE YOU WILL FIND THE INTRUSION OF THE POPULATION BEHAVIOR OF THE PROGENITOR AT EACH TIME POINT IS EXACTLY THE SAME. WE CAN'T PUT IT ON THE OVERLAP BETWEEN THE DIFFERENT TIME, SUGGESTING THAT THE DIFFERENT PHASE, THE BEHAVIOR ARE WELL, WELL, DEFINED. THEY ALMOST FALL IN THE SAME TYPE OF PROGRAM AS THEY PROGRESS THROUGH THE DEVELOPMENT. SO THIS SUGGESTING A SIMILAR DEFINED PROGRAM THAT REGULARLY PROFICIENT OF THE PROGENITOR CELLS IN THENY O CORTEX, AS I SAID WE CAN SEE THE DIFFERENCE, DOESN'T MATTER WHAT TIME WE LOOK AT FROM E10 TO E13 AND WE WILL CONFIRM THAT NOT ONLY THE DISTRIBUTION IN EMERGING ITS OF LAMINAL INTRUSION BUT WE HAVE SUPERFICIAL CELLS BUT ALSO THE MARKET EXPRESSION FOR THIS AND THE DIFFERENT SUPERFICIAL LAMINAL MARKER, FOR THE INDIVIDUAL CLONE MOSTLY CONTAINS THOSE NEURONS AS SHOWN HERE. E11 AND E10, THE UNIT CAN [INDISCERNIBLE] AT E12 WE START TO SEE VERY RARE THE PROGENITOR CELLS, THE CELL CYCLE A BIT PREMATURELY AND THEN TO WORK WITH THE LATER STUDY, WE HAVE THE CLONE ONLY HAVE SUFFICIENTLY [INDISCERNIBLE]. SO THIS COMPLETES THE EARLY IDEA ABOUT THE FIRST DEPENDENT GENESIS, AND ANOTHER WAS SUGGESTING THAT THE PROGENITOR CELLS CAN PRODUCE BOTH IN THIS THE NEURONS INSIDE OF PROGRESSIVE MANNER. WHAT ABOUT GLIAL, I MENTION TOWARDS THENY O GENESIS, WE START TO SEE, THERE WAS SUPPOSED TO PRODUCE GLIAL CELLS, IN FACT MOST OF THE PEOPLE IN THE FIELD SUGGEST ONLY THE ASTRO SITE BECAUSE MOSTLY THAST ROW SIGHT AND THE OLIGO DENDRITIC CELL ROW SIGHT, AS SHOWN HERE, WE CAN STOP TO SEE WHETHER THE INDIVIDUAL CELLS PRODUCE GLIAL CELLS, ONLY PRODUCE GLIAL CELLS IN A SMALL FRACTION OF THE PROGENITOR CELLS BECAUSE WE KNOW THE UPWARD OF THE [INDISCERNIBLE] OUTPUT, IF WE COMPARE THE CROSS IN TERMS OF THE NUMBER OF NEURONS IT CONTAINS, WHETHER IT CONTAIN GLIAL CELLS WE CAN FIND THOSE CLONES CONTAIN ABOUT 12 NEURONS, 16% OF THOSE CLONES HAVE GLIAL CELLS, AND THIS IS CORRESPONDING TO ONE GLIAL CELL BECAUSE THIS IS A SINGLE RADIO GLIAL CELL PRODUCE, BUT IN THE CLONES WE HAVE 49 YEAR-OLDS AND THERE'S SIX GLIAL CELLS DURING THE END EVER THENY O GENESIS DURING THIS TRANSITION, ALMOST HUNDRED PERCENT OF THOSE CLONES WILL HAVE GLIAL CELLS SUGGESTING THAT ONE OUT OF 6-RADIO GLIAL CELLS IN THENY O TORTEX AT THE COMPLETION WILL PROCEED TO GLIAL GENESIS AND ROUGH ATOM DUCE THE CELLS AND THEY PRODUCE ASTROCYTE OR DENDROCYTE IN THE CELLS. SO THIS IS HIGHLY CORRELATIVE, AT DIFFERENT PHASES THEY'RE DIFFERENT EMBRYONIC STAGES AS THE TIME [INDISCERNIBLE] YOU CAN ALMOST PREDICT THE INDIVIDUAL PROGENITORS THEY HAVE TO GO THROUGH AND ONCE THEY ENTER THE NEOGENESIS PHASE, THEY PRODUCE [INDISCERNIBLE] FOR ABOUT EIGHT OR NINE NEURONS THEY SPEND [INDISCERNIBLE]. AT THE END OF IN NEOGENESIS, ABOUT 16 PERCENT OF THOSE WILL GO ON TO PRODUCE GLIAL CELLS SUGGESTING POTENTIAL COUPLING OF GLIAL CELLS AND NEURONS IN THE CORTEX. SO IN OTHER WORDS THERE'S ROBUST DEVELOPMENTAL MECHANISM THAT IS IMPORTANT FOR THE FORMATION OF THE FUNCTIONAL COLONIC CIRCULATING AND MISSING THE MOUSE CORTEX. SO OF COURSE, THIS ONLY--VERY SMALL NUMBER OF QUESTIONS FOR EXAMPLE, WE HAVE MANY QUESTIONS THAT REMAINS TO BE UNDER THEM, HOW DO WE SWITCH FROM THIS COUPLING, UNIDIRECT CHEMICAL SYNAPSE THAT WE THINK POTENTIALLY THE INPUT IS VERY IMPORTANT FOR THIS SWITCH AND ALSO WE KNOW THAT INITIAL VERTICAL CONNECTIVITY ONLY SERVE AS A FRAMEWORK FOR THE COMPLEX CIRCUIT OF THE CORTEX, THERE'S A LOT MORE CONNECTIONS THAT HAVE TO PERFORM AND WE HAVE TO RECRUIT IRPT NEURONS AND MORE HORIZONTAL AND CONNECTION OF THIS VERTICAL KIN ECTOMYOSIN, BUT IT PROVIDES A FRAMEWORK HOW WE THINK THE FUNCTIONAL COLUMN CAN BE ASSEMBLED IN THE CORTEX. SO I'D LIKE TO SHARE THE EFFORT IN TERMS OF INTERNEURONS, I THINK THERE--IN TERMS OF INTERNEURONS BECAUSE YOU HAVE RATHER A UNIQUE POPULATION OF NEURONS, THEY COME FROM A DIFFERENT ORIGIN. FROM THE EMBRYONIC VENTRAL [INDISCERNIBLE], IT PRODUCES 70% OF CORTICAL NEURONS FOR THE CORTEX AND MIXED WITH EXCITATORY NEURONS TO PERFORM THE FUNCTIONAL CIRCUIT AND MOST OF THEM WITH THE FIELD, FROM THE MIGRATION FROM THE NT TO THE VENTRAL SITE, WE DON'T SEE ANY PATTERNS OF THE MIGRATION OF THE INTERNEURONS, SO ONE OF THE THINGS IN THE FIELD IS THE RANDOM DISTRIBUTION OF SO MANY DIFFERENT TYPES OF INTERNEURONS IN THE CORTEX AND STILL WE CAN GENERATE ORGANIZED COLONIC CIRCUITING IN IT THE CORTEX AND THIS IS A BIG CONUNDRUM IN THE FIELD, OUR FIELD HAS MUCH MORE BROAD ACTIVITY THAN THE REGULAR NEURONS BUT WE STILL HAVE ORGANIZATION, FOR EXAMPLE, THIS IS WORK DONE BY GAYLE MISSENBOCK'S GROUP. WE FOUND SITTING IN A DIFFERENT BARRELL THEY RECEIVE DIFFERENT INPUT, INHIBITORY INPUT AND THIS BARRELL THEY RECEIVE THE INPUT FROM THIS REGION AND THAL BARRELL THEY RECEIVE A SEPARATE GROUP, SUGGESTING OVERALL VERTICAL ORGANIZATION IN THE CORTEX, SO WE START TO WONDER IN LIMITED INDEPENDENT ORGANIZATION OF THE INTERNEURONS TO SOME DEGREE, TO THE EXCITATORY NEURONS IN THE CORTEX BUT THIS IS CHALLENGING BECAUSE IT'S VERY DIFFICULT TO LABEL THOSE INTERNEURON PROGENITOR CELLS IN THE PERFORM THOSE BECAUSE THEY'RE VERY SMALL POCKET OF THE PROGENITOR CELLS AND YOU PUT THOSE IN THE VENTRILE AND MOST'VE THOSE ARE THE PROGENITOR BUT YOU KNOW THAT THE PIE O NEAR WORK DONE BY MANY GROUPS, WITH THE TRANSCRIPTION PROGRAM OF THOSE VENTRAL M. D. THEY EXPRESS 2.1, YOU ACTUALLY CAN MAKE THIS AND CREE MICE TO LABEL THOSE PROGENITOR CELLS THAT PRODUCE THE INTERNEURONS AND THE CORTEX, SOPHISTICATEDY WE COMBINE THIS TYPE OF GENETIC MAPPING WITH ONE OF THE RETROVIRUS LABELING AND TO THE SPECIFIC LABEL FOR THOSE CELLS FOR THE IRPT NEURON. THIS IS NOT TYPICALLY EXPRESSING THE CELLS BUT WE CAN USE THE FOR A RECEPTOR ONLY IN THOSE PROGENITOR CELLS IN THIS [INDISCERNIBLE] TRANSCRIPTION FACTORS. SO IN OTHER WORDS WE MAKE THIS CROSS BETWEEN THIS CREE LINE VERSES CONDITIONAL ALLELE OF THE TB AND WE CAN DRIVE THE EXPRESSION HERE ONLY IN THOSE MD PROGENITORS, AND THEN WE GET RETROVIRUS TO THE CLASSIC LNG OVER THOSE PROGENITOR CELLS FOR THE FIRST TIME WITH THE SPACIAL TEMPRICITY. SO THIS IS INDICATED OF THE TB RECEPTOR AND YOU HIT THE VIRUS OF E12 BECAUSE IT'S ONLY THE CELL LABELED IN THIS, WITHIN AN MD PERIOD, YOU CAN PRODUCE A LOT OF DAUGHTER CELLS THAT MIGRATE THROUGH THE CORTEX AND THIS ROUND OF INJECTION, THERE'S NEURONS IN THE CORTEX AND HIPPOCAMPUS AND THOSE ARE THE IRONS. WELL WE FIND THAT THE BEHAVIOR OF THE CELLS AND PREOPTIC AREA, AND EMBRYONIC STAGE IT'S SIMILAR TO THE PROGENITOR CELLS AND WE HAVE THIS GLIAL PROCESS, I'M NOT SURE WE CAN SEE IT AND THEY PRODUCE CELLS AND THEY'RE ALWAYS VERY CLOSE, ASSOCIATE WIDE THE RADIAL GLUEYA TO FIND THIS RADIO UNIT. AND WE CONFIRM THAT THEY'RE DIFFERENT COLORED VIRUS, AND YOU CAN SEE THE REGGREGATION BETWEEN THIS SUGSCWHEOF THING THAT THEY COME FROM A STINGLE DIVIDING RADIO GLIAL PROGENITOR CELLS AND FROM THIS VERTICAL CLUSTER EXCITATORY NEURONS AND WE DO DURING THE PRODUCTION PHASE, WE DO THE CLUSTER BUT THOSE ARE VERY LONG TANGENTIAL MIGRATION FROM THE REGIONAL CORTEX IF WE USE SIMILAR TECHNOLOGY, THEY CAN LABEL THE CLONES OF EXCITATORY NEURONS AND THE MANY GROUPS OF EXAMPLE EARLY DAYS, BUT WHAT HAPPEN FEDERAL WE DO THE SIMILAR APPROACH FOR THE INTERNEURONS TO SEE WHEN THEY FINISH THE MIGRATION OF THE CORTEX, DO THEY RANDOMLY DISTRIBUTE OR DO THEY FORM SOME TYPE OF ORGANIZATION, ONCE WE MARK THEM WE SEE THAT'S THEY DO FORM THE CLUSTER AS SHOWN HERE AND THE INTERNEURONS, AGAIN ALSO SEE THE HORIZONTAL CLUSTERS, IN FACT, THIS IS QUITE ABUNDANT, BEING LABELED AT THIS TIME POINT AND LOOK AT PSEVEN AND YOU CAN SEE THAT P21 AND MOST OF THE INTERNEURONS ARE MATURE, CAN YOU STILL SEE THIS CLUSTER ABOUT 50% OF THOSE CELLS CAN BE FOUND AND THEY CAN BE EITHER VERTICAL OR HORIZONTAL CLUSTERS. SO DO WE THINK THAT PRODUCTION OF INTERNEURONS IN THE VENTRAL MG OR WE ALSO HAVE THIS ORGANIZED BEHAVIOR, AND IT GOES TO CELL DIVISION TO PRODUCE A CLUSTER AND THOSE NEURONS GOES THROUGH THE TANGENTIAL MIGRATION, IT STARTS TO MIGRATE THE CORTEX AND WHEN THEY FINISH THEIR MIGRATION IN THE TORTEX WE LABEL THOSE PROGENITOR CELLS YOU HAVE TO CLONE UPWARD YOU CAN SEE THE VERTICAL-HORIZONTAL CLUSTER ALMOST SIMILAR FASHION AS EXCITATORY NEURONS [INDISCERNIBLE] EXCITATORY NEURONS AND ALSO BEING FORMED BY OSCAR MARIN'S LAB, BUT YOU MAY HAVE SEEN A RECENT STORY WHEN WHERE THEY ARGUE THERE'S THERE BROAD DISPERSION OF CLONAL RELATED INTERNEURONS HAVE A LONG TANGENTIAL DISPERSION IN THE CORTEX. I WOULD LIKE TO PRECEPT TO YOU SOME EVIDENCE, ACTUALLY ARGUE THERE IS LEUCO[INDISCERNIBLE] FOR EXAMPLE IF YOU LOOK AT THE INTERMUNICIPALONAL AFTER [INDISCERNIBLE] OF DIFFERENT BRAIN REGS YOU CAN FIND MORE THAN 70% OF THOSE CLONES, THEY RECOVERED, ACTUALLY THEY'RE IN THE SAME STRUCTURE AND MOSTLY IN THE CORTEX, AND THE SECOND CLASS IS THE HIPPOCAMPUS ABOUT 21%, THOSE ARE THE HIGHLY TWO RELATED REGIONS, AND CONTINUED STRUCTURE SUGGESTING THAT THE VAST MAJORITY OF THE CLONE, NOT SPARED ACROSS DIFFERENT BRAIN STRUCTURE AND THE VAST MAJORITY OF THE CORTEX OR CORTEX IN THE HIPPOCAMPUS FROM THE STRUCTURE, ONLY A MINORITY OF THE CLONE SPARING DIFFERENT BRAIN STRUCTURE FOR EXAMPLE, THE CORTEX AND THE STRIATUM, THE INTERNEURON FROM THE LOCAL CLUSTERS AND THIS IS BASED ON INITIAL DENDRITIC CELL ROW GRAM, ENG THIS, ALL CLONES FROM A LEUCOCLUSTER AND THIS IS THE DENDRITIC CELL ROW GRAM, LOOKING AT THE HIERARCHY OF THE DISTANCE BETWEEN ALL THE LABEL ITSELF, SO THE BECAME BACHHOLD IS A NUMBER THERE, FOR EXAMPLE, THOSE ARE THE SAME CLONE AND THIS IS 26 IS ANOTHER CLONE. WE CAN SEE THERE'S A LABELED FEATURE OF THE CLUSTER CAN BE CLONAL RELATED AND THIS IS FAR FROM RANDOM, FOR EXAMPLE, MORE THAN 65% OF THE [INDISCERNIBLE] INTERNEURON CLUSTER ARE CLONAL RELATED AND IF YOU LOOK AT I CLONE MORE THAN--CLOSE TO 50% OF GROWNAL INTERRELATED NEURONS FORM A CLUSTER AND IN FACT, THIS MEASUREMENT IS NOT THE MOST ACCURATE MEASUREMENT BECAUSE CLUSTERING DOESN'T REALLY MEAN IT'S A SHORT DISTANCE BETWEEN TWO CELLS, THAT REFLECT TO THE RANDOM DISPERSION, SO THERE'S ADDITIONAL [INDISCERNIBLE] HAVE TO BE PERFORMED ON THOSE DATA AND THAT SHOULD GIVE YOU SINGLE CELL RESOLUTION OF THE CLONAL IDENTITY. AND THE THIS IS ANOTHER GROUP. IN THIS TYPE, ONLY HAVE ONE BRAIN, CAN YOU STILL SEE BETWEEN THE CLONAL LABELING INTERNEURONS AND RANDOM DISTRIBUTED CELLS YOU CAN SEE IT'S SHORT SHIFTED MEANING THE CLONAL LABELS ARE MORE CLUSTERED THAN RANDOM CELLS AND THIS ANNALIZES ALL THE SINGLE CELLS SO--THIS HAS TO ANALYZE TO TEASE THIS PART. BUT I WOULD LIKE TO MENTION THAT THER ACTIVE DISCUSSIONS TO TAKE THIS PRECIOUS DATA SET TO ALLOW A MUCH HIGHER RESOLUTION OVER THE CLONAL DISTRIBUTION IN HAD THE CORTEX IN TERMS OF INTERNEURONS, AND DIFFICULT GROUP OF NEURONS TO START IT. SO HERE, I LIKE TO EMPHASIZE WE THINK THAT INTER NEURORGANIZATION TO SUBSTANTIAL PROPERTY OF THOSE CLONAL THEY DO FORM CLUSTERING IN A WAY, AND THE QUESTION IS IN THE FUNCTIONAL WAY CAN WE DETECT IT SO THIS IS THIS IS A QUESTION WHEN WHETHER WE CAN DETECT THIS CLUSTER IN THE CORTEX IN TERMS OF THEIR CONNECTIVITY. WHAT WE FIND IS THAT THE WE FIND IT MUCH HIGHER CONNECTIVITY IN TERMS OF THE INFORMATION BETWEEN RELATED INTERNEURONS ACROSSS IT HERE AND YOU WILL DOUBLE THE AMOUNT OF SYNAPSE BETWEEN THE FORM AND THE INTERNEURON CLUSTER AND THIS IS QUITE IMPORTANT FOR THE COMMUNICATION BETWEEN INTERNEURONS AND WHAT WE FIND IS THAT IF THERE'S A SISTER CELL, THAT CAN FORM AGAINST EACH OTHER AND THERE'S MUCH HIGHER TERMS WITH SISTER CELLS, AND THEY MAKE THE SYNAPSE TO THE SAME TARGET OF THE NEURONS SUGGESTING THIS COORDINATE, AND DEPENDS ON THE IMAGINGLY RELATIONSHIP AND THE JUNCTURE AND SUGGIEST THIS DEPENDENT FUNCTIONAL ORGANIZATION OF THE CLUOF THEDDER AND THE CORTEX. SO I'D LIKE TO END BY SAYING THAT WE FIND THE CORTEX IN THE HIPPOCAUS THERE'S STRONG INFLUENCE OF EARLY PROCESS NEUROGENESIS AND MIGRATION IN TERMS OF THE ORGANIZATION OF THE CIRC ULTIMATELY OPERATION OF THE BRAIN STRUCTURE. FOR EXAMPLE WE CAN FIND INDIVIDUAL FORM, THERE'S A CHEMICAL SYNAPSE FORMATION IN THE INDIVIDUAL CLONE TO SHARE PHYSICAL PROPERTIES AND WE CAN ALSO SEE THE FORM BUT THEY DO NOT FORM A VERTICAL CLONE BUT YOU SHOULD FORM A HORIZONTAL CLONE BUT THEY RECEIVE INHIBITOR INPUT AND ANOTHER CLONE TO BE SYNCHRONIZED AND WE HAVE A FEAT IRB OF THE HIPPOCAMPUS FOR A DYNAMIC STRUCTURE IN TERMS OF THEIR ORGANIZATION. SO I'D LIKE TO END BY SPECULATING A BIT OF WHAT WE HAVE DONE IN THE MICE, WITH THIS IMPLICATION FOR OTHER SPECIES, ESPECIALLY FOR EXAMPLE, WE THINK ABOUT PRIMATE OR HUMAN, THERE'S THIS IDEA THAT THE THERE'S A GREAT EXPANSION OF THE CORTICAL FROM THE MOUSE TO HUMAN AND THIS IS BECAUSE OF THIS PROGENITOR CELL AND EXPANSION, AND THE PROGENITOR CELLS PRODUCE MORE SETS OF EXCITATORY NEURONS AND THE HIGH MAMMALS BECAUSE YOU HAVE THE PROGENITOR CELLS AND THE PROGENITOR, [INDISCERNIBLE] SO BECAUSE OF THIS AMPPLIFICATION AT THE SUBVENTRICAL ZONE, YOU CAN PRODUCE MUCH LARGER, NEURONAL OUTPUT AND PRODUCE MUCH LARGER CLONE. SO IF THERE'S A ENERGY DEPENDENT ORGANIZATION, THERE'S EXPECT OVER ALL ORGANIZATION OF FUNCTIONAL MAPPING OF THE CORTEX WOULD BE SLIGHTLY DIFFERENT AND IN FACT, THIS IS EXACTLY WHAT WE SEE. IF WE COMPARE THE VISUAL CORTICAL MAP IN THE VISUALLY CORRECT IN TERMS OF THE ORIENTATION SYNAPTIC YOU CAN SEE A DIFFERENCE BETWEEN THE RAT AND THE CAT AND YOU HAVE THIS SALT AND PEPPER PATTERN WHICH MEANS THE LABELING NEURONS HAVE DISTIRCHGHT ORIENTATION PROPERTY BUT IF YOU LOOK AT THE CAT, YOU CAN SEE THE SAME ORIENTATION CLUSTER TOGETHER AND WE CALL THIS FUNCTIONAL MAP SO MAYBE THIS TYPE OF DIFFERENCE IN TERMS OF THE FUNCTIONAL ORGANIZATION MAYBE RELATES TO THE EARLY EMBRYONIC PROCESSING IN TERMS OF NEUROGENESIS AND THE PROGENITORS CAN PRODUCE A LARGE COHORT OF NEURONS AND A MAIN ORGANIZATION OF THE CORTEX WHICH IS A VERY INTERESTING QUESTION WE'D LIKE TO TEST. SO I'D LIKE TO END BY [INDISCERNIBLE] THANKING PEOPLE FOR THEIR WORK. SO THE ENI SHALY BY POST DOC ZHIZHONG LI, AND EVERYBODY IN THE LAB AND THIS IS CLOSE COLLABORATION WITH POST DOCS AND BEN SIMONS WHO HAVE DONE SOME MODELING OF THE PROGENITOR CELLS AND THOSE ARE THE FUNDING, WE GOT SUBSTANTIAL FUND FREE RADICALS GENERATED NIH. THANK YOU VERY MUCH FOR YOUR ATTENTION. [ APPLAUSE ] >> [INAUDIBLE QUESTION FROM AUDIENCE ] >> THIS IS A GREAT QUESTION SO WE DON'T HAVE DIRECT EVIDENCE, CYTOPLASTIC BRIDGE BEING MAINTAINED BECAUSE THE NUCLEI WILL COME DOWN AND ENLARGE AND THEY WILL HAPPEN FROM THE BASAL SIDE TO THE AND THEN THEY WILL HAVE TO MOVE, SO IN OTHER WORDS, IF THERE'S A BRIDGE LEFT, THAT BRIDGE HAS TO BE DYNAMICALLY, YEAH. >> THEY HAVE TO, SO IN FACT, THE JUNCTION HAS BEEN DETECTED BETWEEN THE PROPREENITTOR CELLS BETWEEN NEURONS OR MIGRATING CLLS AND JUNCTION NEURONIC ALLOWS ELECTRIC COMMUNICATION BUT ALSO IT'S A VERY ADHESIVE FORCE, SO BEING SUGGESTED IMPORTANT FOR RADIAL MIGRATION FOR SLIDING OF THE CELLS, SO IN THAT SENSE THEY COULD HAVE THE GAP JUNCTION REMINISCENT BEING LEFT FROM THE PROGENITOR CELL STAGE BUT ALSO ONE OF THE THINGS THAT WE CAN RARELY DETECT PROGENITOR CELLS, IS VERY DISTANT CELL, STILL MAINTAIN COUPLE BECAUSE THERE COULD BE TECHNICAL PROBLEM BECAUSE JO GENITOR CELLS VERY TRICKY IN TERMS OF CURRENT DETECTION BUT WE CANNOT RULE OUT SOMETHING COME FROM VERY BEGINNING RELATES TO HOW TO DAUGHTER CELL BEING PRODUCED. >> [INAUDIBLE QUESTION FROM AUDIENCE ] >> YEAH, SO I CAN ONLY SPECULATE ABOUT EARLY STUDIES, I MEAN THERE'S NOT SO MUCH--VERY [INDISCERNIBLE] 80S, 90S THERE WAS DEBATE IN TERMS OF TANGENTIAL DISPERSION [INDISCERNIBLE] WITH THE DATA ARE MOSTLY CONNECTED BEFORE WE KNOW INTERNEURONS COME FROM VENTURE SO I THINK SOME CONTRIBUTION OF THIS TANGENTIAL IS THAT THE IDEA IS THAT WE PUT IN THEET RETROVIRUS AND WE LABEL THE CELLS AND WE HAVE NEURONS BEEN LABELED AND WE CAN PROBE THEIR RELATIONSHIP BASED ON THE RETROVIRUS TAG. THERE WAS DEBATE ABOUT WHETHER THE INDIVIDUAL TAG IS UNIQUE AND ALSO INFECTING THE EARLY DAYS THEY CAN DETECT AND THEY WERE BOTH INHIBITOR CELLS AND EXCITATORY CELLS THAT SUGGEST THAT THE TAG IS NOT UNIQUE IN THE SINGLE PHASE. SO THAT CONTRIBUTE TO SOME OF THOSE DEBATE AND ALSO IMAGING SHOW TANGENTIAL NEURONS AND THOSE COME FROM INTERNEURONS BECAUSE THOSE COME FROM TANGENTIAL DISPERSION SO I THINK SOME OF THE--YOU KNOW PROBLEM IS UNDERSTANDING IS BECAUSE OF THE GROUPING TOGETHER BETWEEN RADIO MIGRATION OF EXCITATORY CELLS AND TANGENTIAL MIGRATION OF THE CELLS BUT I DON'T KNOW THAT'S MY SPECULATION IN TERMS OF TANGENTIAL DISPERSION BECAUSE IN OUR DATA WE FIND VERY LITTLE [INDISCERNIBLE] TAMPLEGGENTIAL BUT OF COURSE WE CANNOT SAY THE SAME VERY--SINGLE STRAIN SO THERE'S SOME DISPERSION MOSTLY FOR THE [INDISCERNIBLE], I DIDN'T SHOW HERE, IN TERMS OF AREA DIFFERENCE, THE MAJOR AREA HAVE TANGENTIAL DISPERSION WHERE CORTEX MAKE THE BEND IN THE ANTERIOR [INDISCERNIBLE] CORTEX AREA, WILL THE CORTEX BEND, THERE THE SUPERFICIAL CELLS ARE MUCH MORE DISPERSES BUT THEY STILL FORM A GROUP. THEY DON'T HAVE A LONG RANGE DISPERSION SO WE THINK THAT DISPERSION IS BECAUSE WHEN THE RADIAL GLIAL CELLS REACH THE PEER SURFACE IT'S GROWING WHERE THEY FINISH THE MIGRATION, ARE THE CELL DETACHED FROM THE OTHER RADIAL GLIAL, AND THEY CAN BE DISPURSED AS A CORTICAL EXPAND, SO THERE'S AREA DIFFERENCE BUT THOSE ARE THE SUBTLE DIFFERENCES. >> DO HAVE YOU AN IDEA WHY [INAUDIBLE QUESTION FROM AUDIENCE ] >> YEAH, I DON'T HAVE ANY DIRECT ANSWER BECAUSE IT IS HARD TO KNOW HOW THEY MAINTAIN A CLOSE RELATIONSHIP THROUGHOUT THIS ENTIRE PROCESS BECAUSE MIGRATION OF INTERNEURONS WILL TAKE A WEEK FROM THE BIRTH TO THE FINAL DESTINATION. SO, WE HOPE TO DO TIME LAPSE IMAGERY AND MAP THEM OUT BUT WE HOPE THERE'S SOME CODING BETWEEN TWO DAUGHTER CELLS DIVIDING CELLS, THEY CAN MIGRATE IN DIFFERENT DIRECTION BUT THEY MAY HAVE COLONIZATION IS MADE BY CONTACT OR CHEMICAL SIGNALS THAT'S SOMETHING WE DON'T KNOW THAT'S A QUESTION WE WOULD LIKE TO LOOK INTO MORE. >> SO I'M WONDER WHAT DO YOU THINK THE CLONAL DISTRIBUTION [INAUDIBLE QUESTION FROM AUDIENCE ]-- >> YEAH THIS IS A GREAT QUESTION. WE ACTUALLY ARE COLLABORATING WITH SOMEONE TO SIMULATE WHAT WE DID IN THE VISUAL CORTEX TO SEE TPHAOEUGZINIZEATION--ORGANIZATIO N THE INDIVIDUAL CLONE HAVE DEFINED PHYSIOLOGICAL [INDISCERNIBLE] IN THE OF COURSE PLACE WE KNOW THE MOST SO THE QUESTION IS IF WE PUT THE MICE IN A RUNNING TRUCK THEN WHY LABEL INDIVIDUAL CLONES CAN WE IMAGE CALCIUM SIGNAL AS THE ANIMAL SO I HOPE I CAN TELL YOU IT'S A BIT [INDISCERNIBLE]. >> [INDISCERNIBLE] >> CAN YOU SAY IT AGAIN? >> [INDISCERNIBLE] >> YEAH, THAT'S A GOOD--BECAUSE THE CELLS DO HAVE ACTIVITIES INITIALLY SIRCHG RONNIZED BUT MATURE AND BECOME [INDISCERNIBLE] BUT WE HAVEN'T LOOKED DIRECTLY AT THE INDIVIDUAL CLONAL LABEL, WHAT IS THE PRECISE ACTIVITY PATTERNS AND HOW DOES THAT, YOU KNOW PROCEED. >> [INDISCERNIBLE]. >> YEAH WE HAVEN'T LOOKED INTO THAT AND THERE'S ALWAYS SOME IDEAS JUST AS A CALCIUM WAVE AND GLUTAMATE RECEPTOR OR SOME RECEPTORS ARE INVOLVED IN A RINK RONNIZED OR ORGANIZATIONSIZE DOMAIN BUT WE HAVEN'T LOOKED AT INDIVIDUAL CLONAL. YES? >> KD--SALLY [INAUDIBLE QUESTION FROM AUDIENCE ] >> [INAUDIBLE QUESTION FROM AUDIENCE ] >> YEAH, SO, OVERALL, YOU KNOW WAVE OF NEOGENESIS SO WE KNOW THAT FOR EXAMPLE, VENTRALNY O GENESIS HAPPENED EARLIER SO THIS WAVE FROM THE VENTRAL TO DORSAL PROBABLY NATURAL TO MEDIAL WAVE OFNY O GENESIS BUT THE SIZE OF UNIT, FOR EXAMPLE, THE NEOGENESIS, THAT'S IN THE INTERCORTICAL AREA, THERE'S NO FUNDAMENTAL DIFFERENCES SO THEY MAY ENTER THE PROGRAM AT DIFFERENT TIME BUT THE PROGRAM IS VERY MUCH COMPARABLE. AND ALSO THIS RAISES A VERY INTERESTING QUESTION AS HERE I EMPHASIZED ALMOST EXCLUSIVE ON THE SIMILARITY OF INDIVIDUAL CLONES BUT CAN YOU SEE, WE RARELY CAN SEE TWO CLONES ARE THE SAME IN TERMS OF THE NUMBER OF CELLS, IN TERPS OF THE DISTRIBUTION, DIFFERENT LAMINAS, THAT WE CONTINUE TO DIGEST, FOR EXAMPLE, THE CERTAIN CORTICAL AREA [INDISCERNIBLE] SO THEY MUST HAVE SOME LOCAL [INDISCERNIBLE] PROGENITOR CELL TO PRODUCE THE TEMPLATE OF THE CORTEX WHICH FITS ITS FUNCTION AND THAT WILL TAKE US A LONG TIME TO DIGEST THE LOCAL, FOR EXAMPLE WE DON'T EXPECT THE PROGENITOR CELLS BUT THE SAME TIME WE DO THE SAME BUT THE OLL BEHAVIOR LOOKS QUITE ORGANIZED BUT IT'S TIME TO SEE THE INDIVIDUAL CORTICAL AREA, TO DISSECT AND PRODUCE A RANDOM COMBINATION OF CELLS OR THEY ACTUALLY ROUGH ATOM DUCE A DEFINED ORGANIZATION OR PATTERN OF THE CELL TYPES. IN THE CORTEX. THANK [ APPLAUSE ] YOU VERY MUCH. [ APPLAUSE ] .