WELCOME TODAY'S SPEAKER, BEATRIZ RICO, COMES FROM THE MRC CENTER FOR NEURO DEVELOPMENTAL DISORDERS. SHE DID A POSTDOC AT CALIFORNIA SAN FRANCISCO. SHE THEN MOVED BACK TO SPAIN TO GO TO THE UNIVERSITY IN ALICANTE WHERE SHE QUICKLY ROSE UP THE RANKS TO BECOME PROFESSOR. SHE'S DONE JUST INCREDIBLE WORK DURING HER TENURE TRACK PERIOD AND RECENTLY IN THE LAST COUPLE YEARS, SHE'S MOVED TO KINGS COLLEGE, LONDON, AND CULTURE SHOCK CALLED SNOW, NOT SPAIN. BUT NEEDLESS TO SAY, SHE'S CARRIED ON DOING TREMENDOUS WORK AND I THINK THAT YOU'LL SEE ONE OF THE THINGS THAT I'VE ALWAYS BEEN IMPRESS BID BEATRIZ' WORK IS IT'S BEEN PUNCTUATED BY JUST A HIGH QUALITY NUMBER OF PAPERS OVER THE YEARS THAT HAVE REALLY BROUGHT CLARITY TO VERY DIFFICULT QUESTIONS. OF COURSE BEATRIZ AS YOU'LL SEE IS INTERESTED IN CORTICAL NEURON AND CIRCUIT DEVELOPMENT WITH AN EMPHASIS ON GABAERGIC INHIB ARE TORE INHIBITOR NEURONS, PARTICULAR EMPHASIS ON SCHIZOPHRENIA, SO I'M NOT GOING TO TAKE ANY MORE TIME BUT I'D LIKE YOU TO WELCOME BEATRIZ AND SHE'S GOING TO TALK ABOUT BUILDING CORTICAL NETWORKS FROM MOLECULES TO FUNCTION. SO BEATRIZ, WELCOME. >> SO CAN YOU HEAR ME FROM THE BACK? YES? OKAY. SO OOO I'D LIKE I'D LIKE TO START THIS PRESENTATION BY THANKING CHRIS FOR ASKING ME TO PRESENT HERE, ALL THE WORK WE'VE BEEN DOING THE LAST YEARS IN THE LAB AND RECENT WORK THAT WE'VE ALSO BEEN DOING. I AM VERY HAPPY TO BE INTERACTIVE SO ANY TIME YOU DON'T UNDERSTAND ANYTHING, JUST FEEL FREE TO ASK ME ANY QUESTIONS THAT YOU THINK THAT IS -- YOU NEED TO ASK, NO MATTER -- YOU MIGHT THINK IT'S A STUPID QUESTION, AND IT'S NEVER A STUPID QUESTION. SOMETIMES IT'S OUR FAULT THAT WE DON'T REALLY EXPLAIN OURSELVES WELL. SO I'M GOING TO START MY PRESENTATION TO SHOW YOU THIS VIDEO. >> I WILL LET YOU KNOW, BASICALLY THIS IS AN INTERACTIVE VIDEO, THIS IS SHOWING HOW A LITTLE BABY WAS INTERACTING WITH HER MOTHER. I LIKE TO SHOW HOW WE INTERACT WITH THE ENVIRONMENT, BASICALLY THIS VIDEO WAS SHOWING HOW DIFFERENT WE, THE HUMANS, WE HAVE DIFFERENT BEHAVIOR, THIS IS HAPPENING IN DIFFERENT SPECIES. I JUST WANTED TO SHOW HOW DIFFERENT BEHAVIORS ARE VERY DIVERSE, WE HAVE TO SOMEHOW FACE DIFFERENT SITUATIONS THAT WE HAVE TO, AND FOR ALL THIS HAPPENING, IT'S IMPORTANT THAT WE HAVE VERY PRECISE CONNECTIVITY BETWEEN DIFFERENT NEURONS IN THE BRAIN, AND THIS PRECISE AND FINE-TUNED CONNECTIVITY IS WITH THE HIGHEST COMPLEXITY PRECISELY IN THE CEREBRAL CORE TECH, WHERE YOU CORTEX, MANY PEOPLE HERE WORK IN CORE CORTEX, MAXIMUM COMPLEXITY REFLECTED BY THE INTERACTIONS BETWEEN TWO MAIN POPULATION OF NEURONS. THE INTERNEURONS HAVE VARIOUS -- BUT IN SPITE OF THAT, FINE-TUNE AND FACE THE RHYTHMS OF THE CELLS. I ALWAYS LIKE TO BRING THIS CARTOON, WHAT IS THE WAY THAT NOT ONLY ME IN THE FIELD, MANY PEOPLE IN THE FIELD OF INTERNEURONS SEE HOW THE INTERNEURONS WORK. BASICALLY EVERYBODY IN THIS ROOM ROOM -- HOW TO PLAY THE DIFFERENT INSTRUMENTS, THE VIOLIN, THE DRUMS, BUT WITHOUT A CONDUCTOR, WE WILL NOT BE ABLE TO HAVE THE EMERGENCE OF THIS BEAUTIFUL SIM KNOW SYMPHONY THAT THE CONDUCTORS MAKE HAPPEN, SO THEY ARE ABLE TO SYNCHRONIZE ALL THE SOUNDS THAT ARE COMING FROM THESE INSTRUMENTS AND MAKE POSSIBLE TO HEAR AND TO LISTEN TO THIS BEAUTIFUL SYMPHONIES THAT WE LIKE TO HEAR EVERY TIME WE GO TO THE ORCHESTRA. AND I THINK THAT PRECISELY THIS IS THE WORK THAT THE INTERNEURONS DO IN THE CORTEX. THEY ARE ABLE TO ORCHESTRATE THE FUNCTION OF THE CELLS AND WE CAN DISCUSS ABOUT THAT LATER ON. WHAT HAPPENS WHERE DURING DEVELOPMENT, ALL THESE INTEGRATIONS BETWEEN THE INTERNEURONS AND THE -- FAILS SO YOU NOW WE HAVE MANY EVIDENCE SUGGESTING THAT UNDERLYING THIS, MANY OF THE MOST DRAMATIC DEVELOPMENT -- SCHIZOPHRENIA TO EPILEPSY, THERE IS AN IMBALANCE BETWEEN INHIBITION AND ECK SIGH TAIG. EXCITATION. WHAT IS THE PATHOPHYSIOLOGY OF THESE DISORDERS, WE HAVE -- THAT IS POINTING OUT IN SCHIZOPHRENIA AND WE -- BUT MY TALK IS GOING TO BE BASED ON THE THREE MAIN ASPECTS THAT MY LAB IS WORKING ON. MY LAB, WE ARE TRYING TO UNDERSTAND HOW ARE THE MAMMALIAN CORTICAL NETWORKS BUILT AND I'M GOING TO BRIEFLY COMMENT ON THAT BECAUSE I THOUGHT THAT PEOPLE IN THIS AUDIENCE WILL BE MORE INTERESTED IN ABOUT THE FACILITY OF THE CORTICAL CIRCUITRIES. THE SECOND QUESTION IS THAT MY LAB IS INTERESTED IN TRYING TO UNDERSTAND HOW THESE CIRCUITRIES RESPOND TO ACTIVITY, AND THEN THE LAST QUESTION THAT WE'RE TRYING TO ADDRESS IS THAT WHAT IS THE FUNCTIONAL CONSEQUENCE OF WHEN THIS IS SOMEHOW DISRUPTED DURING DEVELOPMENT. GOING TO THE FIRST QUESTION, WHAT WE HAVE BEEN TRYING TO UNDERSTAND, ONE OF OUR MAIN QUESTIONS IN THE LAB IN THE LAST FOUR YEARS IS THAT HOW THESE INTERNEURONS MAKE SPECIFIC SYNAPSIS -- WE THIS THIS IS THE RELEVANT QUESTION BECAUSE YOU CAN THINK THAT IT'S NOT THE SAME HOW THESE -- CELLS ARE -- DENDRITES OF THE PEER PYRAMIDAL CELLS -- SOMEHOW TARGET THE SOMA. SO HOW THESE INTERNEURONS ARE SOMEHOW CONTROLLING THE OUTPUT OF THESE PYRAMIDAL CELLS WILL BE DIFFERENT DEPENDING ON HOW IT'S WORKING. WE'RE TRYING TO UNDERSTAND WHAT IS THE MOLECULAR SIGNATURE THAT THESE INTERNEURONS ARE USING FOR BRAIN DEVELOPMENT. THIS IS WORK THAT HAS BEEN DONE IN THE LAB BY DIFFERENT PEOPLE. THIS IS THE WORK OF -- BASICALLY THE SPECIFIC QUESTIONS THAT WE TRIED TO ADDRESS WAS, OKAY, IF WE WANT TO KNOW HOW THESE INTERNEURONS ASSEMBLE, WE CAN HAVE A FIXED PICTURE OF THE SNAPSHOT -- PARTICULAR GENE OR PARTICULAR CELL OF GENES. WHAT WE REALLY NEED TO KNOW IS ONE OF THE SIGNATURES OF THE MOLECULAR PROGRAM OF THESE INTERNEURONS BY THE TIME THAT THESE INTERNEURONS ARE DOING THE WRITING. AND TO ANSWER THIS QUESTION, SO WE'RE TRYING TO UNDERSTAND WHEN THESE INTERNEURONS ARE MAKING SYNAPSES, WHAT IS THE -- ARE EXPRESSING. TO ANSWER THIS QUESTION, WHAT WE DID FIRST IS TO TRY TO UNDERSTAND HOW THESE INTERNEURONS MAKE SYNAPSES DURING DEVELOPMENT AND WE FOCUSED ON HOW THESE UNIT NEURONS SEND THE INPUTS TO THEIR TARGETS AND THIS IS FOR THE -- CELLS AND WHAT WE FOUND USING DIFFERENT MARKERS IS THAT THE WAY THESE INTERNEURONS MAKE SYNAPSES, THERE'S A TIME WINDOW OF THESE INTERNEURONS, THERE IS DIFFERENCE A. DIFFERENCE BETWEEN DIFFERENT INTERNEURONS, BUT WHAT WAS COMMON BETWEEN THESE THREE POPULATIONS OF INTERNEURONS IS PRECISELY THIS TIME POINT, BETWEEN P5 AND P10, SO ALL INTERNEURONS HAVE AN INCREASED -- ON THIS PRECISE DYNAMIC POINT. SO WE HAVE A TIME POINT WHICH SEEMS TO BE A CRITICAL TIME POINT THAT THESE INTERNEURONS ARE MAKING SYNAPSES, SO WE ASKED THE QUESTION WHAT IS HAPPENING AT THIS POINT? SO HOW IS THE DYNAMIC, THE TRANSCRIPTIONAL DYNAMIC IN THESE INTERNEURONS BY THE TIME THAT THESE INTERNEURONS ARE MAKING SYNAPSES. AND A I I'M NOT GOING TO GO INTO DETAILS ON THIS PROJECT, BUT BASICALLY WE USE DIFFERENT REPORTER LINES TO SORT INTERNEURONS THAT WERE -- THAT THESE INTERNEURONS WOULD ENCRYPT IN, WE SORTED AND DID SEQUENCING TO SOMEHOW UNDERSTAND HOW IS THIS SIGNATURE. JUST AS AN EXAMPLE, WHAT WE COULD FIND THERE IS WE HAVE -- TRANSCRIPTOME SIGNATURE IN THE -- CELLS COMPARING WITH THE CELLS. THIS WE CAN DISCUSS LATER, BUT I THINK THAT I WILL MOVE TO THE FEX PROJECT IN WHICH I HOPE THAT YOU WILL -- SOMEHOW YOU WILL LEAVE MORE ENGAGED. SO THE QUESTION WE'RE TRYING TO ADDRESS HERE IS THAT OKAY, HOW THESE INTERNEURONS RESPOND TO THE ACTIVITY TO THE ENVIRONMENT. AND WE FOCUSED IN THE -- CELL POPULATION BECAUSE IT'S MAJORITY OF THE INTERNEURONS, AND ALSO BECAUSE ALONG OUR DAY LIFE, WE EXPERIENCE DIFFERENT -- SO WE HAVE DIFFERENT EXPERIENCE OF PLASTICITY OF EVENTS, MORE AIDS, THEY AR STILL LEARNING, MY MOTHER USED THE IPOD, NOW -- 76 YEARS OLD AND SENDING ME WHAT'S APP AND FANCY VIDEO SAYING, OKAY, MOM, THAT'S ALL. BUT SINCE LEARNING SHE'S LEARNING THIS AND I AM QUITE IMPRESSED ABOUT THAT. WE LEARN HOW TO RIDE A BIKE, ALSO OUR KIDS LEARN HOW TO DO NEW THINGS AT THE SCHOOL, AND IT'S THE BEAUTY OF LEARNING THAT WE KNOW NOW THAT IT DEPENDS VERY MUCH ON THE BALANCE BETWEEN INHIBITION AND EXCITATION, SOMEHOW THE INTERNEURONS HELPS THERE TO HAVE A DYNAMIC BALANCE TO SOMEHOW SENSE THE NETWORK LEVELS, TRYING IN A WAY TO USE THIS ACTIVITY TO START NEW EVENTS, NEW FINDINGS. SO BASICALLY ONE OF THE NEURONS THAT HAS BEEN LONG TIME SHOWN THAT THEY ALSO HAVE SOMATIC INHIBITION THAT IN A WAY YOU CAN UNDERSTAND HOW POWERFUL COULD BE THE FUNCTION AND THE ACTION OF THESE INTERNEURONS TO THESE PYRAMIDAL CELLS. SOME TIME AGO, THIS -- WAS SHOWN TO HAVE THIS BEAUTIFUL -- AROUND AND -- COMPOUNDED BY DIFFERENT PROTEINS, AND WE'RE PARTICLARLY INTERESTED IN ONE OF THESE -- IT WAS A PROTEIN THAT AMELIA WAS WORKING ON, NOW AT HARVARD, AND BASICALLY WITH AMELIA, BREVICAN ESPECIALLY WAS RESTRICTED TO SOME POPULATION OF NEURONS. SO IT WAS NOT EXPRESSED IN THE OTHER POPULATION OF NEURONS LOCATED IN THE CORTEX. WHAT EMELIA FOUND ALSO IS THAT BREVICAN IS SPECIFICALLY EXPRESSED IN A POPULATION OF -- IN THE ALL ARE THE SAME. THE TWO WERE DISTRIBUTED DIFFERENTLY IN THE POPULATION. WHAT WE SHOW IS THAT THE MOST PREDOMINANT ISOFORM IN THE -- WERE IN BREVICAN 2. THE MAJORITY OF THE CELLS ARE EXPRESSED IN BREVICAN 2. TO SHOW HOW WAS BREVICAN EXPRESSING ALONG DEVELOPMENT, BUT ALSO THE ANTIBODY TO SHOW HOW IS THE PROTEIN EXPRESSION AROUND THESE PAR VAALBUMIN CELLS. BREVICAN IS EXPRESS IN THE SOMA BUT ALSO IN THE DENDRITES OF THE INTERNEURONS. SO WHAT WE KNOW THERE IS ONE OF THE SYNAPSES MORE POPULATED IN THIS AREA IS INDEED THE EXCITABILITY -- BREVICAN WAS EXPRESSED OR HAD VERY GOOD CORRELATION WITH THE -- IN THE SOMA CELLS. WHAT WE SAW IS THAT BREVICAN DOESN'T HAVE A GOOD CO-EXPRESSION WITH INHIBITORY SYNAPSES THAT ARE ALSO PRESENT AROUND THESE PARVALBUMIN INTERNEURONS. BUT WHAT BREVICAN IS EXACTLY EXPRESSED AT THESE SYNAPSES, SO TO ADDRESS THIS QUESTION -- THREE QUARTERS -- MICROSCOPY AND THIS WAS IN COLLABORATION WITH HEIGE EWERS AND CHRISTIAN WINTERFLOOD AND GOOD COLLABORATION WITH EMELLIA AND BASICALLY WHAT HE FOUND WAS -- WE FOUND THAT THIS EXCITABILITY SYNAPSES LABELED WITH -- YOU HAVE HERE -- WHAT WE FOUND IS THAT BREVICAN IS -- THIS IS JUST AN EXAMPLE OF THIS SYNAPSIS, YOU SEE BREVICAN IS IN THE SYNAPSES BUT ALSO LIKE -- WHAT WE SAY IS IT'S LIKE FLANK IN THE SYNAPSES. AND COMING FROM THIS DATA, WE THOUGHT, OKAY, BREVICAN IS EXPRESSED IN A POPULATION OF PARVALBUMIN CELLS, BUT WHAT EXACTLY -- WHAT IS THE FUNCTION& OF BREVICAN AND WHAT EXACTLY IS IDENTIFIED IN BREVICAN. TO DO THAT, WHAT IS THE DIFFERENCE BETWEEN THE BREVICAN -- CELLS AND THE NEGATIVE CELLS. WHAT YOU SEE HERE IS THAT THIS IS THE BREVICAN BOSSTIVE CELLS IN RED, THIS IS THE BREVICAN NEGATIVE CELLS. DIFFERENCE BETWEEN THESE TWO CELLS IS THE BREVICAN POSITIVE CELLS RECEIVE MORE SYNAPSES COMPARED WITH THE BREVICAN NEGATIVE CELLS AND THIS IS QUANTIFIED HERE. SO THESE POSITIVE CELLS HAVE MORE INPUTS. WHEN WE TRY TO UNDERSTAND WHAT ARE THE FEATURES, WHERE THE SIGNATURE OF THESE PARVALBUMIN CELLS THAT EXPRESS BREVICAN, THIS IS WORK DONE BY -- BASICALLY HE -- THESE CELLS -- WITH BREVICAN ANTIBODY, AND ASKED THE QUESTION, WHAT IS THE DIFFERENCE BETWEEN -- PROPERTIES OF THESE CELLS COMPARED TO THESE CELLS THAT EXPRESS BREVICAN. WHAT THEY FOUND IS A VERY CLEAR DIFFERENCE BETWEEN THE TWO. THE BREVICAN POSITIVE CELLS HAVE -- OTHER PARAMETERS, AND HAVE AN INCREASE IN THE MAXIMUM FREQUENCY. IF YOU WANT TO DISCUSS THAT, I CAN GO MORE IN DEPTH HERE, BUT I LIKE ALWAYS TO SUMMARIZE THAT WITH WHAT WE THINK THAT IS THE BREVICAN POSITIVE CELLS COMPARED WITH THE BREVICAN NEGATIVE CELLS. SO BASICALLY BREVICAN POS IF IT CELLS POSITIVE CELLS HAVE MORE SYNAPSES, LESS EXCITABLE, THESE CELLS RECEIVE MANY MORE SYNAPSES BUT THEY NEED MORE SYNAPSES TO BE RECRUITED. BUT ONCE THEY ARE READY TO FIRE -- POTENTIAL, THEY -- VERY FAST CELLS. WE HAVE ALL THESE PICTURES THAT IDENTIFY BREVICAN POSITIVE CELLS THAT IS A TYPE OF PARVALBUMIN CELL, AND THE QUESTION IS THAT WHAT IS THE ROLE OF BREVICAN? IS BREVICAN SOMEHOW IDENTIFIED IN THESE CELLS PLAYING ANY ROLE IN HAVING THIS SIGNATURE WITH THESE CELLS? AND TO ADDRESS THIS QUESTION, WHAT WE DID WAS ADDRESS THE BREVICAN MUTANT THAT IS A MUTANT FOR ALL TYPE OF CELLS. AND WHAT WE DID WAS TO ANALYZE, OKAY, HOW ARE THE SYNAPSES, SO WE KNOW THAT THE BREVICAN POSITIVE CELLS HAVE MORE SYNAPSES. IF WE DON'T HAVE BREVICAN, THERE IS ANY IMPACT IN THE NUMBER OF EXCITABLE SYNAPSES AND THE ANSWER TO THIS QUESTION IS YES, WE HAVE A DECREASE IN THE -- PARVALBUMIN CELLS, WE HAVE THESE THESE -- AND LESS SYNAPSES IS NOT ONLY -- BUT WE PATCH THESE CELLS AND RECORD THE -- AND WE ANALYZE THE FREQUENCY AND WE HAVE A DECREASE IN THE FREQUENCY SO BASICALLY THERE IS A CLEAR PHENOTYPE IN THESE CELLS THAT HAS LESS INPUTS GOING INTO THE SOMA OF THESE PARVALBUMIN CELLS. OKAY? SO HOW ABOUT THE -- PROPERTY, BECAUSE I SHOWED TO YOU THAT THE INTRINSIC PROPERTIES OF -- WERE DIFFERENT THAN BREVICAN NEGATIVE CELLS SO THE QUESTION IS, IS BREVICAN NEEDED FOR HAVING A PARTICULAR SIGNATURE -- PROPERTIES OF THESE CELLS, AND TO ANSWER THIS QUESTION, ANDRE PATCHED THESE CELLS SO -- WITH CONTROL CELLS, THE BREVICAN POSITIVE CELL HAS LESS ACTION POTENTIAL THRESHOLD, ALSO A LOWER LATENCY, AND ALSO IT HAS AIN AN INCREASE IN -- SO I DON'T PRETEND THAT YOU REMEMBER HOW WERE THE OTHERS BREVICAN POSITIVE BREVICAN NEGATIVE BUT I DID THE SUMMARY FOR YOU, WHICH MEANS THAT THE BREVICAN MUTANT CELLS WERE MORE SIMILAR, THEY WERE NOT IDENTICAL, BUT THEY WERE MORE SIMILAR TO THE BREVICAN NEGATIVE CELLS THAN TO THE CONTROL CELLS. THEY HAVE LESS SYNAPSES AND THEY HAVE INCREASED EXCITABILITY SO EASY TO RECRUIT AND THEY HAVE -- LOWER RESPONSE. SO CLEARLY THEY WERE SOMEHOW PARTICIPATING IN A DIFFERENT WAY IN -- SO IF YOU REMEMBER MY FIRST SLIDES ON THIS TALK OR MY SECOND SLIDES, BASICALLY WHAT I TOLD YOU IS BREVICAN IS NOT ONLY EXPRESSED IN THE PARVALBUMIN, IT'S ALSO EXPRESSED IN THE GLIA. SO YOU CAN ALWAYS CLAIM THAT BREVICAN, THE PHENOTYPE THAT WE ARE SEEING IS DUE TO NOT -- BREVICAN PHENOTYPE, I AGREE WITH THAT, BUT MAYBE IT'S DUE TO THE EXPRESSION OF BREVICAN IN THE GLIA CELLS. SO IF WE DON'T HAVE BREVICAN -- IT'S WHY WE HAVE A LOSS OF SYNAPSES AND THIS IS WHY WE HAVE A DIFFERENT INTRINSIC PROPERTIES OF THESE CELLS. SO TO SOLVE THIS QUESTION, WHAT WE DID WAS TO JUST COME UP WITH A STRATEGY WHERE WE ASSIGNED A CONSTRUCT IN WHICH WE COULD EXPRESS -- TO KNOCK DOWN BREVICAN ONLY IN THE PARVALBUMIN CELLS BECAUSE WE WERE EXPRESSING THESE -- ONLY IN THE PARVALBUMIN -- DEPENDENT CELLS, BY USING THAT, WHAT WE DID WAS TO ANALYZE ALL THE PARAMETERS THAT WE WERE LOOKING AT BEFORE TO SHOW WHETHER BREVICAN WAS IN THE PV CELLS WERE SUFFICIENT -- THAT I SHOWED TO YOU BEFORE. SO BASICALLY WHEN WITH HE KNOCK DOWN BRF CAN ONLY IN THE PARVALBUMIN CELLS, THE NUMBER OF SYNAPSES -- WILL DECREASE, MEANING THAT BREVICAN, THE FUNCTION OF BREVICAN ON NORMAL NUMBER OF SYNAPSES WAS -- FUNCTION OF BREVICAN, INDEPENDENT OF THE GLIAL CELLS. FLOOB >> I HAD ONE QUESTION. WHEN YOU LOOK AT THE PREVIOUS SLIDE, ARE ARE -- HOW DID YOU KNOW THAT THAT WASN'T ORIGINALLY A BREVICAN MINUS OR BREVICAN POSITIVE CELL? >> SO IN THE POOL OF BREVICAN MUTANT CELLS, HERE, AND I WAS SAYING THE BREVICAN MUTANTS, WE DON'T HAVE A WAY TO DISTINGUISH IN OUR PHENOTYPE WHAT IS COMING FROM -- MAYBE THE HALF OF -- I MEAN MANY OF THESE PHENOTYPES ARE COMING FOR SURE I WOULD SAY THAT THIS PHENOTYE IS NOT COMING FROM THE BREVICAN INDEPENDENT CELLS. BUT WE CANNOT DISTINGUISH BECAUSE WE CANNOT -- WITH OUR MARKER. THIS WAS OKAY, IT WAS A NICE -- IT WAS OKAY, BUT TO PATCH THE INTRINSIC PROPERTIES OF THESE CELLS AND -- AND RESCUE, WE COULD RESCUE NICELY BREVICAN POSITIVE CELLS BUT TO RESCUE BREVICAN NEGATIVE CELLS WAS SOMEHOW A NIGHTMARE BECAUSE THE PERCENTAGE IS LOWER. SO WHEN WE -- THE PROPERTIES IN THE KNOCK DOWN OF BREVICAN, ONLY IN THE PARVALBUMIN CELLS WHAT WE FOUND IS THAT THERE IS A CHANGE IN THE PROPERTIES, THE PROPERTIES HAS THE BREVICAN MUTANT CELLS IN THE PARVALBUMIN PARVALBUMIN -- POTENTIAL WIDER AND ALSO AN -- THRESHOLD LOWER. SO BASICALLY THE PROPERTIES WERE NOT IDENTICAL TO THE BREVICAN MUTANT CELLS, WE CAN DISCUSS ABOUT THAT. BUT SO IF WE KNOCK DOWN BREF BREVICAN ONLY IN THE PARVALBUMIN CELLS, THEY BECOME MORE LIKE THE BREVICAN MUTANT CELLS AND THE BREVICAN NEGATIVE CELLS. SO LESS SYNAPSES, THEY HAVE LOWER LEVELS OF PARVALBUMIN, AND THEY ARE MORE EXCITABLE BUT AGAIN, THEY HAVE LOWER RESPONSE. MEANING THAT ALL THESE PHENOTYPE WE ARE DESCRIBING IS COMING FROM THE CELL AUTONOMOUS FUNCTION OF THE -- IN THE -- BE I MENTIONED TO YOU BEFORE THERE ARE TWO BREVICAN ISOFORMS, SO WHICH IS IN BOTH OF OUR PHENOTYPES AND WERE VERY INTERESTED TO UNDERSTAND THAT BECAUSE BREVICAN 1 -- WE DON'T KNOW THE FUNCTION OF THE 2, AND BREVICAN 1 SEEMS TO BE -- SO TO ADDRESS THIS QUESTION -- THE PHENOTYPE IN THE MUTANT BACKGROUND. SO BASICALLY CONSTRUCT SIMILAR TO THE ONE I SHOWED TO YOU BEFORE, WHAT WE DID WAS TO TRY TO UNDERSTAND THE QUESTION, CAN WE RESCUE THE BREVICAN MUTANT PHENOTYPE BY PUTTING BACK BREVICAN 1, AND THE SAME WITH BREVICAN 2, SO WE INJECT THIS CONSTRUCT IN THE HIPPOCAMPUS AND ADDRESS THIS QUESTION. TO ME, THIS IS ONE OF THE MOST BEAUTIFUL -- I THINK THAT WAS QUITE RELEVANT, SO WE CAN TUCK BREVICAN AND WE CAN -- SOMETIMES WHEN YOU -- EXPRESSION OF PROTEIN, YOU WILL TAG THIS PROTEIN, IT WILL BE EVERYWHERE SO WE WILL NOT HAVE CLEAR SENSE ON WA IS THE FUNCTION OF THIS PROTEIN REALLY IN THE CELL. IN OUR CASE, THIS WAS QUITE TIGHT IN THE PLACE WHERE THEY -- WHAT WE FOUND IS THAT BREVICAN 1 IS SHOWIN G THIS BEAUTIFUL PATTERN, BREVICAN 2 WAS HAVING THIS DOTTY PATTERN THAT IF YOU WORK IN SYNAPSES, THIS ADMITTEDLY CAN HELP YOU TO IDENTIFY THAT MAYBE THIS IS NOR MORE A SYNAPTIC TYPE OF PHENOTYPE. SO WHAT WE ASKED THE QUESTION, OKAY, ANY OF THESE BREVICANS ARE ABLE TO RESCUE THE PHENOTYPE, SO WHAT WE FOUND IS THAT BREVICAN 1 IS NOT AB LE TO RESCUE THE PHENOTYPE, BREVICAN 2, THEY WERE ABLE TO RESCUE -- BREVICAN 2 IS THE ISOFORM THAT IS INVOLVED IN HAVING THE NORMAL NUMBER OF SYNAPSES IN THE PARVALBUMIN BREVICAN DEPENDENT CELLS. SO WHAT I HAVE SHOWN TO YOU SO FAR IS BREVICAN IS EXPRESSED IN THE PARVALBUMIN CELLS IN A SUBPOPULATION AND IS IMPORTANT FOR HAVING A NORMAL NUMBER OF EXCITABLE SYNAPSES IN THE PV CELLS AND THERE ARE TWO DIFFERENT ISOFORMS OF BREVICAN, ONLY THE BREVICAN 2 IS THE MAIN RESPONSIBLE OF HAVING A NORMAL NUMBER OF SYNAPSES IN THE PARVALBUMIN CELLS. BUT THE QUESTION NOW IS THAT HOW BREVICAN COST DOES THAT. YOU SAY TO CONTROL THE PLASTICITY OF THE CELLS BY -- PROPERTIES, AND THEN WE WOULD SEE HOW BREVICAN -- PLASTICITY BY -- INPUTS INTO THESE PARVALBUMIN INTERNEURONS. SO THE QUESTION, ONE OF THE THINGS THAT WE REALIZE IS THAT GOING BACK TO OUR FACILITY, WHAT WE SAW, INDEED, TWO OF THE VERY INTERESTING -- HIGHLY EXPRESSED IN THE PARVALBUMIN CELLS ARE -- WHAT WE KNOW IS THAT ONE OF THE FUNCTIONS OF 1.1 IS CONTROLLING THE THRESHOLD OF THE AXIOM POTENTIAL AND ALSO THE LATENCY. AND ONE OF THE FUNCTIONS OF -- IS CONTROLLING THE SHAPE OF THE ACTION POTENTIAL AND ALSO FINDING THE FREQUENCY OF THESE INTERNEURONS. KV3.1 -- 1.1 IS EXPRESSED IN THE TSH CELLS BUT IS QUITE -- SO HAVING THIS IN MIND, WE THOUGHT MAYBE THESE CHANNELS ARE IN PART RESPONSIBLE OF OUR SIGNATURE FOR THESE BREVICAN POSITIVE CELLS. AND WHAT WE WERE TRYING TO TEST, DIFFERENT IN THE MUTANTS AND THE CONTROLS AND WHAT WE FOUND WITH KV1.1 IS THAT KV1.1 HAS LESS EXPRESSION OF THE LEVELS AND KV1.1 IN THE MUTANTS HAS DIFFERENT -- WITH THE CONTROLS SO HERE IN THE LEFT, YOU SEE THE -- ON THE RIGHT -- AND BASICALLY WHAT WE FOUND IS WE HAVE A DECREASE IN THE -- MICRON OF THE KV1.1. THIS WAS IN THE MUTANT. BUT WHAT HAPPENED IN THE PV MUTANT. SO BASICALLY WHAT HAPPENED IS -- OF BREVICAN, WHERE WE KNOCK DOWN BREVICAN IN THE PARVALBUMIN CELLS, WHAT WE FOUND IS THAT THERE IS -- WHAT THAT MEANS. WHAT MEANS IS THAT THIS CHANGE IN THE LEVEL OF KV1.1 IN THE MUTANT, IN THE FULL MUTANT, IS NOT THE -- AUTONOMOUS -- PROBABLY -- OF THE NETWORK THAT IS -- IN DIFFERENT CELLS EXPRESSED IN BREVICAN WHICH ARE NO LONGER THERE OR MAYBE BECAUSE -- MAYBE -- THE NETWORK. IF YOU DON'T HAVE QUESTIONS ABOUT THIS, MAYBE WE CAN DISCUSS LATER BECAUSE I FOUND THAT THESE -- QUITE SURPRISED BUT IT WAS QUITE INTERESTING TO KNOW AND TO SEE THAT KV1.1 WAS CHANGING BECAUSE NETWORK WAS CHANGING, NOT BECAUSE THE FUNCTION OF BREVICAN IS SPECIFICALLY FOR THIS PARTICULAR CHANNEL. WA WE FOUND WITH KV1.1, THERE'S NO CHANGE OF THE LEVELS OF THE -- BUT WA WE FOUND IS THE CLUSTERS OF THESE -- WAS TEE CREASED AND WHEN WE -- THE KNOCK DOWN OF BREVICAN ONLY FROM THE PARVALBUMIN CELLS, WHAT WE FOUND IS THIS WAS DECREASED. -- OF BREVICAN IN THE CONTROL OF THE CLUSTERS OF KV3.1. SO HOW ABOUT THE SYNAPTIC PLASTICITY? HOW ABOUT OUR EXCITATORY INPUTS? SO THIS WAS FOR US QUITE A -- BECAUSE WHEN WE ASK THE QUESTION, OKAY, WHERE IN THE -- HAVING AN ACTION, IN THE VERY EARLY SINUS FORMATION OR HAVING AN ACTION IN THE MATURATION? SO WE DIDN'T SEE ANY CHANGE IN THE EXCITABILITY INPUTS EARLY ON, AND WE THOUGHT -- IS MORE INVOLVED IN THE -- OF THE SYNAPSES BECAUSE AT P30, WE HAVE A CLEAR DECREASE IN THE NUMBER OF SYNAPSES, AND THROUGH ONE OF THE THINGS THAT WORKING -- RECEPTORS POINT OUT ABOUT WHAT IS THE MAIN -- HOW IS SYNAPSES CAN BE MATURE, IS THAT INTERACTIONS -- WHAT WE FOUND IS THAT BREVICAN IS NOT INTERACTIVE WITH ANY OF THE OTHER RECEPTORS BUT IT IS CLEAR INTD ACTING -- WITH ALL THE -- THAT BE TEST. ON THESE THREE, I HOPE THAT YOU SEE THE -- HEAR, HEAR YOU SEE THE BANDS, AND HERE IS THE MUTANT OF 1. SO BASICALLY WHAT WE FOUND IS THAT BREVICAN IS INTERACTING -- ON HOW THIS IS HAPPENING, WE TAKE THIS -- 1 AND 4, HIGHLY EXPRESSED IN THE PV INTERNEURONS, WORKED FOR A WHILE, I THINK, HIGHLY EXPRESSED IN THE PV INTERNEURONS. A1 IS EXPRESSED -- IS QUITE ENRICHED IN THE INTERNEURONS, WE DIDN'T SEE ANY CHANGE IN -- 4. WE CHECKED -- 1 AND WHAT WE SAW IS IN THE -- OF THESE CELLS, WHAT YOU SEE HERE IS THE MEMBRANE -- AND WHAT YOU SEE HERE IS THAT WHEN YOU COMPARE CONTROLS AND MUTANTS, THERE IS A DECREASE IN THE SYNAPTIC -- FRACTION AND THERE IS AN INCREASE IN THE MEMBRANE FRACTION AND WE DON'T HAVE ANY CHANGE IN THE -- SO THE LEVELS OF BREVICAN ARE THE SAME, BUT -- CHANGE QUITE DRAMATICALLY. SO WHAT THAT MEANS, SO WHAT WE THINK THAT IS HAPPENING HERE, OF COURSE THIS IS A MODEL, I SHOWED YOU THAT BREVICAN AT THE SOLUTION LEVEL IS -- SUPER SOLUTION LEVEL IS FLANKING THE SYNAPSIS. SO FLANKING THE SYNAPSIS, FLANKING THE GLUR1 FACTORS, BUT BASICALLY THE SUPER SOLUTION WE SEE GLUR1 IS THERE, SO BASICALLY IN NORMAL SITUATIONS, BREVICAN IS THERE. -- IN THE MUTANT, WHEN WE DON'T HAVE BREVICAN ANYMORE, GLUR1 HAS THE ABILITY GOING OUT OF THE SYNAPSES AND PERHAPS IT DOESN'T HAVE THE ABILITY TO STAY IN THE SYNAPSES, AND THIS COULD BE ONE OF THE REASONS WHY THE SYNAPSES DOESN'T HAVE ANY LONGER NORMAL LEVELS OF GLUR1 IS NOT MATURE. OKAY? SO WHAT I SHOW TO YOU HERE, WE DON'T KNOW THIS IS THE WHOLE STORY ABOUT BREVICAN, WE KNOW WE HAVE SOME EVIDENCE IT'S INTERACTING WITH OTHER PROTEINS, BUT WHAT I SHOWED TO YOU IS THAT BREVICAN IS CONTROLLING THE SYNAPTIC PLASTICITY -- MATURATION OF THE SYNAPSIS BY CLUSTERING GLUA1 RECEPTORS. CLOAL KROALED BY THE CLUSTERING OF -- THIS WAS INTERESTING FOR US BECAUSE TWO OF -- ALL THESE PROTEINS ALSO CHANGE WITH BEING ATIVITY. SO THE NEXT QUESTION WE WANTED TO ADDRESS HERES WA, OKAY, IF THESE PROTEINS CHANGE WITH ACTIVITY, WHAT HAPPENS WHEN -- IS BREVICAN CHANGING DYNAMICALLY WITH ACTIVITY? AND TO ANSWER THESE QUESTIONS, WE DID TWO DIFFERENT EXPERIMENTS. ONE WAS TO USE -- CULTURES AND CHANGE THE ACTIVITY IN THE KL TOURS BY USING DIFFERENT COMPOUNDS, SO -- INCREASE ACTIVITY AND WITH KCL, AND -- INCREASED ACTIVITY WITH GABA -- AT THE SAME TIME WE WERE DECREASING ACTIVITY WITH -- WHAT WE SAW IS THAT BREVICAN LEVELS CHANGED IN THE OPPOSITE DIRECTION OF THAT ACTIVITY. SO MORE ACTIVITY, LESS BREVICAN, AND LESS ACTIVITY, MORE BREVICAN. THIS IS WHAT IT HE SHOWS HERE. BUT THIS IS SOMEHOW NOT ARTIFICIAL BUT THIS IS NOT A VERY PHYSIOLOGICAL SYSTEM SO WHAT WE DID WAS TO USE A MORE -- IN VIVO TRYING TO REPLICATE WHETHER -- OF BREVICAN. YOU PUT THE MICE INTO A CASE FULL OF -- AND SEE WHAT HAPPENS, SO YOU HAVE DIFFERENT -- AND TEST YOUR MOLECULES. SO THIS IS ALWAYS -- INCREASE IN ACTIVITY. WHAT I WILL SAY IS THAT NOBODY HAS PUT -- IN VIVO SO THE ACTIVITY HAS INCREASED, BUT WHAT WE CAN SAY IS THAT ACTIVITIES CHANGING IN THIS MODEL. WHAT WE FOUND IS WITH -- CONTROL, BREVICAN -- THE MICE THAT WERE CITED TO -- RICH ENVIRONMENT COMPARED WITH MICE HOUSED IN NORMAL CONDITIONS HAS AN INCREASE IN -- DECREASE IN BREVICAN LEVELS, AS WELL AS A DECREASE IN THE PARVALBUMIN EVELS. SO BASICALLY BREVICAN IS DYNAMICALLY REGULATE THE BY REGULATED BY ACTIVITY. SO THE POPULATION OF BREVICAN NEGATIVE CELLS IS DB COMPARED WITH THE BREVICAN POSITIVE CELLS ARE INCREASING, AND THIS IS -- THE -- BETWEEN THE TWO IS DECREASED SO BASICALLY WE HAVE LESS BREVICANS POSITIVE CELLS AND MORE BREVICAN NEGATIVE CELLS WITH -- ENVIRONMENT. OKAY? IT'S CLEAR SO FAR? AND THIS IS CONSISTENT WITH THE IDEA THAT HOW ARE THE SYNAPSES. WHAT I SHOWED TO YOU, WHEN WE HAVE LESS BREVICAN, WE HAVE LESS SYNAPSES. THIS IS CONSISTENT WITH -- IN A WAY WHEN WE ANALYZE THE NUMBER OF SYNAPSES -- WERE DECREASED. SO BASICALLY THIS IS WHAT WE HAVE HERE. THE QUESTION IS HOW THESE AFFECT AFFECT -- SO WE DID DIFFERENT TESTS BUT I WANT TO SHOW YOU ONE OF THESE TESTS WHICH IS THE DRK YOU MIGHT BE FAMILIAR WITH THAT. BASICALLY WE USE THE SPONTANEOUS -- THAT THE MICE HAVE TO EXPLORE DIFFERENT AREAS, DIFFERENT ENVIRONMENTS, AND ALSO THE IDEA THAT THE MICE ALWAYS LIKE TO -- BASICALLY IN THESE TESTS WHAT WE HAVE IS THAT THIS IS LIKE A -- BUT WE KNOW -- DIFFERENT SET. WE PUT THE MOUSE HERE, BHINT LATER, WE EXPLORE HOW MANY TIMES THE MICE DEPOSE TO THE FAMILIAR GOES TO TH E FAMILIAR VERSUS THE NOVEL. SO A CONTROL MICE SPENT MORE TIME IN THE NOVEL BECAUSE THEY ARE CURIOUS, THEY WANT TO KNOW WHAT IS THIS NEW THING, THIS NEW ARM. HIGHER NUMBER OF INTEREST, MORE TIME IS SPENT IN THE NOVEL AMPLET WE COMPARE THIS ARM. WE COMPARE THAT WITH THE MUTANT, THE MUTANT DON'T CARE, THEY THINK THAT IS -- THEY THINK IT'S A FAMILIAR ARM, THEY DON'T HAVE ANY DISTINGUISHED -- ANY DISCRIMINATION BETWEEN THE NOVEL AND THE FAMILIAR, AND THIS IS WHAT YOU SEE HERE IN THE NOVEL -- SO BASICALLY THE MUTANT MICE, THEY ARE NOT ABLE TO RECOGNIZE THAT THERE IS A NOVEL -- ARM HERE. THIS HAS BEEN ASSOCIATED WITH CERTAIN MEMORY. SO WE ASK THE QUESTION BECAUSE I TOLD YOU BEFORE BREVICAN IS EXPRESSED EVERYWHERE SO WE HAD TO SOLVE WHETHER THIS IS THE BREVICAN EXPRESSED ON THE PARVALBUMIN CELLS AND TO DO THAT, WE ARE USING THE CRE DEPENDENT -- WE KNOCK DOWN BREVICAN IN THE HIPPOCAMPUS AND TEST THE ANIMALS WITH A SIMILAR TEST AND WHAT WE FOUND IS THAT MORE TIME SPENT IN THE NOVEL ARM, THE MUTANTS ARE NOT ABLE TO DISCRIMINATE THAT THERE IS A FAMILIAR OR NOVEL ARM IN THE ANALYSIS WE PERFORMED. SO BASICALLY FROM THAT, I CONCLUDE THIS PART, WITH THE YTD THAT BREVICAN IS EXPRESSED IN THE PARVALBUMIN INTERNEURONS. I HOPE I COULD CONVINCE YOU THAT BREVICAN IS -- CONTROL IN ELASTICITY OF THE CELLS WITH KV3.1 CHANNELS AND ALSO BREVICAN IS -- GLUA1 RECEPTORS. WHAT MATTERS FOR THESE CELLS IS THAT WE THINK THAT BREVICAN IS ABLE TO GATE THE INFORMATION OF THESE PARVALBUMIN CELLS WHICH WE GAINED IN THE CIRCUITRY GI BI-INCREASING THE DRIVE OF THESE PARVALBUMIN CELLS, HAVING MORE SYNAPSES OR LESS SYNAPSES, BUT ALSO BY DECREASING THE EXCITABILITY OF THESE PARVALBUMIN CELLS, AND THIS IS KEY FOR WHAT IS THE FUNCTION OF THESE PARVALBUMIN CELLS IN THE NETWORK, OKAY? SO THE THIRD PART OF MY TALK THAT IS GOING TO BE MORE BRIEF THAN BEFORE IS THAT WHAT IS THE -- CONSEQUENCE OF -- THE DEVELOPMENT OF THESE CORTICAL NETWORKS. I WANTED TO SHOW TO YOU THIS PICTURE IN WHICH WE SAW THAT WE HAVE BEEN WORKING FOR MANY YEARS WHICH -- PART OF THE WORK OF ANDRES HERE AND BASICALLY WHAT WE SAW IS THAT AV4 IS EXPRESSED IN THE SYNAPSIS OF INTERNEURONS -- RECEPTOR, YOU MIGHT KNOW BECAUSE ALL THE WORK, BEAUTIFUL WORK OF ANDRES HERE, IT BINDS TO THE -- PROTEINS AND IT HAS BEEN LINKED TO SCHIZOPHRENIA. AGAIN IF YOU ARE INTERESTED, I CAN DISCUSS THAT AT THE END OF MY TALK, BUT BASICALLY THE MAIN PART HERE I WANT TO SHOW YOU IS THAT HOW -- IS EXPRESSED IN DIFFERENT INTERNEURONS IN THE PARVALBUMIN INTERNEURONS BOTH -- AND CELLS AND IS THIS THE WORK OF ANDRES' LAB AND ALSO OUR LAB LABS, I HAVE TO SAY THIS LAST PART OF THE WORK HAS BEEN DONE IN COLLABORATION WITH MY COLLEAGUE, AND BUTTE TEE OF THIS SYSTEM IS THAT NOT ONLY THAT WE CAN EXPLORE WHAT IS THE ROLE OF -- 4, LINKED TO SCHIZOPHRENIA, THIS IS VERY BEAUTIFUL FOR -- 4, WE'RE GOING TO EXPLORE ARE WAYS -- WHAT IS THE FUNCTION THE GENE HAS IN THE SYNAPSES, BUT ANOTHER BEAUTY OF THIS WORK, OF THIS GENE IS THAT IF THIS GENE HAVE INVOLVED IN THE -- WE CAN ASK THE QUESTION, OKAY, WHAT IS THE ROLE OF THESE INTERNEURONS? WHY DO THEY NEED TO HAVE A NORMAL -- DURING DEVELOPMENT? AND TO EXPLORE THIS QUESTION ABOUT THE FUNCTION, I THINK IT'S A BEAUTIFUL SYSTEM. BASICALLY WHAT WE FOUND SOME TIME AGO IS AV4 IS INVOLVED IN THE THE WIDENING OF THESE INTERNEURONS, THIS CAUSED INCREASE IN EXCITATION THAT LEADS TO A CHANGE IN ACTIVITY AT THE LEVELS OF NETWORK THAT CAUSE A DEFICIENCY IN SOME OF THE -- THAT WE -- AT THAT TIME. BUT WHAT HAPPENED WITH THE OTHER POPULATION? WA WE FOUND IS THAT -- IS EXPRESSED IN A POPULATION OF SOMATIC -- TO THE PYRAMIDAL CELLS. -- BECAUSE DIFFERENT AREAS THAT WE HAVE. ONE IS THAT IT'S A VERY LOW NUMBER OF -- AND THE SECOND EVIDENCE IS THAT WAIT AND SEE FUNCTION OF -- 4 IN THE SOMATIC PARVALBUMIN INTERNEURON -- SO THIS IS THE WORK THAT MAYBE WE COULD SOLVE THE QUESTION IS -- 4 ALSO INVO LVED IN THE BIDE ENING OF THE -- INTERNEURONS FROM THE BASIC POINT OF VIEW, BUT THE SECOND QUESTION FOR US WAS QUITE KEY WAS THAT NOBODY KNEW, THE REASON WHY NOBODY KNEW, THESE INTERNEURONS -- GENETICALLY SPEAKING OR FORM CLOJICALLY SPEAKING ARE QUITE PROMISCUOUS WITH THE PYRAMIDAL CELLS. SO ANYTHING YOU TARGET HERE WILL AFFECT THE PYRAMIDAL CELLS. AND WE THOUGHT THAT WE HAVE THE PERFECT TOOL BECAUSE WE KNOW THAT INTERNEURONS -- 4 IS ONLY EXPRESSED IN THE IPT NEURONS SO WE COULD DO ANYTHING IN INTERNEURONS BY CROSSING OUR CONDITIONAL MUTANTS WITH A CRE-DEPENDENT DRIVER THAT WAS EXPRESSED IN THE -- INTERNEURONS BUT ALSO IN THE PYRAMIDAL CELLS BUT WE DON'T CARE ABOUT THE PYRAMIDAL CELLS BECAUSE AV4 IS NOT EXPRESSED IN THE PYRAMIDAL CELLS. AND MAYBE BY HAVING THIS CROSS, WE COULD FIRST, AS I SAID, KNOWING WHAT IS THE ROLE OF ESH B4 -- SO WE REPLICATE THIS WORK SO THAT -- AROUND 55%, WE SAW THAT ESH WHEN WE TRY TO UNDERSTAND WHAT IS THE FUNCTION OF ERB B4, WHAT IS THE ROLE OF ERB B4, WHAT WE FOUND IS IT'S EXPRESSED, WE COULD SOMEHOW TRACK THE TERMINALS OF THESE -- THESE --IND PENDANT MARKERS, LABEL WHAT WE THINK THAT IS THE ERB B4 INDEPENDENT CELLS WHICH ARE THE MAJORITY OF THE -- CELLS, AND WHAT YOU SEE HERE IS THIS IS THE -- THIS IS WHAT THE QUANTIFICATION SHOWS TO YOU, SO BASICALLY THE WIDENING OF THESE INTERNEURONS WAS DECREASED INTO THE PYRAMIDAL CELLS BUT TO SHOW THAT THE TRANSMISSION BETWEEN THE -- CELLS AND THE PYRAMIDAL CELLS WAS ALSO SOMEHOW IMPAIRED WAS TO USE A CRE-DEPENDENT CONSTRUCT -- INTO THE INTERNEURONS AND THIS WAS THE WORK OF ANDRE THAT IN A -- WAY, THIS WAS -- SO WE SOMEHOW ADDRESSED THE QUESTION OF WE PATCHED THE PYRAMIDAL CELLS, WE AK TAIGHT -- WE BLOCK WHAT ANDRE FOUND IS THAT INDEPENDENT OF THE -- OF THE LASER, SO BASICALLY THE EXPERIMENT SHOW -- WE HAVE -- RIGHT IN BETWEEN -- AND THE PYRAMIDAL CELLS BUT ALSO AT THE TRANSMISSION LEVEL -- SO THIS IS THE -- OF OUR FINDINGS AND I EVEN GO INTO THE OTHER LOSS OF INHIBITION IN THE PV CELLS AS WELL, LOSS OF EXCITATORY -- THE QUESTION HERE, DOES THIS AFFECT BEHAVIOR -- PHENOTYPES, AND JUST TO SUMMARIZE, WE DIDN'T FIND A MAJOR PHENOTYPE IN THE WORKING MEMORY OF THESE CELLS. OR ANY INVOLVEMENT OF THESE CELLS IN A WORKING MEMORY, BUT WHAT WE FOUND IS THAT WHEN WE USE THE -- DISPLACEMENT THAT IS KIND OF -- IN WHICH YOU HAVE THE SAME OBJECT AND THIS DISPLAYS THE OBJECT 10 CENTIMETERS AWAY FROM THE POSITIONS AND ASK THE QUESTION IS THAT HOW THE MICE ARE ABLE TO DISCRIMINATE THIS CHANGE IN POSITION. WHAT WE FOUND IS THAT THE MUTANTS THAT ARE LACKING OF ERBB4 AND HAS THESE DEFICITS, THEY WERE ABLE TO HAVE A DECREASE IN THE -- RATE. SO BASICALLY THEY ARE NOT ABLE TO UNDER UNDERSTAND THAT WE HAVE -- CENTIMETERS AWAY FROM THAT POSITION. WHEN WE GO TO -- BUT WHAT WE FOUND IS THAT WHEN WE COMPARE THE SECOND -- THEY ARE ABLE TO FIND THE HIDDEN PLATFORM. ON THE SECOND TRY THEY ARE NOT ABLE TO FIND THE HIDDEN PLATFORM SO THEY NEED MORE TIME TO DO IT. IT HAPPENS IN THE FIFTH TRIAL, NOT THE SECOND TRIAL. SO MAYBE WE HAVE A SPECIAL -- DEFICITS WHEN WE HAVE LOSS OF THE INTERNEURON WIDENING AND THE QUESTION IS, WHAT THAT MEANS IN TERMS OF NETWORK. THIS IS THE WORK THAT JORGE BROTONS DID IN THE LAB, SO IN THE OPEN FIELD, ONE OF THE THINGS THAT INSPIRED US, THE WORK COMING FROM PETER'S LAB, WHEN -- WAS THERE, THEY FOUND THAT ALTHOUGH NOTHING WAS KNOWN ABOUT THE -- FUNCTION, THEY THINK THAT MAYBE THE -- CELLS HAS SOMETHING TO DO WITH THE -- HE CELLS. THE REASON THEY THOUGHT THAT IS BECAUSE EVERY TIME THAT -- WE HAVE -- THAT WAS FOLLOWING UP CLOSELY -- SO BASED ON THAT, WE THOUGHT, OKAY, HOW IS THE PLATE CELLS IN THESE MUTANTS. -- IN THE CA1 AND THE MICE WERE EXPLORING AND IF YOU ARE FAMILIAR WITH THE PLATE CELL, THIS IS FOUR DIFFERENT PLATE CELLS, WHICH IS -- THEY ARE -- IN A PARTICULAR -- IN THE FIELD HEAR, HEAR OR THERE AND WHEN HE RECORD THE MUTANTS, MANY OF THE MUTANTS WERE HAVING THIS KIND OF FIELD WHICH WAS QUITE DISORGANIZED. TO SEE THAT IT WAS QUITE VERY NICE -- VERY BAD DISORGANIZATION OF THE PLACE CELL FIELDS. SO WHEN JORGE QUANTIFIED THIS PARAMETER, WHAT HE FOUND WAS THE -- FIELD AREA WAS INCREASED, THIS WAS VERY OBVIOU, THEIR RATES WAS INCREASED AND THE -- WHEN WE'RE COMPARING ALL THESE PLACE CELL -- WAS DECREASED. SO CLEARLY THE PLACE CELL FIELD WAS DEFICIENT IN THESE CCK MUTANT CELLS THAT WERE HAVING AN -- IN DEVELOPMENT. SO HOW ABOUT THE STABILITY OF THESE PLACE CELLS? THIS IS ANOTHER PARAMETER THAT YOU CAN MEASURE ON THESE PLACE CELLS. SO BASICALLY THIS IS -- IN THE SAME SESSION, TWO EXAMPLES OF PLACE CELLS, 1 AND 2, AND YOU WILL SEE THE SAME CELL 10 MINUTES LATER. SO IN THE CONTROL SITUATION, WHAT HAPPENS IS MANY OF THESE CELLS ARE QUITE UNSTABLE, SO YOU SEE -- IN A SIMILAR COORDINATING IN THE FIELD. WHAT HAPPENS WITH THE MUTANT CELLS IS NOT ONLY DO THEY HAVE DIFFERENT -- VERY EXPANDED PLACE CELL FIELD OR THEY HAVE -- 10 MINUTES LATER, THEY ARE -- CLEARLY A DEFICIENCY IN THE CELL. WHEN WE QUANTIFIED THIS, WE HAD VERY SIGNIFICANT DECREASE -- MEANING THAT SO THE QUESTION -- OF THE LEVELS OF BEHAVIOR. THIS IS WHAT HAPPENED, THIS IS A VERY STRONG CORRELATION BETWEEN HAVING LESS STABILITY -- TO DISTINGUISH -- WAS MOVING 10 CENTIMETERS AWAY. SO THE ONE THING WE HAVE HERE IS THAT THE PYRAMIDAL CELLS WERE RELEASED -- WILL BIND TO THE CD1 RECEPTORS THAT ARE PLACED IN THESE TERMINALS OF THE CYSTIC INTERNEURONS FOLLOW UP WHAT THE CLASSICAL SIGNATURE OF THESE CELLS WHICH IS THE -- OF INHIBITION, WHERE BLOCKED INHIBITION FROM THESE INTERNERONS. AND THESE CELLS WILL BE HIGHLIGHTED LIKE IN THE PLACE CELL. WHAT HAPPENS IN THE -- CELLS IS THAT -- TYPICAL CONTROL -- SO THIS IS WHY MAYBE WE DON'T HAVE A CHANCE IN THE -- THIS IS LIKE -- EXPRESSION OF THE PLACE CELL FIELD. WHAT HAPPENED IN THE MUTANT? IN THE MUTANT -- THE -- INHIBITION OF LOWER NUMBER OF SYNAPSES BUT IN THE SAME MUTANT, THE OTHER PYRAMIDAL CELLS TSH WE HAVE A -- OF THIS INHIBITION AND THIS IS WHY MAYBE WE HAVE -- IN THE -- PYRAMIDAL CELLS AROUND. THIS IS A MODEL, OF COURSE, AND WE CAN DISCUSS WHETHER THIS MAKES SENSE OR NOT. SO I JUST WANT TO END MY PAREN TAIG, I SHOW TO YOU TWO MODELS IN WHICH DIFFERENT INTERNEURONS ARE PLAYING A ROLE THE A DIFFERENT NETWORK LEVELS AND FUNCTION THAT MAYBE ARE CORRELATED WITH DIFFERENT BEHAVIORS. I'M JUST GOING TO END MY PRESENTATION TO HIGHLIGHT THE PEOPLE THAT HAVE BEEN WORKING IN THE WORK THAT I PRESENTED TO YOU TODAY. THE FIRST PART OF THIS -- EMELIA, ANDRE, ANTONIO AND DAVID. THE SECOND PART, BREVICAN, I WOULD LIKE TO HIGHLIGHT THE FIRST OF THE MANUSCRIPT WHICH IS EMILIA WITH THE HELP OF ANDRE AND LAST PART WHICH IS MORE -- MY COLLABORATORS DONE BY ISABELA. THIS IS LONDON, BELIEVE IT OR NOT. WE HAVE IN SUMMER SUN AND THIS IS WHAT WE CALL THE BEATS, IN THE CENTER OF LONDON JUST HERE UNDERNEATH THE -- VERY CLOSE TO LONDON BRIDGE, AND THIS IS JUST TO SHOW YOU THAT -- IF YOU ARE -- YOU WANT TO -- YOU ARE WELCOME ANY POSTDOC POSITION TO APPLY HERE AND WE ARE HAPPY TO RECEIVE YOU. THIS IS MY FUNDING, MANY PEOPLE HAVE BEEN ALSO INVOLVED IN THIS WORK THAT I DIDN'T SHOW UP HERE. THANK YOU FOR YOUR ATTENTION. [APPLAUSE] >> QUESTIONS? [OFF MIC] >> FOR THE FIRST QUESTION, YOU'RE ASKING IN THE FIRST QUESTION IS THAT SO IF I CLAIM THAT, SAY, PERHAPS DIFFERENT INTERNEURONS HAVE DIFFERENT SIGNATURES. I MEAN, I WILL SAY I DIDN'T HAVE THE TIME, BUT IT'S NOT HOW -- EXTRACT GENES THAT PLAY A ROLE IN THE GENERAL SYNAPSE FORM RANGE OF MOTION LIKE FROM PYRAMIDAL CELLS, ALL THE GENES THAT ARE COMMON ARE -- IN THIS BECAUSE WE GO FOR -- GENES THAT ARE IN -- IN THESE THREE POPULATIONS SO FOR SURE, THERE ARE COMMON GENES THAT ARE -- REGULAR ACTIONS IN THE SYNAPSES BUT SO WHAT WE SEE IS THAT THERE ARE VERY SPECIFIC PROGRAMS THAT ARE REGULATING THE -- AND WE HAVE -- GENES WE ARE TESTING TO SEE WHETHER THIS IS TRUE AND HAVE EVIDENCE THAT THIS IS THE CASE. FOR THE SECOND, SO BASICALLY WHAT YOU SAY IS SO WHAT IS MAYBE THE DIFFERENT -- IF I UNDERSTOOD WELL, THE DIFFERENT POSITION OF THE MOLECULE IF IT'S INPUT-OUTPUT, WHEREAS COMPARING WITH OTHER PARTNERS THEY'RE INTERACTING WITH. SO IN THE CASE OF BREVICAN, CLEARLY IT'S POST SYNAPTIC. IN THE CASE OF -- 4, FOR INSTANCE, CLEAR TA THE EXCITATORY SYNAPSIS IS -- SYNAPSIS. -- 4 IS SYNAPTIC IN THE -- CELLS AND -- INTERNEURONS BUT IT'S NOT -- IN THE BASKET POPULATION SO THERE ARE CLEARLY COMPARTMENT LIIZATION IN SOME OF THE GENES. OF COURSE IN GENES THAT ARE MORE GENERAL, IT WILL BE SOMETHING THAT ALL THE PARTNERS WILL BE INTERACTING. I HAVE TO SAY IN GENERAL WHAT I SEE IS THAT IT'S VERY CLEAR DIFFERENT COMPARTMENTIZATION MAKES SENSE FOR EXCITABILITY SYNAPSIS AND BECAUSE IT'S VERY DIFFERENT -- THAN INHIBITORY SYNAPSIS. THE QUESTION THAT WOULD BE NICE TO SEE, WHAT HAPPENS WITH THE INHIBITORY SYNAPSES. FOR BREVICAN AGAIN, THE INHIBITORY SYNAPSIS AT THE -- IS NOT DEPENDENT ON BREVICAN. NEITHER -- BUT OTHER ARE -- SOL IN THE POST SYNAPSIS, ONLY THE EXCITATORY WILL DEPEND ON BREVICAN. THIS HAPPENS AGAIN ALSO FOR -- 4, IN THE PARTLY CLOUDY INTERNEURONS, NOT DEPENDING ON BREVICAN EITHER. >> [INAULD [INAUDIBLE QUESTION] >> IN THE BIOCHEMISTRY, THE ONE THAT MOVES? >> YEAH. >> WITHIN THAT, IT MOVES IN THE PARTLY IN THE BE PARVALBUMIN INTERNEURON. WHEN WE GO TO THE SYNAPTIC LEVEL, WE COULD SEE THAT THE SYNAPSIS THAT IS EXPRESSING -- 1 ARE MISSI NG THERE. BUT THIS IS A REALLY INTERESTING QUESTION THAT HAS BEEN -- FOR A WHILE BECAUSE WE CHECK IN THE SOMA, WE KNOW IN THE WAY WE HAVE DONE THE -- SOLUTION FOR BOTH GLUA1 AND BREVICAN IN THE SYNAPSIS IS IN THE SOMA BECAUSE WE IDENTIFY -- IN THE PV CELL AND THEN WE GO TO THE THREE QUARTERS -- BUT WHAT WE THINK IS THAT -- IS DIFFERENT IN THE SOMA AND -- DENDRITE COMPARING WITH THE DISTAL DENDRITES, MAYBE CHRIS HAS SOMETHING TO DO HERE, MAYBE IN THE SOMA AND THE PROXIMAL DENDRITES -- AND MAYBE -- AND PERHAPS UPPER WE HAVE A DIFFERENT COMPOSITION AND THIS IS WHY -- CLEARLY BREVICAN ONLY WILL BE SUPPORTING -- 1 # 1 -- IN THE SOMA. SO FARTHER THAN THAT, MAYBE SOMETHING ELSE, AND INDEED OUR HYPOTHESIS THAT IS NOT PROOF BECAUSE IT IS SHOWN IN THE HIPPOCAMPUS -- COMPARING WITH THE ONES THAT ARE COMING CLOSER TO THE SOMA THAN MAYBE CA3 BECAUSE THIS IS WHERE I -- ONLY CA1, BUT YEAH, THIS IS THE QUESTION WE HAVE BEEN THINKING ABOUT A LOT. >> [INAUDIBLE QUESTION] DID YOU EVER LOOK THE A DIFFERENCES IN THE TWO ISOFORMS, UP OR DOWN ACTIVITY, OR IS ONE PREFERENTIALLY AFFECTED MORE THAN THE OTHER? >> SO THE ONLY WAY THAT WE COULD DO THAT WAS IN -- BECAUSE -- BETWEEN THESE TWO ISOFORMS, SO IN THE -- WHAT WE FOUND IS THAT BY QPCR, WE HAVE A CHANGE IN THE BREVICAN EXPRESSION IS AND 2 INDEPENDENT OF WHICH -- SO WE DO -- ONE MONTH AND WE HAVE CHANCE IN BOTH. WHAT I CAN SAY IF THIS CAN BE RELATED OR CORRELATED, YOU -- MAYBE DIFFERENT -- WOULD GIVE DIFFERENT -- DIFFICULT TO COMPARE, IS THAT BREVICAN 2 IS SENDING MUCH MORE THAN BREVICAN 1. BREVICAN IS IS NOT SIGNIFICANT SIGNIFICANT -- BUT THE THING IS THAT WE CANNOT SEE WHERE IT'S COMING THIS CHANCE MAYBE GLIAL CELLS ALSO. [INAUDIBLE QUESTION] HOW MUCH DOES IT REPRESENT, DO YOU THINK? >> I DON'T HAVE A CLUE IN TERMS OF PERCENTAGE. THE MEASURE IS -- THIS IS THE MEASURE -- THIS IS THE -- SO IS SOMEONE ELSE THERE. WHAT I CAN SAY IS MAYBE -- WE HAD TO BE CAREFUL WHEN WE SAY THAT -- ARE DOING THE SAME, BECAUSE WHAT WE SAW HERE IS THAT BREVICAN IS NOT ONLY DOING THIS -- BUT -- IN THE SYNAPTIC SYNAPTIC -- THE MATURITY OF THESE CELLS. SO THAT DOESN'T MEAN THAT OTHER MOLECULES ARE DOING THE SAME. >> [INAUDIBLE] >> EXACTLY. BECAUSE SO FAR MOST OF THE PV CELLS HAS -- BUT THEY DON'T -- I'D LIKE TO THINK THIS IS NOT SOMETHING THAT IS CELL FATE, THAT THIS IS SOMETHING THAT IS CELL STATE, BECAUSE AT LEAST WE CAN MOVE BREVICAN DOWN. WE HAVE TO DO EXPERIMENTS TO SEE WHERE WE CAN MOVE BREVICAN UP AND SEE WILL IT BE EXPRESSED IN BREVICAN, BUT YEAH, I MEAN -- >> OKAY. THANK YOU VERY MUCH. >> THANK YOU.