TODAY IT'S MY PLEASURE TO WELCOME RACHEL WILSON WHOSE GOING TO GIVE A TALK TODAY. RACHEL HAS AN INTERESTING SCIENTIFIC BACKGROUND AND I'VE ACTUALLY SORT OF KNOWN RACHEL SINCE ACTUALLY WHEN SHE WAS A GRADUATE STUDENT AND I FOLLOWED HER, THE PROGRESSION OF HER CAREER WITH A LOT OF INTEREST. SO, RACHEL RECEIVED A BACHELOR'S DEGREE IN HAD CHEMISTRY FROM HARVARD COLLEGE AND THEN WENT ON TO DO HER Ph.D. WORK IN THE LAB OF ROGER NICKEL AT UCSF WHERE SHE TODAYED SYNAPTIC TRANSMISSION AND PLASTICITY IN THE HIPPOCAMPUS AND DURING THIS TIME SHE MADE INTERESTING AND INFLUENTIAL DISCOVERIES WHEN SHE WAS 1 OF THE FIRST PEOPLE TO DISCOVER THAT THE ABOVE CAN RELEASE ENDOCANNABINOIDS WHICH ACT AS RETINAL RETROGRADE MESSENGERS, ACTIVATING CB 1 RECEPTORS AND SUPPRESSING SYNAPTIC TRANSMISSION. THESE WERE THE FIRST STUDIES TO SHOW THAT NEURONS IN THE CNS, WERE THE SOURCE OF THE ENDOGENOUS LIGANDS FOR THE CB 1 RECEPTORS AND THIS WORK REALLY SERVED AS A STARTING POINT TO REALLY--TO OPEN UP A FIELD OF ENDOCANNABINOID RESEARCH WHICH HAS EXPANDED AND GROWN AND CONTINUES TODAY AND HAS BEEN INFLUENTIAL IN MY WORK AS A POST DOC AND MY WORK IN MY LAB AT NIH. AND THESE EXPERIMENTS THAT SHE DID AS A GRADUATE STUDENT RESOLVES QUESTIONS THAT HAD PUZZLE SAID A NUMBER OF LABS FOR ABOUT 10 YEARS AND AS AN INDICATION OF THE IMPACT OF THE WORK, I CHECKED RECENTLY AND FOBBED THAT HER PAPERS HAVE INSIGHTED SEVERAL TIMES IN THE PAST 10 YEARS. AFTER RECEIVING HER Ph.D. RACHEL CHANGED SOMEWHAT IN HER--IN HER RESEARCH AREAS TO DO POSTOCTETERAL, ATICAL TECH WHERE SHE STUDIED INSECT OLFACTION AND SPECIFICALLY IN DO SOV WELL, AND PREVIOUSLY DROSOPHILA HAD BEEN A POPULAR MODEL SYSTEM BECAUSE OF THE POWERFUL GENETIC APPROACHES THAT IT PROVIDED BUT FROM A NEUROBIOLOGICAL PERSPECTIVE IT WAS AN ATTRACTABLE ORGANISM BECAUSE ELECTROPHYSIOLOGICAL TECHNIQUES NEAR TODAYING TRANSMISSION HAD NOT--HAD NOT BEEN DEVELOPED, HOWEVER RACHEL WAS NOT DETERRED BY THIS OBSTACLE AND SHE WENT ON TO DEVELOP METHODS FOR WHOLE CELL CLAMPED RECORDINGS IN THE DROSOPHILA BRAIN AND THIS WORK PROVIDED UNPRESIDENTED INSIGHT INTO THE DROSOPHILA NERVOUS SIZE. SHE BECAME A PROFESSOR IN THE DEPARTMENT OF NEUROBIOLOGY IN HARVARD MEDICAL SCHOOL IN 2004 WHERE SHE CONTINUED AND GREATLY EXTEND THD WORK. SHE'S NOW AN ASSOCIATE PROFESSOR AND HER LABs HAS GOTTEN OFF TO AN EXTREMELY PRODUCTIVE START AS INDICATED BY HER OUTSTANDING PUBLICATION RECORD, THE PLACEMENT OF GRADUATE STUDENT AND POST DOCS FROM HER LAB, AND BY A NUMBER OF IMPORTANT HONORS AND AWARDS SHE'S RECEIVED INCLUDING A MACARTHUR FELLOWSHIP, SOCIETY FOR NEUROSCIENCE YOUNG INVESTIGATOR AWARD AND RECENTLY RACHEL WAS NAMED HOWARD HUGH'S INSTITUTE EARLY CAREER SCIENTIST SO I WOULD LIKE TO WELCOME RACHEL WHO WILL GIVE A SEMINAR TODAY ENTITLED MIND THE GAP, A NETWORK OF ELECTRICAL SYNAPSES LINKING OLFACTORY IN THE A-10 O LOBE. SO THANK YOU RACHEL. [ APPLAUSE ] >> THANK YOU STEPHAN FOR THAT INTRODUCTION AND THANK YOU FOR THE INVITATION TO BE HERE TODAY TO SPEAK TO YOU. IT'S A GREAT PRIVILEGE AND HONOR. MY LAB IS INTERESTED IN EVENTS THAT HAPPEN IN EARLY PROCESSING, EVENS THAT HAPPEN NEAR A PERIPHERY OF SYSTEM SYSTEM. AND AND THEY USE DURING THE SENSORY PROCESSING, AND INTERESTED IN CHARACTER ITIZING THE SYNAPTIC AND CELLULAR MECHANISMS OF THESE TRANSFORMATIONS HOW THEY'RE IMPLEMENTED AND FINALLY WE'RE INTERESTED IN KNOWING WHY THESE TRANSFORMATIONS MIGHT REPRESENT ADAPTIVE COMPUTATIONS FROM THE PERSPECTIVE OF THE ORGANISM AND TO GIVE YOU A SENSE OF WHAT WE MEAN, I COULD ILLUSTRATE THIS BY PROVIDING 1 EXAMPLE, THAT'S THE EXAMPLE OF THE GAIN CONTROL PROBLEM. SO IF YOU CONSIDER THIS VISUAL SCENE AND YOU IMAGINE WHAT YOU MIGHT SEE UNDER CONDITIONS OF VERY LOW LIGHT, THIS IS THE SIGNAL THAT WOULD BE HITTING YOUR RETINA AND YOU WOULD HAVE GREAT DIFFICULTY IDENTIFYING OBJECTS IN THIS SCENE UNLESS YOUR VISUAL SYSTEM TURNS UP THE GAIN, BUT WALKING AROUND WITH HIGH GAIN ALL THE TIME IS NOT A GOOD THING BECAUSE IN THAT SITUATION, THE SYSTEM IS LIKELY TO BECOME SATURATED AND WHAT'S NEEDED IS AN ADJUSTABLE GAIN CONTROL, SUCH THAT IS THE NUR O CIRCUIT AS A WHOLE CAN EXIST IN MULTIPLE DIFFERENT STATES AND THE STATE OF THE SYSTEM NEEDS TO BE SPECIFIED, BY THE CURRENT STATISTICS OF THE STIMULI, THAT THE SYSTEM IS SEEING, SO COMPUTATION, ADAPTIVE GAIN CONTROL IS THE KIND OF COMPUTATION THAT'S FUNDAMENTAL TO EARLY SENSORY PROCESSING; AND THE RETINA IS ACTUALLY REASONABLY WELL UNDERSTOOD, MY LAB IS JUST INTERESTED MORE BROADLY IN UNDERSTANDING HOW THIS KIND OF ADAPTIVE COMPUTATION IS IMPLEMENT INDEED OTHER EARLY SENSORY PROCESSING CIRCUITS, AND IN PARTICULAR WE HAVE INVESTIGATED PROBLEMS LIKE THIS, IN THE FRUIT FLY DROSOPHILA MODEL CITIZEN LLANO GHASTER AND IN PARTICULAR WE FOCUSED THIS TURNED OUT TO BE A USEFUL MARKET FOR CERTAIN REASONS. FIRST IT'S RELATIVELY STRAIGHT FORWARD TO PERFORM IN VIVO WHOLE CELL PATCH CLAMP RECORDINGS FROM GENETICALLY LABELED NEURONS IN THE FLY BRAIN IN THE AWAKE ORGANISM ANOTHER VIRTUE OF COURSE IS THAT WE HAVE AVAILABLE TO US, A VARIETY OF GENETIC TOOLS THAT ALLOWITOUS LABEL IDENTIFIED CELLS BUT ALSO MANIPULATE THOSE CELLS AND FINALLY 1 NICE THING ABOUT INVERT GREATS AND INSECT SYSTEM THAT THE NUMBER OF NEURONS INVOLVED IN ANY GIVEN NEURAL CIRCUIT IS COMPARATIVELY SMALL, SO, IN THE ANTENNA LOBE FOR EXAMPLE, THERE ARE SORT OF ORDER HUNDREDS OF NEURONS INVOLVED IN THIS CIRCUIT, AND THAT MAKES THE PROBLEM A MORE ATTRACTABLE 1 FOR US. SO I SHOULD TELL YOU SOMETHING ABOUT THE ANATOMY OF THE CIRCUIT THAT I'M GOING TO BE TALKING ABOUT. THE ANTENNA LOBE IS ROUGHLY ANALOGOUS TO THE OLFACTORY BULB LIKE THE BULB I RECEIVE TED TREKED INPUT FROM OLFACTORY RECEPTOR NEURONS AND EACH RECEPTOR NEURON, EACH ORON, EXPRESSES A SINGLE GENE AND ALL THE ORONs THAT EXPRESS THE SAME GENE PROJECT THEM TO THE SAME COMPARTMENT OF NEUROPILL IN THE ANTENNA LOBE WHICH IS THE GLUMARILUS,/7IÑ> THERE THEY MAKE SYNAPSES WITH SECONDARY PROJECTION NEURONS OR PIONS AND THESE ARE ANALOGOUS TO THE MICROBRITSLE BULB AND IT EXTENDS INTO JUST A SINGLE GLUE MARULOUS, MEAN TGF GETS DIRECT INPUT FROM JUST A SINGLE ORON TYPE. BUT IT'S ALSO INTERCONNECT BIDE A NETWORK OF LOCAL INTERNEURONS AND IT'S IMPORTANT FOR YOU TO NOTE THAT A GIVEN ODOR, EVEN IF IT'S A PURE ODOR OF MONOMOLECULAR ODARE WILL INTERACT WITH MORE THAN 1 RECEPTOR TYPE AND AND THAT MEANS THAT AN ODOR RESPONSE IS OFTEN SHAPED NOT ONLY BY FEET FORWARD INPUT, FROM THE COGNATE OONS BUT ALSO LATERAL INPUT THIS IS RELAYED BY INTERNEURONS. SO I'M GOING TO GIVE YOU A SENSE OF WHAT THESE RECORDINGS LOOK LIKE, WHAT THE RAW DATA LOOKS LIKE, THIS IS AN EXAMPLE OF AN A RECORDING WE MADE FROM A PROJECTION NEURON IN THE LOBE. YOU CAN SEE THESE PONE TANIOUS EPSPs. IT TURNS OUT THESE LARGE SPONTANEOUS EPSPs REFLECT INPUT FROM OLFACTORY RECEPTOR NEURONS, OR AS IT TURNS OUT SPIKE SPONTANEOUSLY EVEN IN THE ABSENCE OF ODORS AND THEN WE PUFF ON AN ODOR AND WE SEE DEPOLARIZATION OF MEMORY POTENTIAL AND THE CELL FIRES A TRAIN OF SPIKES. SO, FOR THE PURPOSES OF THIS TALK, YOU NEED TO KNOW 1 SORT OF FUN FACT ABOUT THE ON DROSOPHILA OLFACTORY SYSTEM AND THAT IS THE FLY HAS 2 OLFACTORY ORGANS. THE ANTENNA AND THE MAXILLARY PALP. ORONs IN BOTH OF THESE STRUCTURES PROJECT TO THE ANTENNA LOBE BUT A GIVEN GLUMARIU, RECEIVES IT FROM THE PALP. THAT MEANS WE CAN MANIPULATE INPUT INDEPENDENTLY TO ANTENNA GLUMARILY, BY MANIPULATING THEM INDEPENDENTLY. SO I'M GOING TO GIVE YOU AN OUTLINE OF THE WORK I'LL TELL YOU ABOUT TODAY AND I'LL START BY JUST SORT OF GIVING AWAY THE PUNCH LINE OR THESIS STATEMENT FOR THE 2 PARTS OF THE TALK. SO IN THE FIRST PORTION OF THE TALK, I'M GOING TO SHOW YOU EVIDENCE THAT ARGUES THAT ACTIVITY SPREADS BETWEEN OLFACTORY GLUE MARUE LIE, VIA A SPECIALIZED NETWORK THAT FORM ELECTRICAL SYNAPSE SIS WITH PRINCIPLE NEURONS AND IN THE SECOND PART OF THE TALK, I WILL SHOW YOU EVIDENCE THAT THESE ELECTRICAL CONNECTIONS ARE POTENTIATED WHEN SENTENCERY AFROBS ARE REMOVED FROM A SUBSET OF GLUE MAR LIE. NOW IN ORDER TO SET UP THE STUDIES I WILL TELL YOU ABOUT TODAY AND BOTH OF THESE REPRESENT PRETTY RECENT WORK FROM THE LAB, I WILL TELL YOU ABOUT OLDER WORK. I WILL TELL YOU ANY AN EXPERIMENT WE DID, THAT SUGGESTED TO US, THAT THERE EXISTS BOTH INHIBITORY AND EXCITATORY LOCAL INPUT TO A-10A LOBE PROJECTION NEURONS OR PIONS. SO THE RATIONAL BEHIND THIS EXPERIMENT WAS WE THOUGHT THAT WE COULD VISUALIZE THE LOCAL INPUT TO A PION BY REMOVING DIRECT INPUT THAT, IS PREVENTING COGNATE ORONS FROM RESPONDING TO ODORS AND SO WHAT WE DID WAS TO COVER THE MAXILLARY PALP WITH SORT OF A NONTOXIC PLASTIC SHIELD. WE ACTUALLY JUST COATED IT WITH EPOXY, THE EPOXY RISE INTO A NICE, HARD, SHELL, IT'S A TIGHT SHELL, TURNS OUT THEY DON'T REFOND ODORS UNDER THESE CONDITIONS AND WE RECORD FROM A PROJECTION NEURON WHICH IS LABELED WITH GFP, SO IDENTIFIED AND IT'S POST SYNAPTIC TO A P A LP GLUE MARIOUS AND THIS WE CONTINUE TO OBSERVE NORMAL SPONTANEOUS LARGE EPSPs, SUGGESTING THE ORONS ARE CONTINUING TO FIRE SPONTANEOUSLY WITHIN THEIR SHELL. BUT, NORMAL ODOR RESPONSES, ARE GONE. SO, IF WE APPLY AN ODOR THAT NORMALLY DRIVES THESE OONS VERY STRONGLY WE JUST DON'T SO A STRONG RESPONSE, SO WE DID THEN WAS TO APPLY ODORS TO THE A-10A AND WE REASONED THAD ANYTHING WE SAW IN THIS PION SHOULD REFLECT LATERAL INPUT FROM THE ANTENNA GLUMARILY, AND WE SAW UNDER THESE CONDITIONS ODOR CAUSED SPONTANEOUS ACTIVITY TO BE SUPPRESSED AND THE MEMORY POTENTIAL TO BE HYPER POLARIZED AND THAT IS THE EXISTENCE INHIBITORY INTERACTIONS BETWEEN GLUE MAR ILLEGALSY AND AND WE OFTEN DID THE EXPERIMENT ANOTHER WAY AND INSTEAD OF SHIELDING, AND WE REMOVE THE PALP BEFORE THE EXPERIMENT, AND, AND THESE ODORS BEFORE, WE'RE REPORTING FROM THE EXACT SAME TYPE AS BEFORE, AND IN THIS CASE, WE SEE NO SPONTANEOUS ACTIVITY THAT MAKES SENSE BECAUSE IT'S COGNATE ORONS, THAT ARE GONE, BUT HERE WE SEE ODOR DEPOLE AND IT SUGGESTED TO US AND IT'S INHIBITORY ACTION, AND IN THIS EXCITATION IN THIS CASE, AND IT'S IN HERE, THE HALF, AND AND SO, I'M GOING TO SUMMARIZE IN 1 SLIDE, AND WE FOUND THE LATERAL INHIBITION IN THE CIRCUIT IS PRIMARILY, NOT STRICTLY BUT PRIMARILY ACTING AT A PRESYNAPTIC LOCUST, SO SOME NEURONS, I'LL CALL THEM FOR ILNS FOR INHIBITORY LOCAL NEURONS, THEY ARE ACTINGOT PRESYNAPTIC NUDGEONS. SO THESE ARE GABAMINERGICKIC, SO THESE ARE SUPPRESSING RELEASE FROM THESE, AND MEAN WHILE, WE HYPOTHESIZE THERE EXISTS EXCITATORY LOCAL NEURONS THAT ARE ACTING ON THE PION DENDRITIC DENDRIT E. SO THE IDEA WAS THAT PRESYNAPTIC INHIBITION, IS ONLY GOING TO BE VISIBLE IF THE ORONS ARE RELEASING NEUROTRANSMITTER WHEREAS POST INAPTIC EXITATION ISA ALWAYS AND IT TURNS OUT THESE ARE CORRECT AND THAT MORE OVER WE COULD CHARACTERIZE THE THIS SHAPES AND AND IF WE STIMULATE 1 SELECTSIVELY WITH AN ODOR THAT'S SELECTIVE FOR THAT ORON TYPE AND WE PLOT P-AND FIRING RATE VERSES ORON FIRING RATE FOR THAT GLUE MARIOUS WE SAW STEEP RELATIONSHIPS THAT SATURATE EASILY. BUT IF WE THEN DROVE THE ENTIRE NETWORK DRIVING ACTIVITY, WITH THE NEURONS IN AND IT BECAME MORE SHALLOW AND HARDER TO SATURATE THE THE PION, SO THIS IS THE HALLMARK OF ADJUSTABLE GAIN CONTROL IN THE CIRCUIT AND IMPORTANTLY, THE MAGNITUDE OF INHIBITION WE SAW HERE, ARE GROWING MORE OR LESS LINEARLY WITH TOTAL ACTIVITY AS THIS CARTOON INDICATES AND THIS IS ABLE TO ADJUST THE STRENGTH OF ORON SYNAPSE SIS AND THUS THE STEEPNESS OF THIS TRANSFORMATION AND THE FUNCTION OF TOTAL INPUT TO THE NETWORK. NOW THESE STUDIES HOWEVER, LEFT SOME--UNANSWERED QUESTIONS THAT WE THOUGHT WERE INTERESTING. YOU NOTICE I HAVEN'T TALKED VERY MUCH ABOUT THESE ELNs, THEY WERE A HYPOTHETICAL CONSTRUCT FOR US, WE DIDN'T KNOW WHAT NEURONS THESE MIGHT BE, WHAT THE CELLULAR SUBSTRATE OF THESE MIGHT BE. SO EMBARKING ON THE STUDY I'M ABOUT TO TELL YOU ABOUT, WE STARTED OUT WITH THE COUPLE OF KEY QUESTIONS, FIRST, HOW DO ELNs EXCITE PIONS AND BROADLY WHY MIGHT THEY BE A USEFUL FOR FOR THIS CIRCUIT TO HAVE AND I THINK THE ANSWER IS NOT OBVIOUS. SO, IN EMBARK O GBA THIS STUDY, WE'RE FRUSTRATED BECAUSE WE IN NO GENETIC DRIVER LINE, THAT WAS SPECIFIC FOR WHAT WE THOUGHT WAS A GOOD CANDIDATE POPULATION OF ELNs, SO OUR LAB AND OTHER LABS HAD NOTICED THAT WHEREAS MOST INTERNORONS ARE GABBA POSITIVE THERE'S A POPULATION THAT IMMUNO NEGATIVE AND YOU'RE LAB POINTED OUT THAT MOST OF THESE ARE IMMUNO POSITIVE FOR A COLON TRANSFIR ACE. AND THESE ARE ELNs AND HALF OF THEM WERE NEGAATIVE, AND AND IT'S A MIXED POPULATION AND SO HERE WE HAVE A RECORD TAG'S A CHANNEL REDOPSIN AND THE LIGHT POLARIZES THE CELL AND WE WANT TO USE THIS TOOL TO SAY, IS IT POSSIBLE FOR THIS POPULATION TO EXCITE PMs. SO HERE WE'RE RECORD PROGRESS A PM STIMULATING THAT OR MIXED POPULATION AND WHAT WE SEE ON AVERAGE IS EXITATION FOLLOWED BY INHIBITION AND THE MOST BASIC THING YOU CAN DO WHEN YOU CHARACTERIZE A SYNAPTIC CONNECTION IS TO VERIFY IT'S BLOCKED BY BLOCKING SORT OF CHEMICAL SYNAPTIC TRANSMISSION AND SO WE APPLIED CABMIUM WHICH IS A ANOTHER AND SHOULD BLOCK VESICLE RELEASE AND WE VERIFIED OTHER EXPERIMENTS AND WHAT WE FOUND IS THAT CABMIUM BLOCKED THE THE POMMENNENT AND THE EXCITE ATATORY AND BY SUBTRACTION IT HAD A SENSITIVE COMPONENT AND LOWER COMPARED TO THE CABMIUM COMPONENT. AND COMPARATIVELY FASTER, SO THIS SUGGESTED THAT THE MECHANISM HAD A CELLULAR AND SYNAPTIC LEVEL OF LATERAL EXCITATION MIGHTnw p BE UNUSUAL. SO TO CHARACTERIZE THESE CONNECTIONS IN MORE DETAIL, WE WENT TO A MORE OLD FASHIONED APPROACH WHICH IS PAIRED RECORDINGS. AND WE MADE SIMULTANEOUS RECORDINGS HERE AGAIN TARGETING GFP LABELED IN THIS MIXED POPULATION AND WE SAW 2 KINDS OF CONNECTIONS. SO THESE ARE BOTH CURRENT CLAMP RECORDINGS AND WE'RE STIMULATING WITH CURRENT INJECTION, RECORD FROM A PN AND THIS THIS EXAMPLE, CURRENT INJECTION WHICH PRODUCES A TRAIN OF SPIKES IN IN LN, THIS TURNS OUT TO DEPOLARIZE THE SIMULTANEOUS RECORDED, WHEREAS IN THIS EXAMPLE, THE RESULT IS A HYPER POLARIZATION OF THE PN AND IT SHOWS THAT INDIVIDUAL LNs WITHIN THIS MIXED POPULATION HAVE EXCITATORY OR INHIBITORY AFFECTS AND THEY HAVE PROPERTIES THAT ALLOWED US AND UNEQUIVOCALLY. AND WITH THESE SYNAPSE SIS IN DETAIL, TO ASK WHAT THEY WERE LIKE. SO HERE AGAIN WE STIMULATING THE THE CURRENT INJECTION RECORDS FROM THE PN, WE FOUND WHEN THE LN IS DEON POLARIZED AND THEY SHOWED YOU BEFORE AND WHEN HAD THIS LNIS HYPER POLARIZED THE PN IS HYPER POLARIZED. AND NONE OF THIS WAS RESPONSE AND THAT'S JUST BECAUSE THE PRESYNAPTIC CELL IN THIS CASE IS FIRING MORE SPIKES. IT'S DISINHIBITED IN CABMIUM. THIS IS 1 EXAMPLE, HERE'S A GROUP DATA, WE QUANTIFY THIS BY MEASURING THE CO EFFICIENT AND THAT'S THE POST SYNAPTIC CHANGE, AND YOU CAN SEE, IN THE AGGREGATE. AND IT'S TAKEN TOGETHER, IT'S HALLMARKS OF THE PURELY ELECTRICAL CONNECTIONS. IT SUGGESTED TO US THAT THE CONNECTION FROM THE ELNs TO THE PIONS WAS AN ELECTRICAL SYNAPSE RATTLER THAN A COLONERGIC RESPONSE AT THE OUTSET OF THE STUDY. AND THESE COULD BE GENETIC AND IT'S IN A GENE CALLED SHAKE B WHICH HAD--WOULD BE A CONSTITUENT TO GAP JUNCTION AND IT'S REQUIRED FOR THE FORMATION OF CERTAIN ELECTRICAL SYNAPSE SIS IN THE THE INDIVIDUAL OF THE FLY, SO WE ASKED, THE MUTANT WHAT THESE CONNECTIONS WERE DOING. AND IT WAS IN THE SHAPE OF A MUTANT SUGGESTING THAT THE SHAKE B MUTANT WAS A CONSTITUENT OF THESE ELECTRICAL CONNECTIONS AND BECAUSE WE HAVE THESE RECORDINGS, WE CAN LOOK AT TRANSMISSION EITHER FROM E LM, AND IT SUGGESTS THAT AN ELECTRICAL CONNECTION, IT WOULD MAKE SENSE THAT THE CONNECTIONS ARE BI-DIRECTIONAL, AND IN THIS CASE, STAFF APPLICATION OF CABMIUM SUBSTANTIALLY ATTENUATE ALTHOUGH IT DIDN'T BLOCK THE RESPONSE TO DEPOLARIZATION AND YOU SEE THIS HERE IN THE GROUP DATA. ARGUING THAT THIS CONNECTION CONSISTS OF A MIXED CHEMICAL ELECTRICAL SYNAPSE, THIS IS NOT TOO SURPRISING BECAUSE IT WAS ALREADY KNOWN THAT PIONS CAN RELEASE A, AFETAL CO LINE FROM THEIR DENDRITE. IN THE SHAKE B MUTANT WE SAW THAT THE PN RESPONSE OF THE ELN TO HYPER POLARIZATION OF THE PRESYNAPTIC CELL, THE PION WAS ABOLISHED BUT THE RESPONSE TO DEPOLARIZATION OF THE CELL WAS NOT ABOLISHED, AND THIS IS MORE OR LESS THAN YOU WOULD EXPECT IF THE MUTATION ABOLISHED THE ELECTRICAL COMPONENT OF THIS CONNECTION WHILE LEAVING THE CHEMICAL COMPONENT UNAFFECTED. SO, WE ALSO ASKED WHETHER OR NOT ELNs FORM SYNAPSE SIS WITHIN INHIBITORY AND GABAMINERGICKIC ELNs AND THEY DOE, SO THIS IS A DUAL RECORDING AGAIN THESE TYPES HAVE INTRINSIC PROPERTY SO WE CAN TELL THEM APART EASILY AND WHAT WE SAW HERE IS THAT HYPER POLARIZING THE ELN, HYPER POLARIZED THE ILN, SUGGESTED OF AN ELECTRICAL CONNECTION, DEPOLARIZATION OF IT PRODUCES QUITE A LARGE DEPOLARIZATION OF THE ILN AND THIS IS SUBSTANTIALLY ATTENUATE BIDE CABMIUM SUGGESTIVE OF AGAIN A MIXED SYNAPSE HERE FROM THE EXCITATORY SYNAPSE ON TO THE LOCAL NEURON AND THAT'S INTERESTING BECAUSE IT'S SUGGESTS THAT ELNs FORM PURELY ELECTRICAL SYNAPSES BUT MIXED CHEMICAL SYNAPSE SIS WITH GABBAERGIC INTERNEURONS. IT'S AN INTERESTING FORM OF SPECIFICITY. IN THIS CASE, THE RESULTS WITH THE SHAKE B MUSEUMITANT WERE MORE COMPLICATED HERE WE SEE THE SHAKE B MUTANT COPE PLETELY ABOLISHS ALL THE RESPONSE OF THE ILN. SO BOTH THE ELECTRICAL AND THE CHEMICAL COMPONENT SUGGESTING THAT THE ELECTRICAL SYNAPSE IS REQUIRED DURING THE FORMATION OF THE CHEMICAL COMPONENT. THIS PHENOMENON HAS BEEN SHOWN PREVIOUSLY IN OTHER SYSTEMS, BUT IT SUGGESTS A GENERAL CAVEAT IN THE INTERPRETATION OF THIS TYPE OF MANIPULATION. SO JUST TO SUMMARIZE WHAT I TOLD YOU SO FAR. IT'S A BIT COMPLICATED. WE SEE THAT--WHOOPS. ELNs MAKE ELECTRICAL SYNAPSE SIS ON PNs AND PIONS MAKE MIXED ELECTRICAL COMPLEXES BACK ON TO ELNs. SO THESE SYNAPSES ARE ASSIMET RAKE IN THIS SENSE WE'VE ALWAYS SEEN EVIDENCE THAT ELNs MAKE MIXED CHEMICAL ELECTRICAL SYNAPSE SIS ON TO ILNs AND THESE ILNs SEEM TO POTENTLY INHIBIT AXON TERMINALS. ALL RIGHT, SO AT THIS POINT, IT SEEMED TO US(2sñ THAT THESE SO CALLED ELNs, THESE EXCITATORY INTERNEURONS THAT FORM ELECTRICAL SYNAPSE SIS WITH PNs AND ILNs WERE A GOOD WAY TO CANDIDATE FOR THE CELLULAR SUBSTRATE OF OF THIS PHENOMENON THAT WE'RE CALLING LATERAL EXPECTATION. SO IF THAT'S TRUE, SINCE WE'VE SEEN THE MUTATION DISRUPTS THESE CONNECTIONS THEN WE WOULD PREDICT THAT THE SHAKING MUTATION SHOULD ALSO DISRUPT ODARE OF LATERAL EXCITATION AND IT TURNS OUT THAT THAT'S TRUE, HERE WE'RE JUST RECORD PROGRESS A PN, POST SYNAPTIC TO A GLUMARIUS, SO WITH THE AN FENNA WHICH ODORS, AND IN GENERAL WE SEE THE THE AND IN THE SHAKE BM UITANTS A LATERAL EXCITE ABLE WAS AND IT WAS MEDIATED BY THE ILN NETWORK AND NOW THE BIG QUESTION IS SO WHAT. DOES THIS NETWORK HAVE ANY IMPACT ON PNs SPIKING RESPONSES TO ODORS, BECAUSE THESE ARE THE ONLY SIGNALS THAT LEAVE THE LOBE. THESE ARE SENT TO HIGHER BRAIN REGIONS. YOU MIGHT HAVE NOTICE THAD THESE ARE GENERALLY RATHER WEAK. AND SO, WE THOUGHT IT WAS POSSIBLE THAT DISRUPTING THE NETWORK MIGHT HAVE ACTUALLY NO DISCERNIBLE EFFECTOT ORDER EVOKED SPIKING ACTIVITY OF PNs. SO IT WOULD REST THIS, RECORDED FROM AGAIN GENETICALLY LABELED PNs AND DEFINED GLUMARILY, AND WE ASK HOW THEY'RE RESPONSENESS MIGHT DIFFER. AND A VARIETY OF CASES WE SAW THAT ELIMIN 8ING LATERAL--ELIMINATING THE LATERAL EXCITATION WE SAW ODOR RESPONSES. WE EXPECT AS YOU MIGHT AT FIRST GLANCE REMOVING THE CELLS. WE'RE RECORDING THE PALP PN AND I'M SHOWING YOU REPRESENTATIVE EXAMPLES OF ODOR RESPONSES, AGAIN AVERAGED ACROSS MANY EXPERIMENTS SO MEAN PLUS OR MINUS STANDARD AIR, I'M SHOWING YOU RESPONSES TO WHAT HAPPENS TO BE 3 DIFFERENT CONCENTRATIONS OF THE SAME ODOR AND YOU CAN SEE THAT IN THE SHAKE B MUTANT THESE RESPONSES ARE MODESTLY BUT SIGNIFICANTLY WEAKER THAN IN WILD-TYPE. SO WE WANTED TO KNOW, DOES THIS REALLY REFLECT THE LOTERAL LOSS, AND YOU MIGHT EXPECT THAT ALL KINDS OF THINGS ARE ABERRANT SO WE DID A VARIETY OF CONTROL LOOKS NORMAL IN THE MUSEUMITANT AND THAT SYNAPSES ARE NORMAL AND SIN SAPS TWOS BETWEEN THEM ARE NORMAL. BUT WE ALSO REELED WE COULD DO ANOTHER CONTROL EXPERIMENT, A PREDICTION HERE IS THAT IF THIS PHENOTYPE REFLECTS A LOSS OF LATERAL EXCITATION, THEN THE PHENOTYPE SHOULD GO AWAY IN A CONTEXT WHERE THE NETWORK AS A WHOLE, LATERAL INTERACTIONS IN GENERAL ARE MAKING A MINIMAL CONTRIBUTION TO THE PN ODOR RESPONSE. WE TOOK ADVANTAGE OF THE FACT THAT IT'S RECORDING OF THE PN, WE REMOVE THE ANTENNA BEFORE THE EXPERIMENT AND IN THIS CASE, THE DIRECT FEED FORWARD AND PUT INTACT BUT BECAUSE 90% OF ORONS RECITE IN THE ANTENNA, 90% OF INPUT INTO THE NETWORK IS ABSENT AND THUS THE THE ODOR RESPONSES SHOULD BE MORE OR LESS DO PURELY 2 OR 3 FORWARD INPUT SO ESSENTIALLY TRYING TO MINIMIZE THE CONTRIBUTION OF THE NETWORK THING, MINIMIZE THE CONTRIBUTION OF LATERAL INHIBITION IS IN THIS CASE, WE'REú  RECORDING AGAIN THE ODOR, YOU ALSO NOTICE THAT THESE RESPONSES TEND TO BE LARGER THAN THESE RESPONSES AND THAT MAKES SENSE BECAUSE AS YOU'VE SEEN, THE NETEFFECT OF THESE INHIBITORY OF THE CIRCUIT--AND IN AKIGZ TO REMOVING A MODEST, SIGNIFICANT SOURCE OF ADAPTATION TO SHE'S CELLS. SO THIS IS THE KIND OF PHENOTYPE THAT 1 PROMOTIONAL MOST WOULD EXPECT AND SO WE TOSSED EXAMPLES OF THE OBSERVATION THAT ELIMINATING STRENGTH AND ODOR RESPONSES SO THIS IS THE CONTEXT OF DIFFERENT ODORS AND GLUMARILY, IN THIS CASE, I'M SHOWING THE RESPONSE OF 1 PION TYPE AVERAGE ACROSS EXPERIMENTS TO 4 DIFFERENT STIMULI. ODOR 1 AND ODOR TO, WHERE ODOR 2 IS PRESENTED AT 3 DIFFERENT CONSITATION--CONCENTRATIONS AND YOU'LL NOTICE THAT IN THE FIRST CASE, THE MUTATION DIMINISHES THE RESPONSE TO THE ODOR, BUT IN THESE 3 CASES IN THE MUTANT, THE ODOR RESPONSE IS LARGER THAN NORMAL. SO WE'RE INITIALLY A BIT PERPLEXED ABOUT THIS ACTUALLY, BUT THINKING ABOUT IT MORE, WE REALIZED THAT BECAUSE THESE EXCITATORY LOCAL INTERNEURONS MAKE PRETTY POTENT SYNAPSE SIS WITH INTERNEURONS BUT THIS MIGHT REFLECT A DEFICIT OF GABAergic DEFINITION AND THERE'S ALWAYS A RECRUITMENT PLAY OF EXPECTATION AND INHIBITION. IF THAT'S THE EXPLANATION OF THE PHENOTYPE AND THIS MAKES PREDICTIONS, FIRST OF ALL WE SHOULD SEE EVIDENCE OF A ROLE FOR GABAergic INHIBITION IN THE THE ODOR RESPONSES IN THE SENSE THAT WHEN WE APPLY THE ANTAGONIST, THESE SHOULD BE POTENTIATED AND SECOND IF THERE'S A DEFICIT IN THE RECRUITMENT OF THE INHIBITION IN THE MUSEUMITANT COPE PAIRED TO WILD-TYPE THAN THE EFFECT OF ANTAGONIST IN BE SMALLER IN THE MUTANT COMPARED TO WILD-TYPE. WE FOUND A NEED THAT APPLYING GABBA RECEPTOR ANTAGONIST WITH THESE RESPONSES CONSIST EPT WITH THE ROLE IN MODULATING THESE RESPONSES. AND IF WE REPEATED THIS EXPERIMENT IN THE MUSEUMITANT, WE SAW THAT THE DISINHIBITTORY EFFECT OF THE ANTAGONIST WAS SUBSTANTIALLY SMALLER, SIGNIFICANTLY SMALLER THAN WHILED TYPE, WITH THE IDEA THAT THERE'S RECRUITMENT OF GAB KACCT MINERGIC DEFINITION. SO JUST TO SUMMARIZE WHAT I TOLD YOU, AND TRY7s TO SUGGEST POETIC TECTIAL FUNCTIONAL--POTENTIAL FUNCTIONAL CONSEQUENCES FOR THESE NETWORK ISHT ACTIONS WE'VE SEEN THERE'S VARIETY OF COMPLICATED INTERACTIONS BETWEEN PRINCIPLE NEURONS AND LOCAL NEURONS IN THE CIRCUIT I'LL BREAK THIS DOWN. SO, OLFACTION BEGINS IN THE CNS WHEN ORONS RELEASE THE TRANSMITTER INTO THE GLUE MAR ILLEGALSOUS, AND THAT ACTS ON PIONS AND THAT SPREADS FROM PIONS TO EONS AND IT THE ELNs THEN RELAY THE EXPECTATION ON THE GLUMARILY, THAT WERE STIMUMENTED OR NOT STIMULATED SO MUCH BY VIRTUE OF THESE PURELY ELECTRICAL CONNECTIONS FROM ELNs ON TO PLNs. SO WHY MIGHT THIS BE USEFUL? WELL, THIS IS VERY SPECULATIVE, BUT WE CONJECTURE THAT PERHAPS THE ELN NETWORK MAY BOOSTf SENSITIVITY TO WEAK ODORS, WHAT'S ANYTHING ON HERE IS THAT PIONS THAT NORMALLY MAY NOT HAVE BEEN MUCH EXCITED BY THE ODOR ARE NOT MOW MORE EXCITED BYIT VIRTUE OF THE FACT THAT THEY'RE SEEING A BIT OF EXCITATORY ACTIVITY THAT'S RELAY FRIDAY ACTIVE GLUE MAR ILLEGALS I AND THAT MEANS THAT PICIOUSONS THAT WERE THRESH HOLD MIGHT BE MORE SUPERTHRESH HOLD AND MIGHT THEN BE RECRUITED INTO THE ONSEMBLE OF RESPONDING NEURONS. THE AND THAT MIGHT BE MORE USEFUL IN MAKING A WEAK ODOR SAY DETECTABLE TO THE ORGANISM. YOU LOOK AT THIS AND YOU MY SAY WELL THAT'S A VERY TINGEEROUS THING TO DO, FIRST OF ALL YOU MIGHT ABOLISH THE ODOR SELECTIVITY OF THESE PICIOUSONS BUT THAT DOESN'T HAPPEN. THESE ARE ODOR SELECTIVE IN SPITE OF THE NETWORK, AND WE THINK THAT'S IN PART BECAUSE THESE CONNECTIONS ARE RELATIVELY WEAK SO THEY'RE MAKING A MODEST CONTRIBUTION TO THE RESPONSE OVERALL. SO I THINK IT'S ALSO NOTABLE THAT THESE CONNECTIONS ARE PURELYQ%X ELECTRICAL, THAT IS CONNECTS FROM ELNs ON TO PIONS, WHY MIGHT THAT BE RELEVANT. WELL, AGAIN THIS IS BUT KEEP IN MIND THAT YOU KNOW A BASIC PROPER OF ELECTRICAL CONNECTIONS AS CHEMICAL CONNECTIONS ARE REDISTRIBUTED. THEY DON'T CONNECT INTO NEW NETWORK, THEY SHUNT TO MORE EXCITED CELLS ON TO LESS EXCITED CELLS. AND THUS, THESE ACTIVITIES PURLY ELECTRICAL CONNECTIONS MAY BE 1 REASON WHY THIS NETWORK DOESN'T FALL PREY TO RUN AWAY EXITATION. IT'S A MORE CONSERVATIVE MECHANISM FOR CREATING THESE LATERALS. WE ALSO SAW EVES THAT ELNs RECRUIT ILNs INTO THE THE NETWORK AND WE THINK THEY MAY HELP RECRUIT GAIN CONTROL BY GABAergic INHIBITION AND WE THEN FUNCTION MIGHT BE COMPARATIVELYn MOST IMPORTANT WHEN ODOR STIMULI ARE INTENSE AND WHEN GAIN CONTROL NEEDS TO BE TURNED UP. SO NOW I'M MOVING ON TO THE SECOND PORTION OF MY TALK AND I'M GOING TO SHOW YOU EVIDENCE THAT THESE ELECTRICAL CONNECTIONS ARE POTENTIATED WHEN SENSORY A41S ARE REMOVE FRIDAY A SET OF GLUE MAR LIE SO THE WAY WE FIRST NOTICED THIS WAS AN EXPERIMENT LIKE THIS. HERE WE'RE RECORD PROGRESS A PION THAT HAPPENS TO BE POST SYNAPTIC AND WE REMOVE THE A-10A ACUTELY AND WHAT YOU SEE IS YOU'VE SEEN BEFORE IS AT THE PION IS DEPOLARIZED MODESTLY BY THE ODOR REFLECTING LATERAL EXCITATION, WE KNOW THROUGH THE THE E LN NETWORK. BUT IF WE REMOVE THE ANTENNA, PRIOR TO THE RECORDING, WE KNOW THAT THESE TERMINALS DEGENERATE FROM THE BASIS OF OTHER INVESTIGATORS WORK SO IN THAT CARTOON I'M SURE NOW THESE TERMINALS ARE ABSENT FWE NOW RECORD FROM THE SAME PLN, WHAT WE SEE A VERY SUBSTANTIAL DIFFERENTIATION IN THE LATERAL EXCITATION AND YOU KNOW I'VE BEEN IN LTP LABS, STUDIES PLASTICITY, SEEN PLAST ISOTOPITY. THIS IS LIKE THE LARGEST EFFECT IN NEUROSCIENCE, IN MY HANDS. LIKE THIS IS REALLY LARGE, REALLY RELIABLE. HERE'S 1 EXPERIMENT, AND YOU CAN SEE HERE JUST THIS MASSIVE POTENTIATION OF ACTIVITY, AND HERE'S A SEGMENT OF PROJECTION NEURONS OR PIONS SPAINIOUS ACTIVITY SORT OF BISE LINE ACTIVITY IN THE ABSENCE OF ODOR AND YOU'LL NOTICE ALSO THAT IN THE CHRONIC DEA41ATION CASE, THERE'S A POTENTIATION OF THE MEMORY POTENTIAL, SUGGEST OF OF INCREASED SYNAPTIC INPUT TO THE CELL AND HERE'S GROUP DATA SHOWING YOU ON AVERAGE A VERY SUBSTANTIAL INCREASE ON THE MAGNITUDE OF ODOR DEPOLARIZATION AND ALSO AN INCREASE IN THE MAGNITUDE OF THE STANDARD DEVIATION OF THE MEMORY POTENTIAL AND SPONTANEOUS MEMORY POTENTIAL FLUCTUATIONS SO THESE GO HAND IN HAND. WE'RE WE'RE RECORD PROGRESS A PN AND ARE REMOVING THE ANTENNA ACUTELY OR CHRONICALLY. THIS IS NOME NONE IS NOT SPECIFIC TO THE GLUMARILY, SO WE'RE RECORD PROGRESS THE THE TOP, REMOVING THE PALP EITHER ACUTELY OR CHRONICALLY AND WE SEE THE SAME SORT OF THING. SO A SUBSTANTIAL POTENTIATION OF ODOR DEPOLARIZATION AND SPONTANEOUS ACTIVITY TENT QUAGS OF MEMORY AND POTENTIAL FLUCTIATIONS AND HERE'S GRAPE GATTA SHOWING THE MAGNITUDE OF THIS EFFECT. SO WHAT'S GOING ON. WELL WE KNOW BASED ON THE WORK OF OTHER INVESTIGATORS FROM THE LAB, AND THE LAB FOR EXAMPLE, THAT WHEN A GLUMARILUS, IS DEAFFRONTED THAT THE TARGET--THAT THE OTHERS DO NOT INNOVATE THIS REAL ESTATE. SO THEY DON'T SPROD OVER INTO THE DEAFFRONTED, SO WHEN WE DO THOSE LABS TOGETHER THAT WE PUBLISHED FROM, THAT THE DENDRITES IN THESE THE GLUMARILUUS, RESPECT THE BOUNDARIES SO THEY DON'T PREED SOUGHT INTO OTHER GLUMARILY. SO FOR THAT REASON IT DOESN'T SEEM POSSIBLE THAT NEW CONNECTION VS FORMED. RATHER IT LOOKS TRULY LIKE AN INCREASE IN THE AMPLITUDE OF LATERAL EXCITATION. SO WE WONDERED WHETHER OR NOT THESE CONNECTIONS COULD BE POTENTIATED AND SO TO DO THAT WE NEED EXSIGHTATTORY LOCAL NEURONS AND FOR A CASE EITHER THE ANTENNA IS REMOVED ACUTELY OR THE ANTENNA IS REMOVED CHRONICALLY. RECORDS HERE AND IN BOTH CASES WE REMOVE THE PALP, ACUTELY TO COMPLETELY REMOVE SPONTANEOUS OVER AN INPUT INTO THE CIRCUIT, THAT MAKE ITS QUIETER AND IT MAKES THESE CONNECTIONS MORE RESULTS SO WE OBSERVE A POTENTIATION IN THE COUPLING FROM ELNs TO PLNs AND YOU SEE THAT HERE, IN THESE RAW TRACES AND HERE'S GROUP DATA SHARING WITH YOU SUBSTANDPOINTIAL INCREASE IN THE COUPLING CO EFFICIENT OVER ALL IN CHRONIC COMPARED TO ACUTE AN 10AL REMOVAL. SO THIS SHOWS THAT THE FUNCTIONAL STRENGTH OF INTERACTIONS FROM ILNs ON TO PIONs IS INCREASED AFTER CHRONIC DE-AFFRONTATION AND IT'S TEMPTING TO SPECULATE THAT THIS SUGGESTS INCREASE GAPITATIONAL CONDUCT ANTS. WE HAVEN'T SHOWN THIS RIGOROUSLY, BECAUSE THIS IS NOT A VOLTAGE RECORDING. IT'S DIFFICULT TO MAKE REALLY GOOD VOLTAGE CLAMP THIS KNEES SITUATIONS BUT THIS IS AT LEAST CONSISTENT WITH AN INCREASED GAP JUNCTIONAL CONDUCT ANTS. IT'S ALSO CONSISTENT I SHOULD SAY WITH THE CHANGE IN THE ELECTROTONIC PROPERTIES OR THE THE ELN OR PN THAT MAKE ITS EASIER FOR DEPOLARIZATIONS AND HYPER POLARIZEDARRIZATIONS TO PROP GATE BETWEEN THE THE CELL BODY AND THE CYTOCONNECTION BUT I DIDN'T SAY THAT WE SEE ANY CHANGE IN THE INPUT RESISTANCE OF THE CELL WHICH IS IS A WEAK PIECE OF EVIDENCE AGAINST THAT TYPE OF ELECTROTONIC CHANGE SO POSSIBLY A CHANGE IN THE GAP JUNCTION BUT WE HAVEN'T SHOWN THAT RIGOROUSLY WE REALIZED THAT INCREASED LATERAL EXCITATION, IS ELNs WERE MORE ACTIVE IN RESPONSE TO TEST WHETHER OR NOT IT'S TRUE, WE MAKE RECORDINGS FROM ELN, AND, AND AND THEN HERE IN CONTROL, WE PRODUCE A RATHER WEAK DEPOLARIZEITION AND CHRONICALLY REMOVED IT FROM THE SUBSTANTIAL POTENTIATION OF ACTIVITY IN THE CELLS. , AND THIS IS MORE EXCITED RESPOND TO ODORS AFTER THIS PLASTIC ITER HAS BEEN INDUCED. THIS COULD BE SECONDARY TO INCREASED FUNCTIONAL COUPLING BETWEEN PIONS AND ELNs BUT IT COULD REFLECT INDEPENDENT EFFECT. IT MIGHT REFLECT FOR EXAMPLE, FROM ORONS ON TO ELNs AND WE HAVEN'T BEEN ABLE TO ANSWER THIS QUESTION ATvs OçNJbé THIS RAISES THE QUESTION, IS PLASTICITY SPECIFIC TO CHRONICALLY DE-AFFRONT AND GLUMARILYFTHEY'RE MORE EXCITE BIDE ORONS THENNA THAT'S BY DEFINITION NONE SPECIFIC OOSKT. AND THESE ARE ALMOST ALL GLUMARILY, BUT WHAT ABOUT UPREGULATION OF ELNASKS PIONS AND HERE WHAT WE'RE DO SUGGEST REMOVING THEM ACUTELY OR GLUEING CHRONICALLY, RECORDS NOT ONLY WHEREAS BEFORE WE WERE ASSAYING, PIONS AND ASSAYING TOP PIECES AND SO, WE EXPECT TO SEE NOW CHANGE HERE OR HERE BECAUSE THESE PALPIONS ARE NOT IN THE GLUMARILY, AND IN BOTH CASES TO MAKE THE NETWORK QUIET AND WHAT WE OBSERVE IS THAT THERE'S A SUBSTANTIAL INCREASE IN THE COUPLING CO EFFICIENT IN PALP GLUMARLIY, JUST AS IN THE OTHERS THAT IS PRODUCE INDEED THESE SLIDES FOR DATA COMPARISON AND THIS ARGUES THAT THE UPREGULATION OF FUNCTIONAL CONNECTIONS FROM ELNs ON TO PLNs IS NOT PACIFIC SOPHISTICATED DE-AFFRONT AND GLUMARILY, SO IT'S A LESS GLOBAL FETAL COMPARTMENT NONE NONE. SO WHAT SIGNAL INDUCES THIS PLASTICITY. OUR FIRST HYPOTHESIS HERE IS THE LOSS OF ELECTRICAL ACTIVITY PER SE. THAT'S THE CLOSESSIC PARADIGM FOR SENSORY DEPRIVATION, REORGANIZATION OF SENSORY BRAIN REGIONS, SO IN ORDER TO ASK WHETHER OR NOT, SIMPLY, DIMINISHING ODOR EVOKED ACTIVITY WAS SUFFICIENT, WE TOOK ADVANTAGE OF A MUTATION IN AN ODOR RECEPTOR GENE CALLED OR43 B AND WHAT WE REASONED IS THAT, UPREGULATION SHOULD OCCUR IN THE AFFECTED GLUE MAR ILLEGALSOUS IN THE MUTANT IF THE LOSS OF OF ELECTRICAL ACTIVITY WAS SUFFICIENT. HERE WHAT WE'RE DOING IS RECORDING FROM A SPECIFIC TYPE THAT HAPPENS TO BE IN GLUE MARIOUS, IS THE THAT'S POST SYNAPTIC THAT NORMALLY EXPRESS OR43 B. IN THE OTHER EXTERNAL CONFIGURATION, WE'RE WORKING IN FLIES THAT HAVE A NULL MUTATION IN OR43 B, SO THESE ORONS IN THESE FLIES ARE SILENT AND WE SHOW THAT. THEY DON'T RESPOND TO ODORSORS AND THEY HAVE SUBSTANTIALLY REDUCED SPONTANEOUS ACTIVITY. WE'RE REMOVING THE ANTENNA ACUTELY IN BOTH CASES AND STIMMULING WITH POWDERS IN BOTH CASES. SO WE'RE TRYING TO MEASURE LATERAL EXCITATION ON TO THE VNPNASKS WE'RE ASKING WHETHER OR NOT THAT'S LARGER IN THE MUTANT COMPARED TO WILD-TYPE AND TO MAKE A LONG STORY SHORT, THE ANSWER IS NO, THE MAGNITUDE OF EXCITATION IS NOT LARGER, SPONTANEOUS MEMORY FLUCTUATIONS ARE NOT LARGER AND HERE'S GROUP DATA SHOWING YOU NO SIGNIFICANT DEFECT AT ALL - EITHER OF THESE PARAMETERS SO.Y WHAT THIS ARGUES IS THAT THE LOSS OF ELECTRICAL ACTIVITY IS NOT SUFFICIENT TO RINE DUCE PLAST ISOTOPEIT. WE WANTED TO PRESS THIS HARDER SO WE DID ANOTHER GENETIC MAP EPIGENETICCULATION WHICH IS MORE SEVERE THAN THIS. IT TAKE ACE LONG TIME TO EXPLAIN SO WE CAN TELL YOU THE RESULT WHICH IS IN THAT CASE, ALSO, WE SAW NO EVIDENCE THAT THIS TYPE OF PLASTICITY COULD BE INDUCED BY SIMPLY THE LOSS OF ELECTRICAL ACTIVITY IN THESE NEURONS. SO, WE THEN THOUGHT, PERHAPS THE SIGNAT IS NOT DUE TO DIMINISHED ACTIVITY. MAYBE IT HAS TO DO WITH CELL DEATH ITSELF. THAT IS THE ACT OF SEVERE MITRALLERRING THE AXONS OF THE THE PRIMARY SENSORY NEURONS. SO, THIS LED US TO READ LITERATURE ON WHAT HAPPENS WHEN AXONS ARE SEVERED AND IN PARTICULAR THERE'S A LARGE AND ANYTHING LITERATURE ON WHAT HAPPENS IN THE DROSOPHILA ANTENNA LOBE WHEN ORON AXONS ARE SEVERED SO STUDIES FROM A VARIETY OF DIFFERENT LABORATORYS AND PARTICULAR THE LABORATORY OF OF MARK FREEMAN AT U-MASS AND THE LABORATORY AT STANDIFORD DESCRIBED A SERIOUS OF CIRCUITS AND WHAT HAPPENS WHEN THEY'RE CUT. THE AXONS SEEMS TO RESULTS IN A SIGNAL BEING SENT FROM SEVERED AXONS TO GLEEL CELLSA AND IN SPECIFIC A GLASS CALLED INSHEATHING GLUE MARIOUSA THAT WRAPS IT AND DEFINES THE GLUE MARULAR COMPARTMENT. WHAT THE LAB AND THE LAB SHOWED IS THAT, THE GLEEL CELLSA ARE RECRUITED TO EXTEND THEM INTO THE DE-AFFRONTED GLUMARION,S, AND THEY CLEAR THEM FROM THE FAG O SIGNIFYITOSEIS. AND WHAT IT SUGGEST SYSTEM THAT THE--SUGGESTS IS THAT THE ACT OF THE AXON SENDS A SIGNAL TO THE THE REST OF THE NETWORK, IN PARTICULAR THE GLUE MARIOUSA, AND THAT ENTIRE SEQUENCE OF EVENT K'S BE BLOCKED. AND THIS IS A FUNKY CHIMERIC PROTEIN CALLED VALORRIAN DISCIPLINARY GENERATION SLOW. IT'S INITIALLY ISOLATED AS A SPONTANEOUS MUTANT IN MOUSE. WHAT IT CHIMERIC PROM PRIZES AND BEYOND THE SCOPE OF OUR TALK AND HOW IT WORK SYSTEM NOT WELL UNDERSTOOD BUT IN MICE IT BLOCKS THE DEGENERATION AND THESE LABS SHOWED THAT THE SAME THING HAPPENS IN DROSOPHILA SO THEY EXPRESSED THIS NEUROPRODETECTEDDIVE GENE, SPECIFICALLY IN ORONS AND IN THIS CASE, IF YOU SEVERE SEVERE MITRALLER THE AXONS, YOU FIND THE AXON STUMPS, THEY CONTINUE TO SIT IN THE GLUE MAR ILLEGALSOUS AND LOOK NORMAL FOR MONTHS. I BEING IT'S REALLY STRIKING. I HEARD THE GENERATEDERATION IS NOT JUST DUE TO LIKE LOSING YOUR LIVE LINE, LOSING YAP CELL BODY, THE SEVERED AXONS NEED TO SIGNAL THE THE GLEEL CELLSA TO CLEAR THEM AWAY. RIGHT? SO WHAT WE WANT TO KNOW THEN IS WHETHER WE COULD BLOCK OUR FORM OF PLASTICITY BY BLOCKING A SIGNAL THAT IS SEVERED AXONS SENDS TO CELLS IN THE CNS. AND SO WE ASKED WHETHER EXPRESSING VALORRIAN DEGENERATION IS ORONS MIGHT BLOCK PLASTICITY. SO HERE WE RECAPITULATING PUBLISHED WORK BY OTHER LABORATORIES. WE'RE EXPRESSING VALORRIAN DEGENERATION SLOW IN ORONS IN CONTROL FLIES BEEN RESPORTED THAT ORON AXON DEGENERATE. ONCE THEY'RE SEVERED THEY DON'T DEGENERATE AND IT'S SLOW DEGENERATION AND HERE CONFOCAL PROJECTION SHOWING THAT RESULT AGAIN IN OUR HANDS HERE WE REMOVE THE ANTENNA, MOST ARE IN TUNNELS SO THAT GFP EXPRESSING AXONS HAVE DISAPPEARED FROM THE MOST OF THE GLUMARLILY, AND A PEER IN THE THE INTERNAL NERVE SIZE OR IN THE EXPRESS DEGENERATION SLOW UNDER PAN O AND DRIVER, WE SEE THAT THEY'RE HERE BROADLY INNOVATED BY GFP POSITIVEAXONS, EVEN SEVERAL DAYS AFTER THE ANTENNA HAS BEEN SEVERED. SO THIS IS SHOW THAT THIS MANIPULATION WORKS IN OUR HANDS. THE EXPERIMENT IS TO ASK WHETHER OR NOT PLAST ISOTOPITY IS--PLASTICITY IS DIFFERENT. SO WHAT COMPARED THE LATERAL EXITATION IN CONTROL FLYS AND FLIES FOR ORONS EXPRESSFUL DEGENERATION SLOW. AND WHAT WE SEE IS WHERE IS THE CONTROL SLIDE SHOWS SUBSTANTIAL POETIC AT THE PRESENT TIMEIATION AS NORMAL IN THE SLIDES WHERE ORONS ARE PREVEPTED FROM DEGENERATING, WE SEE NOTICE POTENTIATION AT ALL. RIGHT? AND SO THAT'S VERY SUBSTANTIAL. SO THIS SUGGESTS THAT BLOCKING WHATEVER SIGNAL IS SENT BY DEGENERATING AXONS TO THE CNS, IT'S SUFFICIENT TO BLOCK PLASTICITY. AND WE THEN DECIDED TO TRY ANOTHER MANIPULATION THAT HAS BEEN RESPORTED TO BLOCK THE RECRUELTIMENT OF MARK FREEMAN'S LAB, SHE SHOWED IF YOU EXPRESS A TEMPERATURE SENSITIVE FORM OF DIAMOND, CALLED SHIBERTIUS, IT BLOCKS THE SEVERED AXONS AND YOU CAN SEE THAT IN THIS CARTOON. WE ASKED WHETHER IT BLOCKS THE LATERAL EXCITATION AND WE FOUND INDEED IT DOES. SO IN FLIGHT OF THIS GENOTYPE, IF WE DO EVERYTHING AT 25-DEGREE WHICH IS IS I PERMISSIVE TEMPERATURE AND ISOFORM AND PLAST ISOTOPE LIT IS INDUDEss AS FORM AND YOU SHIFT THEM AND THERE IS 3-DEGREES, IMMEDIATELY AFTER YOU REMOVE THE ANTENNA, YOU INDUCE THE DINA MIN TO MISFOLD, AND THIS PREVENTS THE INDUCTION OF PLASTICITY, AND GROUP DATA SHARING OVER ALL A LACK OF POTENTIATION AND MARK FREEMAN HAS SUGGEST THAD IT ESSENTIALLY BLOCKED THE ENDOCYTOSIS AND IT'S A CELL SURFACE RECEPTOR ON THE GLEEL CELLSA THAT'S IMPORTANT TO TRANSMIT SIGNAL FROM A SEVERED AXONS TO GREEN GREEN GLEEL CELLSA ANDRY CRUIT THEM SO THAT'S WHAT MIGHT BE GOING ON HERE. NOW IN--WITH RESPECT TO RECRUITING GLEEL CELLSA TO THE AXONS, THIS MANIPULATION IS SPECIFIC TO THE ENSHEATHING GLEEL CELLSA, SO IT'S GOING TO MAKE SOMETHING IN ASTRO SIGHTS IT DOESN'T BLOCK THE PH AGOSIITOSEIS WITH THE STUFF, AND IT WE FOUND MORE THAT WE'RE STUDYING AND SO HERE WE'RE BLOCKINGND O SIGNIFYITOSE AND I GUESS AFTER GLEEL C THAN SHEATHING GLEEL CELLS AND WHAT WE SEE IS THAT THE RESTRICTIVE TEMPERATURE WHERE THE DINA MIN IS NOT FUNCTIONAL, WE STILL GET COMPLETELY NORMAL POTENTIATION OF LATERAL EXCITATION. AND HERE'S GROUP DATA SHOWING YOU THAT. THIS BY THE WAY, SERVES AS A CONTROL FOR THE POSSIBILITY THAT REARING FLIES AT THIS ELEVATED TEMPERATURE INTERFERES WITH THIS NONSPECIFICALLY. SO THIS IS SPECIFIC TO ACHIEVING ASTRO SIDIC GLEEL CELLSA INCREASES CONFIDENCE IN THE MANIPULATION. SO JUST TO CLOSE, I WANT TO LEAVE YOU WITH A MODEL GLEEL CELLSAL IRPT ACTION IN--INTERACADEMIESES IN THE CIRCUIT. SO THE THE WORK OF OTHER INVESTIGATORS HAVE SHOWN THAT SENSORY AXONS CAUSES SIGNAL TO BE SENT TO GLEEL CELLSA AND THAT ENSHEATHING GLEEL CELLSA THEN RESPOND BY PH AG OSIITOSING THESEAXONS AND WHAT WE'VE SEWN IS THAT IN THIS STUDY GLEEL CELLSA ARE RECRUIT SIGNAL IN SOME FASHION TO SURVEYS VIVING NEURONS. CENTRAL NEURONS IN THE CIRCUTE TO CAUSE 2 KINDS OF FUNCTIONAL CHANGES IN THE CIRCUIT. UPREGULATION TO PN COUPLING AND AN UPREGULATION IN ODOR EVOKED ELN ACTIVITY. SO, WHY MIGHT BE THIS BE POTENTIALLY USEFUL OR WHAT ARE FUNCTIONAL CONSEQUENCES? LWE'VE SEEN THEN, THAT WHEN ORONS ARE SEVERED ACUTELY, IT'S GOING TO LOSE A LOT OF EXCITATION, YOU'LL SEE THE LATERAL EXCITATION IS VERY WEAK UNDER THESE CONDITIONS. BUT OVER SOMETIME THE STRENGTH OF THESE CONNECTION SYSTEM POTENTIATED SO THAT NOW, PONS IN A DEAFFRONTING GLUE MARIOUS REBANE THE ABILITY TO SPIKE AND IT'S TURNS OUT THAT THERE ODOR IS BROAD AND IT'S NOT NORMAL UNDER THESE COON DITIONS BUT AT LEAST THEY'RE SPIKING AGAIN IN RESPONSE TO ODORS. SO WE SPECULATE THAT POTENTULATING THE CONNECTIONS MAY HELP MAINTAIN APPROPRIATE LEVELS OF INPUT, THE HIGHER BRAIN REGIONS AND THAT CAN BE USEFUL IF A HIGHER BRAIN REGION NEEDS TO SEE MINIMUM LEVEL OF ACTIVITY, FOR MOST GLUE MAR ILLEGALSY, IN ORDER TO BE IN SAN APPROPRIATE OPERATING RANGE OR TO ACHIEVE APPROPRIATE TROPEIC SUPPORT. IT'S ALSO POSSIBLE THAT THIS MECHANISM HAS NO REAL NATURALISTIC FUNCTION IN THE LIFE OF THE FLY BUT WE SRO STUMPBLED UPON A FUNDAMENTAL MECHANISM COME IS COMPARATIVELY MORE IMPORTANT DURING DEVELOPMENT FOR EXAMPLE, OR OTHER KINDS OF TRAUMA. AND THEN MONITOROCULAR PREPRIVATION AND DOMINANCE, EVEN THOUGH IT'S UNNATURAL AND RADICAL MANIPULATION, THESE TYPES OF MANIPULATION IN THIS STUDY I THINK ARE REARLY PRODUCING AN INTERESTING, AND IT'S PHYSICALLY PROVOCATIVE IN A COUPLE RESPECTS, AND THERE'S NOT IN THE LITERATURE OF LONG LASTING POTENTIATION OF ELECTRICAL CONNECTIONS AND SECOND OF ALL, THERE ARE SOME BUT NOT MANY EXAMPLES OF LITERATURE WHERE THERE'S CLEAR AMBIGUATION OF OF LOSS OF ELECTRICAL ACTIVITY VERSES CELL DEATH PER SE, AND IN THIS STUDY BECAUSE WE HAD GENETIC TECHNIQUE THAT ALLOW US TO DISAMBIGUATE THESE BY CREATING UNDEAD SILENT AXONS THAT EXPRESSED VALORRIAN DEGENERATION SLOW, WE CAN SHOW QUICKLY, I THINK THAT THE TRIGGER FOR THESE EVENTS IS THE SEVERE MITRALLERRING OF AXONS PER SE. FINALLY WHEN THE ACTIVITY IN THE NETWORK IS HIGH, WE THINK THAT THE POETIC AT THE PRESENT TIMEIATING ACTIVITY MAY HAVE A DIFFERENT FUNCTIONAL MESSAGE AND THAT IS IT MAY HELP MAINTAIN RECRUITMENT OF GABBAERGIC INHIBITION AND 1 CONSEQUENCE THEN IS THAT 1 PN THAT WOULD BE DISINHIBITED OF THIS CONTEXT BECAUSE IT HAD FALLEN SILENT WOULD NOW SEE INCREASED FUNCTIONAL INHIBITION BECAUSE THIS INHIBITION IS MORE ACTIVE THAN IT WOULD HAVE BEEN. SO I JUST WANT TO CLOSE BY THANKS OUR FELLOW DROSOPHILA PEOPLE WHO ARE HAVE BEEN VERY GENEROUS TO US WITH SHARING REGIONS AND FLY STRAINS THAT MADE THESE STUDIES POSSIBLE AND ALSO TO OUR FUNDING SOURCES, NIDCD AND A BABY GRANT FROM TTSHMI, AND I WANT TO SHOW YOU THE NAMES AND FACES OF ALL THE PEOPLE IN THE LAB RATORSCHEEACH EXPERIMENT, EACH PROJECT IS AN INTELLECTUAL COLLABORATION WITHIN THE LAB SO ALL THESE PEOPLE GET SOME THANKS FOR THE WORK THAT I SHOWED YOU TODAY. BUT THE HANDS OF THIS EXPERIMENT AND MOST OF THE BRAINS ARE REALLY THE WORK OF 2 PEOPLE, EMREIATSY--EMORY YATZEE, AND HECTOKOMORA, AND I'M PROUD TO SAY THAT BOTH THESE GUY HIS THEIR ENLABORATORYS AND EMRASTARTED A LAB RASTART TED A LAB RATORNEUROECTODERMAL BELGIUM AND HOCTO, STARTED HIS LABORATORY AT THE SCIENCE INSTITUTE SO HATS OFF TO BOTH OF THEM. [ APPLAUSE ] I'VE BEEN ASKED TO HAVE YOU SPEAK INTO THE MIKE SO I DON'T HAVE TO REPEAT QUESTIONS. >> I WILL WILL TALK INTO THE MIKE. IT WAS BEAUTIFUL TO SEE THE DETILED DISSECTION, AND ALSO THE OFFER TO INCLUDE CHEMICAL ELECTRICAL SYNAPSIS, GLEEL CELLSA IS REALLY VERY BEAUTIFUL, I HAVE SPECIFIC QUESTIONS ABOUT THE LAST PART OF THE COUPLING THAT I THINK WAS SUPER INTERESTING. SO 1 OF QUIETS I HAVE IS WHAT DO YOU KNOW ABOUT THE COUPLING WITH THE LOCAL INTERNEURONS AND THE INHIBITORY 1S IS THAT ALSO AFFECTED AND ALSO HOW THE TIMING OF THE--OF THIS CHANGES OF THE INVASION OF THE GLEEL CELLSA INTO THE THE GLOMERRIA, HOW THAT TIMING RELATES TO THE CHANGES THAT YOU'RE SEEING. SO THAT INCREASING--THE POTENTIATION IS TRANSIENT OR LONG LASTING AND WHERE YOU'RE LOOKING IN THIS REARRANGEMENT BECAUSE I WONDER HOW MUCH STRUCTURAL CHANGES ON THE NUMBER OF CELLS THAT ARE PARTICIPATE NOTHING THE NETWORK CAN CHANGE FOR THE COUPLING. THAT'S BASICALLY THE WHOLE UNDERLYING QUESTION. >> RIGHT. RIGHT. SO THE FIRST QUESTION WAS WERE ELN SYNAPSES AND GABAMINERGICKIC SEQUENCES POTENTIATED. >> [INDISCERNIBLE] >> AND SO RIGHT. WE HAVEN'T LOOKED AT THAT WHICH I'M ASHAMED TO SEE WE JUST HAVEN'T. SO THIS IS THE THE WORK OF POST DOC WHO IS ABOUT TO LEAVE A LAB AND I SQUEEZED ALL THE BLOOD OUT OF THAT SPONGE I COULD GET. BUT SOMEDAY HE HAD TO LEAVE. I THINK WE'RE VERY INTERESTED IN LOOKING AT THAT IN THE FUTURE. AND AT THE END I SUGGESTED SPECCATIVELY THAT PART OF THE FUNCTIONAL CONSEQUENCE OF THIS MIGHT BE A REBALANCING OF THE RECRUITMENT AND IF THAT'S TRUE, WE SHOULD SEE POETIC AT THE PRESENT TIMEIATED ACTIVITY IN KNEES ELEMENTS. SO THE SECOND QUESTION WAS,--SORRY, THE--HOW. >> HOW ABOUT THE TIMING? >> RIGHT. THE TIME COURSE, WHAT WE KNOW IS THAT THE SUBSTANTIAL PLASTICITY IS INDUCED AFTER 2 DAYS. WE ALSO KNOW FROM THE WORK OF OTHER LABS THAT SUBITANT YALE PH AGOSIITOSEIS IS COMPLETE WITHIN 2 DAYS SO THAT COURSE, THEY ARE SIMILAR, WE HAVE NOT BEEN A DETAILED TIME COURSE OF THIS EFFECT SO WE DON'T KNOW ON A FINER TIME SCALE THAN THAT WHETHER OR NOT, THE TIME COURSE OF MEMBRANE EXTENSION INTO THE GLUE MAR ILLEGALSOUS AND CLEARANCE OF AXON SYSTEM SIMILAR TO OR DIFFERENT FROM THE TIME COURSE OF PLASTICITY. >> [INAUDIBLE RESPONSE FROM AUDIENCE ] >> THE QUESTION IS IS IT REVERSIBLE AND WE VICTORY DONE THAT EXPERIMENT. IT'S MORE EASIER TO DO THESE RECORDINGS IN ELDERLY FLIES, SO 1S THAT ARE MORE THAN A WEEK OLD. AND PEOPLE WHO WORK IN MAMMALIAN BRAIN TYPES WE KNOW THAT'S TRUE, THEY EXPERIENCE THE SAME FETAL PHENOMENON. >> DO THEY ALL REGENERATE? >> SO THE QUESTION IS DO ORONS REGENERATE IN FLIES AS IN MAMMALS. >> AND THE ANSWER IS NO, THERE'S NO EVIDENCE THAT ORONS BORN DURING THE ADULT LIFE, THE LIFE OF THE FLY IS PRETTY SHORT, SO THEY MAKE THE MOST IMPORTANT LIVES WITHIN HOURS AFTER EMERGES FROM THEIR PUPIL CASE. SO EVERYTHING'S VERY ACCELERATED. YEAH. >> [INDISCERNIBLE] >> THAT'S AN INTERESTING QUESTION. SO WE, MOST ORONS IN THE SLIDE PROJECT, BUT THERE'S A SMALL SUBSET OF TYPES, AND PROJECTS UNILATERALLY. SO THAT SETS UP AN INTERESTING EXPERIMENT IN MIRE VIEW. SO WOB THING WE ASK WAS, IF YOU WORK FROM A PN, TO A BILATERAL GLUMARILUS, AND THE ANSWER IS WHAT HAPPENS? WE DON'T KNOW. WE DON'T SEE LATERAL UPREGULATION. SO THERE'S MINIMAL AMOUNT OF CELL DEATH TO TRIGGER THIS PROCESS. SO THEN ANOTHER QUESTION WE ASKED WAS FYOU MOVE 1 ANTENNA, CHRONICALLY, YOUR DE-AFFRONTING HALF OF THE INPUT TO MOST GLUE MAR ILLEGALSY, BUT ALL OF THEM, TO THE SPECIAL 1S SO WHAT HAPPENS THERE? AND WHAT WE FOUND IS THAT LATERAL EXITATION IS NOT UPREGULATE INDEED THAT CASE AND IN THAT GLUE MAR ILLEGALSOUS, EVEN THOUGH IT LOST IT ALL FOR 2 DAYS THERE'S NO UPREGULATION OF THE EXCITATION, SO THERE'S CONNIVITIENT WITH THE UPREGULATION AND IT'S ALL OVER NONE NEUROECTODERMAL NONE NONE. IT'S NOT SELECTIVE TO PARTICULAR GLUMARILQ, THERE'S A PROCESS AND THERE'S MINIMAL LEVEL OF CELL DEATH THAT'S REQUIRED TO TRIGGER THIS PROCESS. >> [INAUDIBLE QUESTION FROM AUDIENCE ] >> SO FIRST QUESTION, RICHARD LOW'S LAB HAS THE MORPHOLOGIES OF INDIVIDUAL LOCAL INTERNEURONS ARE NOT STEREOTYPED, THERE'S SOME SORT OF STOCHASTIC INDIVIDUAL VARIATION WHAT DOES THAT MEAN FOR WHAT WE SEE HERE. BUT WE SEE HERE, I THINK TENDS TO BE A POPULATION RESPONSE AND SO IT'S SOMETHING THAT EFFECTS AND THE INHIGZ AS A WHOLE, SO INDIVIDUAL VARIATION, AND IT MIGHT HAVE A BIG IMPACT OF THE EFFECT OF INHIBITION IS IT WAS SIMILAR TO 2 INDIVIDUALS. SO THAT SAID, YOU KNOW IT'S WOP IS DIFFERENT. EVERY TIME WE DO THIS EXPERIMENT, WE SEE SOMETHING DIFFERENT SNOW 2 SIDS ARE IDENTIFIABLE, SO I LEARNED FROM THE WORK OF EVE MARTYR THAT THESE INDIVIDUAL VARIATIONS CAN BE INTERESTING. WE HAVEN'T ANALYZED OUR DATA THAT WAY AND IN GENERAL, Imxz=ó THINK IT'S QUITE HARD TORE DESIGN EXPERIMENTS THAT DISAMBIGUATES VARIATION OF BIOLOGY FROM DAY-TO-DAY VARIATION AND EXPERIMENTAL ERROR. SO THESE ARE REALLY INTERESTING QUESTIONS BUT IT'S HARD FOR ME TO THINK OF GOOD EXPERIMENTS TO ADDRESS THIS. >> THE QUESTION IS WHAT SIMILARITIES MIGHT BE TO ADAPT GAIN CONTROL AND THE OLFACTORY SYSTEM OR ANTENNA. AND AND WHAT ARE THE BROAD STROKES BETWEEN WHAT WE'RE SEE NOTHING THE ANTENNA LOBE VERSES INLET RETINA, SO IN THE RETINA, WHEN SIGNALS ARE MORE INTENSE YOU SEE THE INHIBITORY GETS LARGER AND DEEPER. SO THERE'S PROGRESSIVE RECRUITMENT OF INHIBITION IS YOU KNOW PART OF THE NETEFFECT OF THIS IS TO DECORALATE THE ACTIVITY OF DIFFERENT RETINAL GANGLION CELLS CELLS AND WE SEE SOMETHING IN BROAD STROKES THAT'S SIMILAR IN THE DROSOPHILA ANTENNA LOBE AND THAT SUGGESTS A BASIC THEME THAT THE IDEA OF THE CONTROL OF PROGRESSION OF ACTIVITY IN DIFFERENT CODING CHANNELS OR ALSO A DISCIPLINARY MINUTION OF TO REACH SATURATION IS WHICH IS A COMMON THEME. THAT BEING SAID, THERE ARE CLEARLY DIFFERENCES IN THE THEY THINGS THESE ARE IMPLEMENTED AND I'M INTEREST INDEED THE DIFFERENCES AS I AM IN THE SIMILARITIES. I THINK WE SHOULD LET OUR SPEAKER GO HAVE LUNCH NOW. THANK YOU. [ APPLAUSE ] >> THANK YOU.