I THINK THIS IS OUR FIRST DIRECTOR'S SEMINAR SERIES IN 2017. AND I'M DELIGHTED THAT OUR FIRST SPEAKER OF THE YEAR, OF THE CALENDAR YEAR, IS VERONICA ALVAREZ. VERONICA GOT HER UNDERGRADUATE AND Ph.D. DEGREES FROM THE UNIVERSITY OF BUENOS AIRES IN ARGENTINA, IN NEUROSCIENCE. AND THEN SHE CAME TO THE U.S., DID A POSTDOC AT THE (INDISCERNIBLE) INSTITUTE IN ARGON HEALTH SCIENCE UNIVERSITY IN PORTLAND AND HARVARD MEDICAL SCHOOL BEFORE BEING RECRUITED TO THE NIAAA AS A TENURE-TRACK INVESTIGATOR, INTO THE LABORATORY OF INTEGRATIVE NEUROSCIENCE. AND SHE DID EXTREMELY WELL, AND WAS TENURED ALMOST TWO YEARS AGO, YEAR-AND-A-HALF AGO OR SO. AND MOST RECENTLY WAS NAMED THE CHIEF OF THE LABORATORY ON NEUROBIOLOGY OF COMPULSIVE BEHAVIORS, AND AS MANY OF YOU KNOW BECAUSE VERONICA HAS TAKEN A LEADERSHIP ROLE IN CHAMPIONING THE CAUSE OF COMPULSIVE DISORDERS AND UNDERSTANDING PATHWAYS AND SYNAPTIC MECHANISMS THAT AFFECT COMPULSIVE BEHAVIOR SUCH AS DRUG ABUSE, AND SHE'S ACTUALLY CONVINCED ME A COUPLE YEARS AGO THIS SHOULD BE A PRIMARY DIRECTION OF THE NEUROSCIENCE RESEARCH AT THE NIH, AND IT IS. AND THERE'S A LARGE COMMUNITY WHO ARE JUST ENTERING THE ROOM AS WE SPEAK, OF PEOPLE WHO ARE INTERESTED IN THESE DISORDERS WHICH AFFECT MILLIONS OF PEOPLE IN THE UNITED STATES AND IN THE WORLD. AND OFFER REALLY PROMISING TARGETS FOR INTERVENTION. NOT ONLY DRUG ABUSE BUT OTHER KINDS OF COMPULSIVE DISORDERS INCLUDING DISORDERS OF APPETITE THAT LEAD TO OBESITY AND MANY REAL SIGNIFICANT MEDICAL PROBLEMS. SO I'M DELIGHTED TO INTRODUCE VERONICA, AND HER TALK TODAY IS"THE SECTION OF NEURONAL CIRCUITS AND SYNAPSES THAT MEDIATE THE EFFECTS OF DRUGS OF ABUSE." VERONICA. >> OKAY. THANK YOU VERY MUCH, MICHAEL. A REALLY NICE INTRODUCTION. I ALSO WANT TO TAKE ADVANTAGE TO THANK YOU FOR COMING, FIRST, BECAUSE I KNOW IT'S VIDEOCAST, BUT IT'S NICE TO SEE YOUR FACES. AND I WANT TO THANK DR. KENERA AND LAVENGER WHO NOMINATED ME FOR THIS INCREDIBLE OPPORTUNITY. I'M VERY EXCITED BECAUSE IT'S A UNIQUE OPPORTUNITY TO PUT TOGETHER SOME OF THE WORK WE'VE BEEN DOING IN THE LAB FOR THE PAST 8 YEARS, AND OF COURSE I'M NOT GOING TO TRY TO TELL YOU EVERYTHING WE'VE DONE, BUT I'M TRYING TO INTEGRATE A COUPLE STUDIES AND TOPICS. SO MY LABORATORY IS INTERESTED ON COMPOSITE BEHAVIORS. DR. GOTTESMAN VERY NICELY EXPLAINED THESE ARE REPETITIVE ACTIONS, MORE ACTIONS THAT ONCE TRIGGERED ARE REALLY HARD TO STOP AND THAT OFTEN INDIVIDUALS FEEL COMPELLED TO PERFORM. AND COMPOSITE BEHAVIORS THAT ARE ACTUALLY SEEN ACROSS SEVERAL NEUROLOGY AND PSYCHIATRIC DISORDERS, ESPECIALLY CHARACTERISTIC OF ADDICTION, AND THAT HAS BEEN THE FOCUS OF OUR LABORATORY FOR THE FIRST 8 YEARS HERE AT THE NIH, AND THE REASON BEING, ONE IS THAT IN THE CASE OF ADDICTION, THESE COMPOSITE BEHAVIORS ARE DIRECTED TOWARD A DRUG SO THEY CAN BE UNDER TRIGGER, THEY CAN BE EASILY STUDIED ON THAT SENSE, BUT MORE IMPORTANTLY, ADDICTION IS ACTUALLY A VERY IMPORTANT DISORDER THAT AFFECTS A LARGE MAJORITY OF INDIVIDUALS IN THE WORLD AND AMERICANS, SO THIS IS DATA FROM THE CENSUS ON THE NATIONAL INSTITUTE THAT DOES THE CENSUS ON SUBSTANCE USE AND ABUSE DISORDERS FROM 2015. IT WAS THE LATEST I COULD FIND, WHERE YOU CAN SEE THAT APPROXIMATELY 10% OF THE POPULATION IN AMERICA ACTUALLY HAS ABUSED ILLICIT DRUGS OVER THE PAST YEAR IN 2014. AND THIS OF COURSE INCLUDES NOW MARIJUANA, THAT MIGHT NOT BE CONSIDERED TOTALLY ILLEGAL, BUT YOU CAN SEE A SIGNIFICANT ABUSE, PERCENT ABUSE OF STIMULANT DRUGS AND ALSO OPIOIDS. AND THEN IF WE CONSIDER ALSO DRUGS THAT ARE SUBSTANCE OF ABUSE BUT THAT ARE LEGAL SUCH AS ALCOHOL, THERE'S ACTUALLY A LARGE MAJORITY OF INDIVIDUALS LIKE ALMOST HALF, 43% OF THE INDIVIDUALS THAT USE ALCOHOL ACTUALLY ABUSE IT AND UNDERGO EPISODES OF BINGE DRINKING, AND 27% OF THEM ARE REPORTED TO HAVE PROBLEMS OF HEAVY ALCOHOL DRINKING. SO THIS IS A DISORDER THAT AFFECTS MILLIONS OF AMERICANS AND I ALSO WANTED TO HIGHLIGHT SOMETHING FROM THE NIDA WEBSITE THAT I FOUND ON MILD SEX DIFFERENCES. FOR INSTANCE, WOMEN ARE LESS LIKELY THAN MEN TO ABUSE PRESCRIPTION PAIN MEDICINES BUT ARE SLIGHTLY MORE LIKELY TO ABUSE SLEEPING MEDICATIONS, AND ALSO WOMEN HAVE A HARDER TIME QUITTING ACTUALLY FROM SMOKING. SO WHILE THERE ARE SOME SEX DIFFERENCES ACTUALLY BOTH WOMEN AND MEN STRUGGLE WITH THIS DISORDER. SO IN OUR LAB WE'VE BEEN ASKING WHAT ARE THE STUDYING COMPOSITE BEHAVIORS OF DRUG ABUSE WITH EMPHASIS ON COCAINE AND ALCOHOL. AND WE'VE BEEN ASKING, TRYING TO UNDERSTAND HOW IS THAT WHEN GIVEN ACCESS TO COCAINE, FOR EXAMPLE, AS I'M GOING TO REFER MOST OF THE TALK ON, SOME INDIVIDUALS CAN ACTUALLY RESTRAIN TAKING BUT OTHERS CANNOT AND THE BEHAVIORS BECOME COMPULSIVE. AND WE HYPOTHESIZE THAT THERE ARE SPECIFIC NEURONAL ADAPTATIONS THAT ARE UNIQUE TO THOSE INDIVIDUALS THAT ARE VULNERABLE TO DEVELOING THESE BEHAVIORS. IN ADDITION TO STUDYING COMPULSIVE BEHAVIORS THE DRUGS HAVE OTHER MULTIPLE ACTIONS AND WE'VE ALSO SPENT CONSIDERABLE RESOURCES AND EFFORT ON TRYING TO UNDERSTAND THE ACUTE EFFECTS OF THE DRUG SO THE EFFECTS THAT ARE SEEN RIGHT AWAY, MAYBE EVEN DURING THE FIRST EXPOSURE TO THE DRUGS OF ABUSE, AND IN THIS CASE OF COCAINE IT'S A STIMULANT DRUG, ENHANCING LOCOMOTOR ACTIVITY, WE'VE BEEN TRYING TO UNDERSTAND HOW THAT HAPPENS. WE'RE ALSO STUDYING HOW A STIMULANT DRUG, BY WHICH STIMULANT DRUGS SUPPRESS APPETITE, HYPOPHAGIA AND INCREASE WATER DRINKING, POLY DESIA AND UNDERSTANDING SEQUENCES OF EXPOSURE, HOW IT IS THAT WE -- WHERE THE SEQUENCE THAT MEDIATES THE LEARNING OF THE TAKING OF THE DRUG, AND FOR THAT WE'RE USING MODELS OF COCAINE ADMINISTRATION, LOOKING AT HOW MICE, WHERE ALL OUR RESEARCH WILL TAKE PLACE, HOW THESE SPECIES SEEK COCAINE AND WHAT HAPPENS ALSO AFTER ABSTINENCE WHEN THE ANIMALS ARE COMPELLED TO RELAPSE. SO WITH THAT SAID, I'D LIKE TO NOW INTRODUCE THE BASIC CIRCUITRIES. THIS IS THE BASAL GANGLIA IS OF COURSE A PART OF THE BRAIN, CLEARLY STRONGLY IMPLICATED IN REGULATING MOTOR ACTIONS, AND REWARD-MOTIVATED BEHAVIORS. AND CORTICAL AREAS ARE ALSO IN PLACE, ESPECIALLY PREFRONTAL CORTEX AND ANTERIOR CINGULATE AND ALWAYS THE FRONT FRONTAL CORTEX AND HIPPOCAMPUS AND LIMBIC STRUCTURES SUCH AS THE AMYGDALA PLAYING A MAIN ROLE THAT PLAY SOME ROLE IN CONTROLLING REWARD-MOTIVATED LEARNING AND THESE ACTIONS. AND THESE REGIONS OF THE BRAIN RECEIVE DENSE INNERVATION FROM THE DOPAMINERGIC SYSTEMS, AND THE SUBSTANTIAL NIGRA THAT SENDS INNERVATION TO THE BASAL GANGLION CIRCUIT AND REGULATE AND CONTROL THE ACTIVITY OF THESE BRAIN REGIONS. SO DOPAMINE IS A MONO MINERGIC NEUROTRANSMITTER IMPLICATED IN SEVERAL IMPORTANT AND CRITICAL FUNCTIONS OF THE BRAIN, AT THE MORE CELLULAR SYNAPTIC LEVEL HAS BEEN KNOWN TO PLAY A VERY IMPORTANT ROLE IN REGULATING SYNAPTIC PLASTICITY SUCH AS LTP AND LTD, STRENGTHENING AND WEAKENING OF SYNAPSES, MORE BEHAVIORAL FUNCTIONAL LEVEL HAS BEEN IMPLICATED IN MOVEMENT, AND CLEAR EVIDENCE OF THIS COMES FROM PARKINSON'S DISORDERS WHERE DOPAMINE IS DEPLETED AND THERE ARE SEVERE MOTOR IMPAIRMENTS. BUT IT'S ALSO IMPLICATED IN MOTIVATION AND EFFORT. IT'S THOUGHT TO BE A REWARDING SIGNAL TO ALSO HAVE BEEN CALLED TO BE A SIGNAL FOR ERROR PREDICTION, AND ALSO TO BE IMPORTANT IN CODING THE VALUE OF PERCEIVED STIMULI. SO LOTS OF CRITICAL IMPORTANT FUNCTIONS. AND THEY ARE MITIGATED BY THE RECEPTORS. THERE ARE FIVE GENES FOR THE DOPAMINE RECEPTORS. D1 THROUGH D5, ALL TRANSMEMBRANE DOMAIN RECEPTOR COUPLED THROUGH G-PROTEIN AND ALSO ARE RESTING. AND THERE ARE MANY CLASSES, THE D1 LIKES TO CLASS SIGNALS THROUGH GS AND D2 SIGNALS TO GI G-PROTEIN. NOW, I WILL MAINLY -- IN THE LAB WE SPENT A LOT OF TIME FOCUSING MAINLY ON THE ACTIONS OF D1 AND D2 RECEPTORS BECAUSE THESE ARE THE RECEPTORS THAT ARE MUCH HIGHLY EXPRESSED WITHIN THE CIRCUIT, ALTHOUGH OTHER RECEPTORS ARE ALSO FOUND IN THE CIRCUITRY. THE D1 AND D2 ARE THE MOST HIGHLY EXPRESSED. AND SPECIFICALLY, I'M GOING TO FOCUS MY TALK ON THE D2 RECEPTORS BECAUSE THAT'S WHERE WE SPEND A LARGE PART OF TIME STUDYING OVER THE PAST EIGHT YEARS, AND THIS IS BECAUSE THERE IS A VERY STRONG EVIDENCE ACTUALLY HERE FROM NIH, THIS IS WORK FROM VOLKOV STUDYING THESE FOR DECADES, HAS SHOWN IN HUMANS THAT ABUSE STIMULANT DRUGS HAVE LOWER LEVELS OF D2 RECEPTOR IN THESE AVAILABILITY OF THE TWO RECEPTORS IN THE STRIATUM, AND THIS IS AN EXAMPLE OF A HEALTHY SUBJECT AND AMPHETAMINE USER IN THIS CASE, AND YOU CAN SEE TRUE THE STRIATUM THE LOWER LEVELS OF D2 RECEPTORS. SHE -- HER GROUP HAS GONE TO SHOW THAT THIS ALSO HAPPENS IN INDIVIDUALS WHO ABUSE ALCOHOL AND ALSO IN OBESE INDIVIDUALS. SO APPARENTLY IT IS A PHENOMENON THAT IS OBSERVED IN OTHER INDIVIDUALS THAT STRUGGLE WITH COMPULSIVE BEHAVIORS. NOW, WE'VE KNOWN THIS FOR QUITE A WHILE NOW, AND WE I THINK THE BEGINNING IT WAS AVAILABLE, BUT THERE ARE CONSIDERABLE EVIDENCE THAT THIS IS HAPPENING. HOWEVER, THERE ARE VERY IMPORTANT QUESTIONS THAT NEED TO BE ANSWERED. ARE THEY LOWER LEVELS OF D2 RECEPTOR IN STRIATUM RISK FACTOR FOR ADDICTION OR DOES IT CREATE VULNERABLE OR ARE LOW LEVELS A CONSEQUENCE OF THE DRUG USE? SO SOME HINTS ON THIS HAVE COME FROM WORK ON NON-HUMAN PRIMATES RESEARCH BY THE GROUP OF NADER WHO SHOWED THAT ACTUALLY INDIVIDUALS WITH LOW LEVELS OF D2 RECEPTORS TENDED TO BE -- TO TAKE MORE COCAINE THAN MONKEYS THAT HAD HIGHER LEVELS OF D2 RECEPTORS POINTING OUT MAYBE THERE WAS SOME PREDISPOSITION ON THE LOWER LEVELS. AT THE SAME TIME IN THAT STUDY, BECAUSE THEY COULD COUNT ANIMALS FOR AVAILABILITY BEFORE THEY WERE EXPOSED TO THE DRUGS AND AFTER, THEY WERE ABLE TO SHOW THAT EXPOSURES TO THE STIMULANTS ALSO LOWERED THE D2 RECEPTOR LEVEL SO NOW WE'RE BEGINNING TO THINK THAT FIRST THIS ALSO HAPPENS IN PRIMATES, AT THAT POINT, AND THAT THERE MIGHT BE EVIDENCE FOR BOTH OF THESE HAPPENING SIMULTANEOUSLY. I WANT TO ALSO HIGHLIGHT THE ISSUE OR THE MAIN POINT THAT THIS IS ALSO OBSERVED IN RODENT MODELS, SO THIS IS DATA FROM RATS WHERE IT WAS FOUND THAT RATS THAT HAVE HIGH LEVELS OF D2 RECEPTORS ARE ACTUALLY THE LOW TAKERS, RATS THAT HAVE LOWER LEVELS OF D2 RECEPTORS, THEY ARE HIGH TAKER RATS, AND IMPORTANTLY IF THIS STUDY FROM 2007 THEY CORRELATED THESE LOWER LEVELS OF D2 RECEPTORS WITH ANOTHER TRAIT IMPULSIVITY ASSOCIATED ALSO WITH ADDICTION. SO, THESE DATA SUGGEST THAT THERE'S VERY STRONG CORRELATION OR SOME ASSOCIATION BETWEEN THE LEVELS OF D2 RECEPTORS AND COMPOSITE BEHAVIORS TOWARDS DRUGS OR AT LEAST DEVELOPMENT OF HIGH MOTIVATION TO TAKE THE DRUGS. HOW IS THIS HAPPENING? AND FOR SURE THESE DATA SHOWS THAT WE COULD USE RODENT MODELS TO STUDY THIS BECAUSE IT'S ALSO OBSERVED THERE. WE ALSO KNOW THAT THE CIRCUIT IS QUITE CONSERVED IN RODENTS, S SO THIS IS A SAGITTAL SECTION OF A MOUSE BRAIN SO YOU CAN SEE DOPAMINERGIC NEURONS LABELED EXPRESSING (INDISCERNIBLE) IN THIS CASE, YFD, YOU CAN SEE DENSE INNERVATION THROUGH THE WHOLE STRIATUM, AND THIS IS THE DORSAL PART, BUT THIS AREA IS THE VENTRAL PART OF THE STRIATUM, AND I'M GOING TO START HIGHLIGHTING SO WE HAVE THIS SN/VTA, STRIATUM, HIGHLIGHTING NUCLEUS CIRCUNBENCE, THE ACTIVITY IS QUITE CONSERVED. SO WE THINK THE MOUSE MODEL COULD BE ACTUALLY A REALLY GOOD ONE TO ADDRESS THIS QUESTION. MORE IMPORTANTLY, WE ALSO KNOW THAT DRUGS OF ABUSE IN THIS CASE FOR INSTANCE COCAINE, VERY IMPORTANTLY INCREASES IN DOPAMINE IN THE NUCLEUS CIRCUMBENCE. WE HAVE THE DOPAMINE TERMINALS THAT COME ON THE NUCLEUS CIRCUMBENCE, CONTAINING ALSO A DOPAMINE TRANSPORTER ENGAGED IN REUPTAKE IN DOPAMINE AS SOON AS IT IS RELEASED. AS A CONSEQUENCE OF THAT SO AS YOU MIGHT KNOW, COCAINE IS A VERY POTENT BLOCKER OF THE DOPAMINE TRANSPORTER, AND ONCE IT BLOCKS THE TRANSPORTER, INHIBITS REUPTAKE AND LIMITS DOPAMINE IN THE TERMINAL AREA. THAT'S VERY WELL UNDERSTOOD. NOW HOW IS THAT D2 RECEPTORS LEVELS CAN BE CREATED IN VULNERABILITY TO THE RESPONSE? THE COMPLICATIONS TO ANSWER THAT QUESTION, EVEN IN THE MOUSE MODEL, WAS THAT THERE ARE ACTUALLY D2 RECEPTORS IN MANY OF THESE REGIONS THROUGHOUT THE CIRCUIT. SO THERE ARE THE D2 RECEPTORS IN THE BRAIN REGION, THALAMUS, CORTEX, NUCLEUS CIRCUNBENS AND NUCLEUS. THERE'S DIVERSITY IN CELL TYPES, WE HAVE DIFFERENT AREAS AND DOPAMINE NEURONS THAT SEND THEIR PROJECTIONS TO THE NUCLEUS CIRCUNBENS, AND THERE ARE TWO MAIN POPULATIONS OF PROJECTION NEURONS, GREEN WE'RE GOING TO REFER HERE THAT FORMED THE DIRECT PATHWAY, AND THESE CELLS SEND PREDICTION BACK TO THE BRAIN AND THE OTHER HALF OF THE PROJECTION NEURONS ARE ON THE RED MSN, THAT'S SENT ACTUALLY IN THE PROJECTIONS BACK TO THE BRAIN CALLED INDIRECT PATHWAY, LATER REFERRED TO AS D AND I. AND I HAVE COLORED THEM IN THIS CARTOON RED AND GREEN PURPOSELY BECAUSE FROM WHAT WE KNOW NOW IS THESE TWO CELL TYPES NOT ONLY HAVE PARALLEL PATHWAYS, PROJECTION PATHWAYS, THEY ALSO HAVE COMPLEMENTARY EFFECTS ON THE OUTPUT OF CIRCUIT. ONE IS LIKE WHAT IS CALLED THE GOAL SIGNAL, THIS FACILITATES OUTPUT OF BASAL GANGLIA, THAT'S WHY I COLOR IT GREEN. AND INDIRECT PATHWAY OUTPUT ACTUALLY INHIBITS THE OUTPUT OF THE CIRCUITS AND TENDS TO BE KIND OF THE BREAK, AND SO I COLOR IT RED. AND I'LL GO OVER AGAIN -- I'LL COME BACK TO THESE TOPICS LATER BUT I WANT YOU TO KNOW THAT THEY ARE NOT JUST TWO DIFFERENT PARALLEL PATHWAYS BUT IN ADDITION FUNCTIONALLY HAVE COMPLEMENTARY EFFECTS. THERE ARE D2 RECEPTORS ON THESE RED MSNs THAT ARE THERE, ALSO D2 RECEPTORS IN THE DOPAMINERGIC NEURONS IN THE TERMINALS, INSTEAD OF CHOLINERGIC NEURONS THAT ARE NOT ABUNDANT BUT EXTEND PROJECTIONS THROUGHOUT THE STRIATUM, CHOLINERGIC NEURONS ALSO EXPRESS D2 RECEPTORS, AND THERE ARE D2 RECEPTORS IN MANY OF THE NEURONS THAT PROJECT TO THE STRIATUM, AND SO THERE ARE EVIDENCE THEY ARE ALSO LOCATED IN TERMINALS IN THE RELEASE. I HOPE THIS MAKES CLEAR TO YOU WHY USING PHARMACOLOGICAL TOOLS TO LOOK AT THEY EFFECTS HAS BEEN REALLY HARD TO UNDERSTAND, HOW IS THAT THE LEVELS OF D2 RECEPTORS CAN CREATE VULNERABILITY. AND IN THE LAB, WE'VE BEEN ASKING THESE VERY SPECIFIC QUESTIONS, SO WE HYPOTHESIZE EACH ONE OF THE D2 RECEPTORS HAS DIFFERENT ROLES AND ASK WHAT IS THE ROLE OF THE RECEPTORS EXPRESSED IN EACH ONE OF THESE CELLS SO THE RESPONSE TO COCAINE, WHAT ARE THE CONSEQUENCES OF REDUCING THE LEVELS OF EACH ONE OF THESE D2 RECEPTORS TO ACTIVITY OF THE CIRCUITRY BUT ALSO TO THE BEHAVIOR OF RESPONSE TO COCAINE. AND THIS QUESTIONS WE HAVE EMBARKED OVER THE PAST EIGHT YEARS HAVE BEEN REFERRED TO COCAINE WE'RE NOW MOVING ON TO DOING SIMILAR ANALYSIS ON HOW THIS AFFECTS ALCOHOL AND ALSO FEEDING BEHAVIORS, AS YOU CAN IMAGINE, HAVING THE TOOLS NOW SIMILAR STRATEGY TO THOSE OTHER SUBSTANCES AND BEHAVIORS. SO THE FIRST STORY I WOULD LIKE TO TELL YOU IS ABOUT THE ROLE OF D2 RECEPTORS EXPRESSED ON THOSE RED INDIRECT PATHWAY MSNs BECAUSE THEY ARE THE MOST ABUNDANTLY EXPRESSED IN THE STRIATUM REGION WHERE THE EVIDENCE HAS POINTED FROM DR. VOLKOR'S LAB, AND THESE RECEPTORS, WHY THEY ARE CALLED POST-SYNAPTIC RECEPTORS BECAUSE THEY ARE DOWNSTREAM OF THE -- OR POST-SYNAPTIC TO RELEASE OF DOPAMINE FROM THE DOPAMINERGIC TERMINALS, I WANT TO HIGHLIGHT WE HAVE GOOD EVIDENCE THEY ARE NOT ONLY EXPRESSED IN THE DENDRITES AND SOMA BUT ALSO EXPRESSED ON THEIR TERMINALS, WHERE THEY REGULATE NEUROTRANSMITTER RELEASE, SO SOME OF THE THINGS WE HAVE LEARNED IS THAT IN ADDITION TO THE SIGNALING SPECIFICALLY SIGNALING AND REGULATING CYCLIC AMB LEVEL, GENE EXPRESSION AND SIGNALS IN DENDRITES, THESE RECEPTORS ARE ACTUALLY LOCATED IN TERMINALS REGULATING GABA TRANSMISSION FROM THESE CELLS, MORE SPECIFICALLY THEY INHIBIT THE TRANSMISSION, THE (INDISCERNIBLE) COUPLED RECEPTORS, GIVEN SIGNALING, AND AS A CONSEQUENCE OF THESE WE'VE BEEN -- WORK FROM OUR LAB HAS SHOWN THESE RECEPTORS ARE ENGAGED IN FACILITATING LOCOMOTION AND MEDIATING LOCOMOTOR RESPONSE TO COCAINE. AND WE'RE FURTHERING NOW STUDYING HOW THIS AFFECTS COCAINE ADMINISTRATION AND REINFORCEMENT. I WANT TO BRIEFLY SHOW YOU SOME OF THE DATA. IN PART OF THIS STUDY WE ELIMINATED D2 RECEPTORS ONLY IN THESE CELLS WHILE KEEPING THE OTHER D2 RECEPTORS INTACT AND DID CONTROLS TO CHECK FOR THAT. AND WHAT THIS STUDY FIRST POINTED OUT WAS THAT THERE WAS A SEVERE STRENGTHENING OF THE -- MASSIVE STRENGTHENING OF THE GABA TRANSITION WITHIN THE STRIATUM POINTING OUT LITTLE BRANCHING COLLATERALS OF THESE IMSNs THAT UNTIL THEN HAD BEEN KIND OF NEGLECTED AND FORGOTTEN, AND STUDYING TRANSGENIC MICE PERFORMED CONDITIONAL KNOCKOUT MICE COLLATERAL TRANSMISSION COULD INHIBIT, THERE'S (INDISCERNIBLE) IN THE VENTRAL PALLIDUM SO THE BREAKS ARE STRONG IN THIS CASE. AS A CONSEQUENCE OF THE MICE THAT SHOW MOUSE -- THE LACTOSE D2 RECEPTOR SHOW MOTOR IMPAIRMENTS, BRADY KINESIA, WHEN THEY MOVE THEY MOVE SLOWER, BUT THEY ALSO THEN TRAVEL -- THE DISTANCE TRAVELED IS SLOWER, AND THEY SHOW HIGHER PERCENT OF IMMOBILITY, SUGGESTIVE OF IMPAIRMENTS AND INITIATING MOVEMENT AS WELL THAT WE OBSERVE TOGETHER WITH OTHER DATA. SO THESE EFFECTS WERE DEPENDING ON GENE DOSAGE TO BASICALLY HOW MUCH THE D2 RECEPTORS WERE REDUCED IN THE FULL KNOCKOUT, THE REDUCTION IS APPROXIMATELY 85% FOR MESSENGER IN THE STRIATUM AND HETEROZYGOTES, THIS IS 40% REDUCTION. SO IN GENE DOSAGE DEPENDENT THESE GENES REGULATED THE LOCOMOTION, BASELINE LOCOMOTION OF THESE ANIMALS, THIS WAS RECENTLY PUBLISHED IN NEURON, AND WE THINK IT PROVIDES REALLY GOOD EVIDENCE BECAUSE -- PROVIDES REALLY GOOD EVIDENCE OF HOW A PARKINSONIAN-LIKE PHENOTYPE MEDIATED BY LACK OF DOPAMINE OR DEPLETION OF DOPAMINE IS ACTUALLY MEDIATED BY THE REDUCED ACTIVATION OF ONE OF THEIR OWN RECEPTORS, D2 RECEPTORS ON THESE CELLS. SO JULIA LEMOS WHO IS HERE RAN EXPERIMENTS WHERE SHE RESCUED LOCOMOTORRIVEY, IF YOU MOTIVATE RECEPTORS SELECTIVELY, YOU CAN INCREASE DISTANCE TRAVEL AND INCREASE ALSO I THINK SPEED, NOT SHOWN HERE, BUT YOU CAN INCREASE SUSTAINED LOCOMOTION AND THE SAME EFFECT WAS SEEN BY PARTIAL RESCUE OF THESE GI SIGNALING IN BOTH THE VENTRAL STRIATUM, NUCLEUS ACCUMBENS OR DORSAL STRIATUM. IN THIS CASE THE DELETION WAS COMPLETE AND WE CAN RESCUE IT PARTIALLY BY RESTORING THE SIGNALING IN EACH ONE OF THE TWO REGIONS. SO FURTHERMORE, WE SHOWED THAT THESE ANIMALS THAT LACK D2 RECEPTORS HAVE IMPAIRED COCAINE INDUCED LOCOMOTION. SO ACUTE -- THIS IS THE TRACES OF THE ACTIVITY OF ANIMALS THAT RECEIVE COCAINE, AND CONTROL ANIMALS ACTUALLY INCREASE LARGELY THEIR LOCOMOTION AND RUN IN THE OPEN FIELD A LOT. BUT KNOCKOUT MICE SHOW NO RESPONSE TO ACUTE COCAINE ADMINISTRATION AND THE HETEROZYGOTES ON INTERMEDIATE PHENOTYPES. SO IT TOOK THESE ANIMALS THAT DON'T HAVE D2 RECEPTORS AND IMSN A HIGH DOSAGE OF COCAINE TO SHOW LOCOMOTOR RERESPONSE. WE DID VOLT OHMETY, YOU CAN RELEASE IN CONTROLS AND KNOCKOUT ANIMALS, AND THEN COCAINE ACUTELY ACTUALLY HAS A VERY SIMILAR EFFECT IN ENHANCING THIS TRANSIENT SO THE DEFICIENCIES REALLY DOWNSTREAM -- SORRY -- OF D2 -- OF DOPAMINE RELEASE, AND I WILL SHOW YOU THEN THE CONTROL FOR THAT. BUT WE ALSO FOUND THAT IN THESE ANIMALS WHILE THE ACUTE LOCOMOTOR RESPONSE OF COCAINE ON THE FIRST DAY WAS TOTALLY IMPAIRED, AS YOU GIVE REPETITIVE COCAINE INJECTIONS THE ANIMAL DEVELOPS LOCOMOTION AND SO BY THEIR CHALLENGE DAY THE ANIMALS NOW SHOW A PRONOUNCED LOCOMOTOR RESPONSE, AND HETEROZYGOTES MICE YOU CAN SEE HOW THIS RESPONSE IS CLEARLY INCREASING AND BY CHALLENGE DAY THEY LOOK LIKE CONTROL ANIMALS. THIS PHENOMENON OF INCREASED LOCO MOTOR EFFECT (INDISCERNIBLE) AND WE WERE SURPRISED TO FIND WHILE THE ACUTE RESPONSE WAS TOTALLY IMPAIRED, THE SENSITIZED RESPONSE WAS INTACT AND ALSO JUST RUNNING. INITIALLY -- THIS MAKES A LOT OF SENSE WITH THE OTHER -- THE REST OF THE LITERATURE THAT SUGGESTS THAT THE ACUTE EFFECTS OF COCAINE AND THE SENSITIZED RESPONSE ARE ACTUALLY MEDIATED BY DIFFERENT PROCESSES. SO D1 RECEPTORS ALSO EXPRESSING THE STRIATUM TEAM TO BE IMPORTANT MEDIATING SENSITIZATION WHICH IS KIND OF A LEARNED PART OF THAT, AND THE ANIMAL LEARNED, IT'S A WAY OF MEASURING ASSOCIATION BETWEEN THE DRUG AND THE ENVIRONMENT. AND THAT EFFECT IS INTACT IN THIS KNOCKOUT SO WE THINK THE TARGETED DELETION OF D2 RECEPTORS IS CLEARLY IMPAIRING A VERY SPECIFIC PART OF THE COCAINE RESPONSE, BUT NOT ALL OF IT, OF COURSE. AND LAUREN WENT ON TO FURTHER DEMONSTRATE THESE ON THE ACUTE RESPONSE BY NOW USING ALSO GI DREADS THAT SHE EXPRESSED ON IMSNs IN THE KNOCKOUT BACKGROUND, AND SHOWED THAT IN THE KNOCKOUT ANIMALS WHERE THEY DON'T HAVE THE D2 RECEPTORS WE CAN RESTORE THE INHIBITION OF THE GABA TRANSMISSION, THESE ARE GABA -- GABA POST-SYNAPTIC RESPONSES, BOTH BY ACTIVATING THE CELLS, NOW ACTIVATION OF GI COUPLED DREAD CAN DO WHAT DOPAMINE DOES IN THESE CELLS THROUGH THE TWO RECEPTORS, TO INHIBIT THAT GABA TRANSMISSION. SO AS A CONTROL THAT WE CAN GET GI COUPLE ACTIVATION AND EFFECTS THAT MIMIC, THAT DOPAMINE WILL BE DOING ON THE CELLS, AND WHEN WE DO THAT WE CAN NOW SEE THAT KNOCKOUT ANIMALS THAT OTHERWISE MOVE VERY LITTLE, WHEN WE GIVE THEM CNO, THOSE KNOCKOUT ANIMALS THAT HAVE THE GI DRDs BUT NOT THE CONTROLS ENHANCE THEIR LOCOMOTION, FURTHER POTENTIATED BY PRESENCE OF COCAINE. I'M GOING TO TRY TO SUMMARIZE THIS HERE. IN THIS CARTOON. SO WHAT WE FOUND IS THAT IF WE REMOVE D2 RECEPTORS, THE GABA TRANSMISSION, THE BREAK THE CELLS EXERT ON THE OUTPUT ARE REALLY STRONG AND DATA SUGGESTS THERE'S A SIGNIFICANT AMOUNT OF BREAK ALREADY IN THE SYSTEM, SUCH AS -- AND THE BREAK COMES FROM THE INDIRECT PATHWAY DOWNSTREAM PROJECTIONS TO THE VENTRAL PALLIDUM AND SO ON BUT ALSO I TOTALLY LOCALLY THROUGH THE COLLATERALS WE'VE NICELY SHOWN IN THE PAPERS, AND WE THINK THAT WE HAVE GOOD EVIDENCE D2 RECEPTORS, ACTIVATION IN THOSE TERMINALS, INHIBITS THIS BREAK, SUPPRESSES THE FOOD OF THE BREAK AND BY DOING THAT ENHANCES -- INHIBITS DIRECT PATHWAY AND ENHANCES GOAL PATHWAY, SO BASICALLY A MECHANISM BY WHICH DOPAMINE ACTING ON THESE RECEPTORS CAN ENABLE ACTIVATION OF THE GO PATHWAY THAT I SHOULD MENTION AT THIS POINT GETS DIRECTLY ACTIVATED BY DOPAMINE THROUGH D1 RECEPTORS. DOPAMINE DOUBLE ON D1 AND DID2 RECEPTORS ENHANCES THE OUTPUT OF THE GO PATHWAY AND DOES IT DIRECTLY WITH THE D1 RECEPTORS ON THE GREEN CELLS, BUT IT DOES IT ALSO INDIRECTLY BY REMOVING THE BREAK THE INDIRECT PATHWAY IS HAVING ON THOSE CELLS. SO AS I SAID, WE HAVEN'T ANSWER ALL THE QUESTIONS HERE. THERE ARE NOW MORE THINGS THAT WE ARE LOOKING, WE'RE LOOKING AT HOW THIS ANIMAL (INDISCERNIBLE) COCAINE AND ONE PREDICTION, BASED ON THE WORK IN HUMANS WITH THE PET SCANNING WILL BE THESE ANIMALS WILL ACTUALLY HAVE HIGH MOTIVATION TO TAKE THE DRUG AND SO ON, WE'RE ABOUT TO FIND THAT OUT. MORE IMPORTANTLY WHAT WE ALSO FOUND AND WHAT WE'RE STUDYING, AND I WON'T BE ABLE TO TELL YOU HERE, IS THAT REMOVAL OF THESE RECEPTORS IN THIS POPULATION OF NEURONS GENERATES A CASCADE OF CONFUSEATORY MECHANISMS THROUGHOUT THE CIRCUITS, SUCH AS DID1 CELLS, DIRECT PATHWAY CHANGE DRAMATICALLY IN INPUT. I DIDN'T WANT TO TALK ABOUT THAT BECAUSE IT'S THINGS STILL ONGOING AND WE'RE NOT SURE, WE DON'T HAVE ALL THE PIECES. BUT IT'S PROVIDING US SIGNIFICANT EVIDENCE THE WHOLE CIRCUITRY CHANGES AS A CONSEQUENCE OF THOSE D2 RECEPTORS AND WE SPECULATE THAT IT MIGHT BE TRIGGERED NOT JUST BY DECREASING LEVELS BUT COMPENSATORY MECHANISMS THAT COME TO COMPENSATE, TO PREVENT THAT. SO THAT'S ONE THING. THE OTHER THING IS THAT D2 RECEPTORS IN OTHER PARTS OF THE CIRCUIT THAT COULD BE PLAYING A ROLE, AND THAT WE HAVE, AND OTHERS, TOTALLY UNDERESTIMATED BECAUSE THEY TEND TO BE LESS ABUNDANT, RELATIVELY TO THE ONES IN IMSNs. HERE IS ONE IMPORTANT EXAMPLE BY WHICH WE PUBLISHED, STUDYING SEVERAL YEARS ROLE OF D2 EXPRESSERS EXPRESSED ON DOPAMINERGIC NEURONS, THE SAME THAT RELEASE DOPAMINE, THEY ALSO HAVE D2 RECEPTORS. ONE HYPOTHESIS HERE THESE ARE CALLED AUTORECEPTORS, ARE THEY INVOLVED IN FEEDBACK INHIBITION, THEY ARE KIND OF TELLING DOPAMINE NEURONS YOU HAVE RELEASED ENOUGH, YOU NEED TO STOP. THEY ARE ACTUALLY EVIDENCE THEY ARE DOING PRETTY MUCH THAT, IN PART FROM OUR WORK, BUT ALSO OTHERS, THAT THESE RECEPTORS IS DECREASING SYNTHESIS AND RELEASE OF DOPAMINE, VERY GOOD EVIDENCE OF THAT. AND AS A CONSEQUENCE OF THAT, ACTIVATION OF THESE RECEPTORS CAN REDUCE BASAL LOCOMOTION, CAN ALSO PUT KIND OF THE LIMIT TO THE COCAINE-INDUCED LOCOMOTION, IT'S RESTRAINING THE EXTENT OF THE STIMULANT EFFECT, AND IT'S ALSO PUTTING SOME BREAK TO OTHER BEHAVIORAL RESPONSES TO COCAINE, SUCH AS THE REWARDING PROPERTIES AND REINFORCING PROPERTIES. AND I'M GOING TO SHOW YOU EVIDENCE OF THAT FROM OUR STUDIES WHEN WE USED CONDITIONAL KNOCKOUT MICE AND CITED DELETED IN CELL-SPECIFIC MANNER DELETED D2 RECEPTORS JUST FROM THESE CELLS. WE FOUND MICE LACKING D2 AUTORECEPTORS SHOW HYPER LOCOMOTOR PHENOTYPE SO THEY MOVE A LOT MORE. AND IN PART THAT IS BECAUSE IN VIVO THESE ANIMALS RELEASE MORE DOPAMINE. BUT FURTHERMORE, WE SHOW THAT EVEN IN THE SLICE IN VITRO WHERE WE CAN TITRATE THE AMOUNT OF DOPAMINE THE ANIMAL -- THE FIBROUS RELEASE, WE MEASURE THESE WITH FAST VOLT OMETRY, INVOKE DOSIMETRY IN BACK, CONTROL FOR MICE LACKING AUTORECEPTORS AND WE FOUND THAT THAT APPLICATION OF COCAINE LED TO A MUCH LARGER TRANSIENT IN THOSE MICE THAT LACK THE AUTORECEPTORS. EVEN IN VITRO RESPONSE TO COCAINE IS ENHANCED IN THESE ANIMALS AND WE FIGURED OUT EXACT MECHANISM AND ACTUALLY POINT TO SOME VERY (INDISCERNIBLE) ROLE OF THESE TERMINALS. OUR DATA PROVIDES EVIDENCE THAT THE DOPAMINE TERMINALS RELEASE DOPAMINE AND THIS TRANSPORTER LOCATED ON TERMINALS IS CRITICAL IN REDUCING THE CONCENTRATION OF DOPAMINE AND ACTUALLY PREVENTING IT FROM ENGAGING THE AUTORECEPTORS, BECAUSE IT KEEPS CONCENTRATION LOW CLOSE TO THAT, TO RECEPTOR. NOW IN THE PRESENCE OF COCAINE, THAT THE TRANSPORTERS ARE BLOCKED, DOPAMINE STARTS TO INCREASE, ENGAGES THEN THE AUTORECEPTORS THAT INHIBIT DOPAMINE RELEASE, AND THEN THAT LOWERS DOPAMINE RELEASE. SO EVEN THOUGH IN NORMAL CONDITIONS DOPAMINE TRANSIENTS ARE PROLONGED AND THERE'S MORE CONCENTRATION OF DOPAMINE EXPRESSED, WE HAVE PRETTY GOOD EVIDENCE RELEASE ITSELF IS DECREASED. AND I'LL SHOW YOU SOME OF THAT BUT THERE'S MORE. IN THE D2 KNOCKOUTS THAT DON'T HAVE THESE RECEPTORS, NOW, THAT RELEASE -- THE INHIBITION OF DOPAMINE RELEASE CANNOT HAPPEN, WHEN YOU PUT COCAINE YOU GET JUST A BLOCK OF TRANSPORTER AND CONCENTRATION IS MUCH HIGHER. ONE PIECE OF EVIDENCE NICELY SUPPORTS THAT HYPOTHESIS I TOLD YOU IS THAT IF NOW IN CONTROL ANIMALS WE DO THE SAME EXPERIMENT BUT IN THE PRESENCE OF THE D2 RECEPTOR ANTAGONIST, WHEN WE HAVE THESE RECEPTORS BLOCKED, WE SEE THAT NOW COCAINE HAS A VERY SIMILAR EFFECT THAN IN THE KNOCKOUT. SO THERE'S A MASSIVE INCREASE IN THE DOPAMINE TRANSIENT THAT IS NOT JUST AT A TIME THAT THE TRANSIENT, CONCENTRATION TRANSIENCE LASTS LONGER, BUT ALSO THE AMOUNT IS MUCH LARGER. THIS WAS SEEN IN VITRO. WE ALSO SAW MICE LACKING D2 AUTORECEPTORS SHOW ENHANCED LOCOMOTOR RESPONSE, SO A LOW DOSE OF COCAINE THAT HAD NO MINIMAL EFFECT ON LOCOMOTION ON WILDTYPE ANIMALS IS ALREADY SUFFICIENT TO ENHANCE LOCOMOTION IN THESE MICE LACKING THE AUTORECEPTOR, AND THEN WE WENT ON TO DO A MUCH MORE LONGER INTERESTING STUDY IN WHICH WE LOOK HOW NOW THESE ANIMALS TAKE COCAINE IN A SELF ADMINISTRATION PARADIGM. SO WE IMPLANTED ANIMALS WITH (INDISCERNIBLE) THAT GOES INTO THE JUGULAR VAIN IN THE INTRAJUGULAR CATHETER AND WE CAN THEN PUT A PORT ON THEIR BACK AND CONNECT IT TO (INDISCERNIBLE) THAT CAN DELIVER COCAINE INTRAVENOUSLY WHEN THE ANIMAL POKES THEIR NOSE IN A HOLE OR PRESS A LEVER. AND WHEN WE DID THAT, WE FOUND THAT ANIMALS THAT LACK D2 RECEPTORS LEARN FASTER AND HIGHLY PERCENTAGE OF THEM ENGAGE JUST IN COCAINE SELF-ADMINISTRATION COMPARED TO THEIR CONTROL LITTER MATES. THIS IS A DATA SHOWING HOW MANY SESSIONS IT TAKES THE ANIMALS TO REACH THE CRITERIA FOR ACQUISITION, AND AS YOU CAN SEE THE D2 KNOCKOUT ANIMALS ARE REALLY FAST, WITHIN JUST A FEW SESSIONS THEY REALLY GET IT. WHILE THERE ARE IS A WIDESPREADING WILDTYPE ANIMALS, SOME ANIMALS GET IT REALLY FAST TOO, BUT THEN THERE ARE THE SLUGGISH ONES THAT NEVER GET IT, LIKE HERE. THEY WILL NEVER ENGAGE IN COCAINE SELF-ADMINISTRATION. SO THAT THAT IS PRETTY (INDISCERNIBLE). WE WENT INDEED FURTHER CONTROLS LOOK HOW THESE ANIMALS TAKE SUCROSE REWARD, NO CONTROLS IN TWO KNOCKOUTS. THEY ALL ENGAGE AND ALL LEARN AT SIMILAR SPEEDS SUCROSE SELF-ADMINISTRATION SO NOW IF WE COMPARE SUCROSE AND COCAINE SELF-ADMINISTRATION THIS IS WHAT HAPPENS IN LITTERMATE CONTROL MICE. THEY WILL ALL LEARN AND QUITE QUICKLY TO TAKE -- TO PRESS LEVERS FOR SUCROSE REWARDS, THEY WILL LEARN SLOWER AND NOT ALL OF THEM WILL LEARN TO TAKE COCAINE. BUT IN MICE WITH THAT LACK D2 RECEPTORS, THIS WAS VERY SHOCKING FOR US TO FIND THAT ACTUALLY THEY LEARN EQUALLY, OR IF YOU HAD TO FIND A DIFFERENCE, THEY EVEN LEARN MORE BETTER TO TAKE COCAINE THAN TO TAKE SUCROSE REWARD. SO THESE DATA ALREADY POINTS TO AN IMPORTANT ROLE OF THESE AUTORECEPTORS IN REGULATING COCAINE TAKING BEHAVIOR AND MORE SPECIFICALLY COCAINE IN THIS CASE. I WAS GOING TO SAY BUT NOT NECESSARILY SUCROSE, AT LEAST UNDER THESE CONDITIONS. THE OTHER SURPRISING FINDING FROM THIS STUDY CAME WHEN WE ACTUALLY STOPPED THE ANIMALS FROM TAKING COCAINE. NOW I WAS GOING TO ANIMATE THIS AND I FORGOT. SO DON'T PAY ATTENTION TO THESE FIRST. LET'S LOOK HERE. WE LET THE ANIMALS ACTUALLY SELF-ADMINISTER COCAINE FOR 15 SESSIONS. AND THEN THIS IS AN EXAMPLE OF A CONTROL MICE, AND YOU CAN SEE HOW COMPARED TO THE MICE LACKING AUTORECEPTORS, THEY ACTUALLY TAKE LONGER TO LEARN A STABLE RESPONDING, WHILE KNOCKOUT ANIMALS ACTUALLY LEARN IT SUPER FAST. BUT FOR THE MOST PART THERE WAS NO OTHER SIGNIFICANT DIFFERENCE ON THEIR LEVELS OF TAKING AT THIS POINT. BUT THE OTHER SURPRISING THING THAT HAPPENED WAS WHEN WE THEN CONTINUED THE ANIMALS ON (INDISCERNIBLE) SESSIONS THEY DON'T GET COCAINE ANYMORE, JUST SALINE, SO NO REWARD. THEY BEGINNING THEY SHOW (INDISCERNIBLE) AND PRESS EVEN MORE, LIKE WHERE IS MY COCAINE, BUT VERY SOON LEARN THEY ARE NOT GOING TO GET COCAINE ANYMORE AND STOP RESPONDING FOR THE MOST PART. AT LEAST COMPARED TO WHAT HAPPENS IN THE OTHER TWO KNOCKOUTS. THESE ANIMALS, AND I'M JUST SHOWING YOU AN EXAMPLE, BUT IN THE PAPER, OF COURSE IT'S ALL THE SUMMARIZED DATA. THESE ANIMALS SHOW A LOT MORE PERSEVERANCE RESPONDING FOR COCAINE, THEY HAVE LEARNED TO GO FURTHER TO SHOW, THEY CONTINUE TO PRESS AND GO FURTHER TO SHOW THIS IS DRIVEN BY THE CUES THAT WERE ASSOCIATED WITH THE DRUG. IF WE MINIMIZE AND TAKE THE CUES AWAY, THESE ANIMALS CAN ACTUALLY STOP RESPONDING. SO WE THINK THESE -- WE THINK THESE STUDIES TOGETHER ACTUALLY THERE ARE THREE STUDIES THERE PROVIDE REALLY GOOD EVIDENCE THAT THE D2 AUTORECEPTORS, THOSE EXPRESSED ON THE SAME DOPAMINERGIC NEURONS, CAN BE PLAYING AN IMPORTANT ROLE AS WELL EVEN THOUGH THEY ARE NOT THE MOST ABANDONED AND CAN CONTRIBUTE TO VULNERABILITY. SO IN SUMMARY, I'D LIKE TO SAY THAT I'LL SHOW YOU EVIDENCE TODAY THAT D2 RECEPTORS PLACE DIFFERENT FUNCTIONAL ROLES IN EACH -- ON THE BEHAVIORAL RESPONSE IMPERIAL BUT ALSO RESPONSE TO COCAINE DEPENDING WHICH NEURONAL TYPE THEY WERE EXPRESSED. THEY HAVE DIFFERENT ROLES. AND WE THINK THAT -- SO MAYBE I SHOULD GO OVER BRIEFLY, SO D2 RECEPTORS ON THE INDIRECT PATHWAY, THE RED CELLS, ARE REALLY IMPORTANT IN REMOVING THE BREAK THAT THESE CELLS ARE EXERTING ON THE WHOLE CIRCUIT. D2 RECEPTORS IN THE DOPAMINE NEURONS, THOSE AUTORECEPTORS, ARE SOMEHOW KIND OF A BREAK ON DOPAMINE ITSELF. SO THESE HAVE KIND OF OPPOSITE FUNCTIONS, BUT WE ALSO THINK OUR WORK HAS SHOWN EVIDENCE THAT BOTH OF THESE RECEPTORS, WHILE THEY PLAY UNIQUE AND SOMETIMES CONTRIBUTING TO VULNERABILITY TO ADDICTION, IN WAYS IN WHICH WE'RE STARTING TO UNDERSTAND AND ASSOCIATE BUT WILL PROBABLY TAKE A COUPLE MORE YEARS TO HAVE A COMPLETE PICTURE. SO WITH THAT SAID, NOW I WANT TO REALLY END BY THANKING THE PEOPLE FROM THE LAB, THE CURRENT LAB MEMBERS. BUT ALSO ALL OUR PAST MEMBERS, INCLUDING HERE I CAN SEE PAUL KRAMER, THANK YOU FOR COMING AND SHOWING SUPPORT. PAUL, WHERE ARE YOU? PAUL KRAMER WAS A POST-BAC IN THE LAB, A WHILE AGO, THEN HE WENT TO GRADUATE SCHOOL, OREGON. OHSU, AND NOW HE'S BACK AT POSTDOC HERE IN NINDS SO WE'RE VERY HAPPY TO HAVE PEOPLE, GOOD PEOPLE, RECYCLE BACK TO NIH. BUT A LOT OF THE, YOU KNOW, EVERYBODY HAS CONTRIBUTED IMMENSELY TO THE WORK ON THE LAB, BUT WHAT I WANTED TO HIGHLIGHT IS THE PEOPLE INVOLVED IN THE WORK, I'LL SHOW YOU TODAY, I'LL SHOW YOU VOLTOMETRY IN THE LAB AND WORK ON JULIA ON THE ROLE OF D2 RECEPTORS IN NEURONS AND ALSO JULIA AND LAUREN WORKED TOGETHER WITH AYA TO UNDERSTAND THE ROLE OF THE D2 RECEPTORS AND IMSNs IN MEDIATING RESPONSE TO COCAINE AND INHIBITION OF GABA œI ALSO TOLD YOU ABOUT THE WORK, ALANA KAPLAN HAD DONE IN THE LAB CHARACTERIZING KNOCKOUT ANIMALS, SELF-ADMINISTRATION STUDY, I SHOWED YOU WORK BY KATIE AND ROLAND IN THE LAB AS WELL. AND FINALLY, I ALSO WANT TO THANK OUR COLLABORATORS, SPECIFICALLY MARCELLO WHO GENERATED CONDITIONAL KNOCKOUT MICE THAT WERE USED IN THE LAB, ACTUALLY THE FLOCKED MICE THAT HAD BEEN USED FOR ALL THESE STUDIES, AND OUR COLLABORATORS DAVID SO WORK EARLY ON BY BELLA WAS DONE IN COLLABORATION WITH THESE TWO INVESTIGATORS. LOTS OF COLLABORATORS AT NIH, INCLUDING LES THAT WAS INVOLVED IN THE STUDY OF D2 RECEPTORS AND HOW THEY IMPAIR MOVEMENT ON PARKINSONIAN LIKE PHENOTYPES AND FINALLY I WANT TO ACKNOWLEDGE OF COURSE THE FUNDING FROM NIAAA THAT HAS BEEN MY HOME AND THE PEOPLE -- THE INSTITUTION PROVIDING ALL THE FINANCIAL BUT ALSO EMOTIONAL SUPPORT, AS WELL AS OF COURSE NINDS WHO HAS CONTRIBUTING SIGNIFICANTLY TO FUNDING OF MY LAB OVER THE PAST EIGHT YEARS. THANK YOU. [APPLAUSE] >> QUESTIONS? DAVID? >> THAT WAS AN ELEGANT TALK, VERONICA. I WANTED TO ASK YOU ABOUT THE UNIFYING CONCEPT OF COMPULSIVE BEHAVIOR, WHERE I ASSUME THAT YOU'RE HOPING THAT YOU CAN CLOSE IN ON SOME COMMON CIRCUITRIES OF COMPULSIVE BEHAVIOR. HOW MUCH OF COMPULSIVE BEHAVIOR DO YOU THINK IS IN THIS VTA TO STRIATAL CIRCUITRY AND HOW MUCH LIES ELSEWHERE? FOR EXAMPLE, PATIENTS WHO ACTUALLY HAVE OCD ARE NOT AT BASELINE, HIGH NOVELTY RESPONSIVE, AND, YOU KNOW, HIGH MOVEMENT AND THEY ARE NOT REALLY LEARNING THEIR COMPULSIVE BEHAVIOR AS THE ADDICTED ANIMALS OR PATIENTS ARE. >> OH, SO THE QUESTION IS -- >> THE QUESTION IS, IS COMPULSIVE BEHAVIOR MORE OF A COMMON BEHAVIORAL EXPRESSION, OR HOW MUCH OF IT OR WHAT PART OF IT IS IS ARISING FROM THIS CIRCUITRY? DO YOU THINK THIS IS THE ADDICTION COMPULSIVE BEHAVIOR OR DO YOU THINK THIS IS MORE GENERAL? >> OH, OKAY. SO I WANT TO -- I DON'T THINK I HAVE ALL THE ANSWERS TO THOSE QUESTIONS. >> IT WAS ASKED IN SUCH AN IMPOSSIBLE WAY. >> YES. NO, YOU ABOUT I THINK I'M GOING TO PROBABLY TRY TO ANSWER IT. WHEN I THINK -- WE HAVE SPENT THE MOST TIME THINKING ABOUT COMPOSITE BEHAVIORS TOWARDS DRUGS OF ABUSE. AND EVEN THEN, YOU WANT TO THINK, OH, YOU CAN ONLY SEE THEM EXPRESSED IN THE CONTEXT OF THE DRUG OR ONCE THE ANIMALS HAVE TAKEN THE DRUG SO YOU COULD THINK, OH, THESE, THE DRUG ITSELF, IS GENERATING THE COMPOSITE BEHAVIORS. HOWEVER, THIS IS A POSSIBILITY. HOWEVER, IT'S ALSO POSSIBLE THAT THESE INDIVIDUALS ALREADY THEIR CIRCUITRY SHOWS DIFFERENCES IN WHICH THEY HAVE PROPENSITY TO GENERATE OR TO TRIGGER THOSE BEHAVIORS TOWARDS DRUGS, IF THEY ARE THERE, BUT ALSO POSSIBLY THROUGH OTHER TRIGGERS, AND THERE'S EVIDENCE THAT WITH ASSOCIATIONS OF ADDICTION AND IMPOSIVITY AND OTHER TRAITS AS IF THEY ARE INDIVIDUALS THAT ALREADY HAVE DIFFERENT CIRCUITRY THAT THEN MAKES THEM VULNERABLE TO DEVELOP ADDICTION, YOU ABOUT THEY COULD MAKE THEM VULNERABLE TO DEVELOP ALSO OTHER COMPULSIVE BEHAVIORS. THAT SAID, I AGREE THAT THERE ARE PROBABLY DIFFERENT ALTERATIONS THAT HAPPEN IN INDIVIDUALS THAT ARE -- DEVELOPING ADDICTION AND OCD PATIENTS, SO THERE'S NOT GOING TO BE THE SAME CHANGES WE SPECULATE, BUT THAT THE CHANGES ARE GOING TO BE CARRIED IN THE SAME CIRCUITRY, YES. THAT IS AT LEAST ONE OF OUR PREMISE OF OUR STUDIES, AND THAT'S WHY WE'RE FOCUSING ON CIRCUITRY. DOES THAT ANSWER? >> YES, BEAUTIFUL ANSWER. NOBODY IS UP HERE YET SO ONE MORE, WHICH IS THAT THE CHANGES IN D2 EXPRESSION THAT VOLKOW AND OTHERS HAVE SHOWN ARE REALLY INTERESTING. ARE THOSE CHANGES INDUCED IN D2 EXPRESSION, ARE THEY ACROSS THESE DIFFERENT TYPES OF CELLS, OR ARE THEY IN ONE TYPE OF CELL OR ONE REGION OR ANOTHER? >> YEAH, NO, THAT'S A GREAT QUESTION. WE DON'T KNOW, BECAUSE THERE WE SHOULD -- AND WE ALSO CANNOT EVEN TALK ABOUT LEVELS OF WHAT WE JUST CAN TALK ABOUT AVAILABILITY, SO BASICALLY BINDING TO LEVEL LIGAND, SO WHEN THERE'S LESS OF THAT BINDING WE CAN SAY THAT THEY ARE BINDING LESS SO LESS RECEPTORS AVAILABLE TO BINDING, MIGHT BE BECAUSE THEY ARE HIDDEN INSIDE THE CELL AND UNAVAILABLE, THEY ARE NOT EVEN THERE, OR THEY ARE OCCUPIED BY DOPAMINE, SO THAT'S ALSO -- BUT WE DON'T REALLY KNOW EVEN WHICH POPULATION. AND THAT'S WHY WE'VE BEEN USING THESE MICE WITH THE PREMISE MAYBE THEY ARE SELECTIVE REDUCTION, SELECTIVE RECEPTORS AND ONE SUBTYPE COULD GENERATE THE VULNERABILITY AND NOT OTHERS. YES? >> COULD YOU GO TO THE MICROPHONE BECAUSE WE ARE TRANSMITTING. >> YOUR FINAL SLIDE, I MEAN THE ONE BEFORE THE ONE THAT'S UP NOW, YOU -- THIS SLIDE SEEMS TO IMPLY AT LEAST TO MY VIEWING, THAT YOU'RE KNOCKING OUT THE D2 RECEPTOR IN THE DOPAMINERGIC NEURONS OF THE TEGMENTAL AND (INDISCERNIBLE) AND YET THE FUNCTIONAL SIGNIFICANCE IS RESTRICTED TO THE NUCLEUS ACCUMBENS AND SOMEHOW IS NOT RELEVANT TO THE PROJECTIONS TO THE DORSAL STRIATUM. DID I IMPERFECTLY INTERPRET THAT? >> YEAH, I THINK IT'S SOMETHING WE'RE STILL TRYING TO UNDERSTAND BUT THE DECEMBER IN THE DOPAMINERGIC THAT PRESENT TO THE DORSAL, AND WE KNOW EVEN THIS DRIVE BEHAVIOR SUCH AS COCAINE-INDUCED BEHAVIORS, THEY ARE MAINLY INITIALLY INITIATED BY THE NUCLEUS ACCUMBENS AND VENTRAL PART OF THE STRIATUM BUT EVIDENCE AFTER CHRONIC TREATMENT OR EXPOSURE ENGAGEMENT OF THE PART OF THE STRIATUM AS WELL EVEN FOR DRUGS USED, VERY BIASED FOR VENTRAL, BUT THERE ARE OTHER BEHAVIORS, SO SUCH AS THE INCREASED -- THE HYPERACTIVITY THAT I SHOWED YOU THESE MICE SHOW, THAT COULD BE OF COURSE MEDIATED IN LARGE PART FOR THE CHANGES IN THE DORSAL STRIATUM. >> WITH RESPECT TO THE BEHAVIORS AND IMPLICATIONS FOR COMPULSIVE BEHAVIOR, YOU ARE AGNOSTIC ABOUT THE ROLE OF THE DORSAL STRIATUM, IT COULD BE AS EFFECTIVE A DRIVER FOR THOSE BEHAVIORS AS IS THE NUCLEUS ACCUMBENS? >> SURE, AND WE ACTUALLY KNOW . >> NOT THAT I'M PUSH POLLING HERE. >> NO, NO, NO. I THINK IT'S A GOOD KIND OF CLARIFICATION. ESPECIALLY WHEN WE TALK ABOUT OTHER MOTOR OUTPUTS SUCH AS GROOMING, FOR INSTANCE AND SEE FOR INSTANCE MICE WILL ENGAGE IN COMPULSIVE GROOMING. THERE'S EVIDENCE THAT ALSO YOU CAN SPECULATE THAT THE DORSAL STRIATUM IS PLAYING A MUCH MORE IMPORTANT ROLE IN THOSE TYPE OF COMPULSIVE BEHAVIORS AND THERE'S EVIDENCE IN LITERATURE THAT EXCESSIVE GROOMING COULD BE INVOLVED BY ACTIVATION OF CORTICAL INPUT TO THE DORSAL STRIATUM. >> SIMILAR TO THE PREVIOUS QUESTION, COULD YOU SPECULATE ON THE DIFFERENCE OR IF THERE IS A DIFFERENCE BETWEEN THE D2 RECEPTORS ON THE EXON TERMINALS AND THOSE IN THE MID-BRAIN? >> WELL, YEAH. THAT'S A GREAT QUESTION. WE CAN SPECULATE THAT THERE MIGHT BE EVEN A DIFFERENCE BETWEEN D2 RECEPTORS WITHIN THE SAME CELL, THOSE THAT ARE EXPRESSED IN THE TERMINALS AND THE DENDRITES AND SOMA, THEY COULD BE SIGNALING THROUGH DIFFERENT LIKE MORE GI OR RESTING, SO THAT'S I THINK MORE STUDIES NEEDS TO BE DONE, BUT YOU CAN SEE ALREADY TRENDS ON LIKE PEOPLE ARE MUTATING D2 RECEPTORS TO MAKE THEM MORE ARRESTING, BIAS FOR ARRESTING OR GI COUPLE SIGNALING AND YOU CAN SEE DIFFERENTIAL IMPAIRMENTS ON RESPONSES OF D2 IN THE SOMA OR THE DENDRITES, SO MORE WOULD HAVE TO BE DONE THERE BUT IT'S LIKELY EVEN WITHIN THE SAME CELL RECEPTORS LOCALIZE TO DIFFERENT COMPARTMENTS ARE ENGAGING IN DIFFERENT SIGNALING, AND THEY ARE AFFECTING DIFFERENT FUNCTIONS SUCH AS IN ONE CASE GENE EXPRESSION, BUT IN ANOTHER GABA RELEASE OR (INDISCERNIBLE) BUT THAT FURTHERMORE EXTENDED TO THE DOPAMINE NEURONS, I THINK AS I POINTED OUT, SO D2 RECEPTORS IN THESE CELLS ARE PLAYING FUNCTIONALLY A VERY DIFFERENT ROLE THAN THE POST-SYNAPTIC RECEPTORS, BUT ALSO THEY MIGHT BE SIGNALING THROUGH DIFFERENT PATHWAYS AS WELL. WAS THAT YOUR QUESTION, WHETHER THEY SIGNAL DIFFERENTLY? >> NO, WHICH ONES DO YOU THINK ARE MORE IMPORTANT OR OF THE SAME IMPORTANCE FOR THE -- (INAUDIBLE). >> OH, OKAY. SO IN THE OTHER RECEPTOR KNOCKOUT, SORRY I MISUNDERSTOOD YOUR QUESTION, IN THE OTHER RECEPTOR KNOCKOUT, SO WE'RE DOWN REGULATING SELECTIVELY OR REDUCING LEVELS OF D2 RECEPTORS ON THE DOPAMINERGIC NEURONS. >> YES. >> HOWEVER, AT THAT POINT NOT A LOT OF RESCUE WAS DONE TO KIND OF CONFIRM WHETHER THAT WAS SUFFICIENT TO CAUSE THE CHANGE WHICH WOULD BE SOMETHING IMPORTANT TO REVIVE, BUT BECAUSE WE HAVE VERY GOOD EVIDENCE THAT THESE EFFECTS ARE MEDIATED BY ENHANCED DOPAMINE AND SO ON WE THINK THEY ARE LARGELY RESPONSIBLE BUT I THINK THE RESCUE EXPERIMENTS WOULD BE THE WAY TO GO TO CONFIRM THAT. THANK YOU. >> SO LET'S THANK DR. ALVAREZ FOR A TERRIFIC LECTURE. [APPLAUSE] AND I'M SURE THAT THE SHIER AMONG YOU CAN COME UP AFTER THE TALK AND ASK YOUR QUESTIONS. >> THANK YOU SO MUCH. [END OF PROGRAM]