BSSR Lecture Series: Regulation of the dopaminergic reward circuit and manic-like behavior


Uploaded by NIHOD on 11.05.2012

Transcript:
>>> GOOD AFTERNOON.
THANK YOU FOR BEING HERE.
I'D LIKE TO WELCOME YOU TO
TODAY'S BEHAVIORAL AND SOCIAL
SCIENCES RESEARCH LECTURE.
TODAY WE ARE GOING ON HAVE
COLLEEN McCLUNG SPEAKING.
SHE IS A MOLECULAR BIOLOGIST WHO
STUDIED COMPLEX PSYCHIATRIC
DISEASES AND DRUG ADDICTION.
SHE STARTED HER CAREER AS A FROM
2005-2011 WAS AN ASSISTANT
PROFESSOR IN THE PSYCHIATRY
DEPARTMENT FOR NEUROSCIENCE AT
UT SOUTHWESTERN AND SHE MOST
RECENTLY MOVED TO THE UNIVERSITY
OF PITTSBURGH SCHOOL OF MEDICINE
AS ASSOCIATE PROFESSOR IN THE
DEPARTMENT OF PSYCHIATRY.
SHE PUBLISHED SEVERAL HIGH
PROFILE PAPERS AND RECEIVED
FUNDING FROM SEVERAL NIHICs
INCLUDING NIDA AND NIMDS AND
RECEIVED SEVERAL AWARDS
INCLUDING THE PRESIDENT'S
RESEARCH COUNCIL, DISTINGUISHED
YOUNG INVESTIGATOR AWARD AND
RECEIVED AN HONORABLE MENTION
FROM THE FRIEDMAN AWARD FOR
BASIC RESEARCH AT NARSAD.
AND SO, OVER ALL, THE GOAL OF
HER RESEARCH IS TO UNDERSTAND
THE MECHANISMS BY WHICH
CIRCADIAN GENES REGULATE MOOD
AND REWARD AND DEVELOP NOVEL
THERAPIES FOR PSYCHIATRIC
DISEASES.
AND I'LL TURN IT OVER TO HER NOW
TO TALK ABOUT HER TALK TODAY.
SO PLEASE JOIN ME IN WELCOMING
HER.
[APPLAUSE]
>> THANK YOU.
NICE TO BE HERE AT THE NIH.
AND WE RECENTLY MOVED THIS
SUMMER, ACTUALLY, FROM UT
SOUTHWESTERN MEDICAL CENTER AT
UNIVERSITY OF PITTSBURGH SCHOOL
OF MEDICINE AND SO WE ARE
STARTING NEW RESEARCH THERE,
WHICH IS VERY EXCITING.
BUT TODAY I'M GOING TO TELL YOU
ABOUT SOME OF OUR WORK ON THE
CLOCK GENE AND HOW IT'S INVOLVED
IN THE REGULATION OF MOOD AND
REWARD AND MANIC-LIKE BEHAVIORS.
SO, THE CLOCK GENE IS A CENTRAL
REGULATOR OF CIRCADIAN RHYTHMS
AND CIRCADIAN RHYTHMS ARE
ESSENTIALLY A PROCESS THAT GOES
OVER 24 HOURS.
IT'S OUR 24-HOUR INTERNAL
BIOLOGICAL CLOCK WHICH CONTROLS
A BUNCH OF DIFFERENT THINGS,
INCLUDING SLEEP, WEIGHT, BODY
TEMP, BLOOD PRESSURE, EVEN BOWEL
MOVEMENTS, ALERTNESS,
COORDINATION.
ALL OF THESE THINGS ARE
REGULATED OVER A 24-HOUR CYCLE.
AND THE MASTER PACEMAKER CHER
CONTROLS CIRCADIAN RHYTHMS IS
LOCATED IN A PART OF THE BRAIN
CALLED THE SUPER CASMATIC
NUCLEUS, WHICH IS CONTROLLED
DIRECTLY BY LIGHT THROUGH THE
RETINA.
AND THIS LEADS TO
SYNCHRONIZATION OF RHYTHMS
THROUGHOUT THE BRAIN AND THE
REST OF THE BODY.
AND WHILE THIS IS THE MASTER
PACEMAKER IN THE BRAIN,
ESSENTIALLY EVERY CELL IN THE
BRAIN AND EVERY CELL IN THE BODY
CONTAINS ITS OWNER IS CADIAN
CLOCK WHICH CAN BE SYNCHRONIZED
OR DESYNCHRONIZED AND THE
PRESENCE OF STIMULI LIKE FOOD OR
DRUGS OF ABUSE OR OTHER THINGS
THAT MIGHT RESET OR DESINK NICE
THE CIRCADIAN CLOCK.
AND THE MOLECULAR CLOCK IS
COMPOSED OF A TRANSCRIPTIONAL
FEEDBACK LOOP GENERALLY
REGULATED BY THE CLOCK'S PROTEIN
WHICH BINDS TO BMAL1 AND BINDS
TO THE EBOC SEQUENCE IN A NUMBER
OF DIFFERENT GENES, INCLUDING
THE PERIOD JETSTREAMS AND THE
CRYPTO CHROME GENES AND THEN
THESE PROTEINS WILL BIND
TOGETHER.
THEY ARE MODIFIED BY SEVERAL
POSTTRANSLATIONAL MODIFICATIONS.
THEY GO BACK INTO THE NUCLEUS
AND INHIBIT THE ACTIVITY OF
CLOCK AND BMAL1.
SO THIS SETS UP A VERY NICE
TRANSCRIPTIONAL TRANSLATIONAL
FEEDBACK LOOP WHICH CYCLES OVER
THE COURSE OF 24 HOURS.
AND THERE ARE OTHER GENES THAT
ARE NOW KNOWN TO BE INVOLVED IN
THIS, INCLUDING RURAL ALPHA,
MPSA2, WHICH ALSO AID IN THE
TIMING OF THIS CLOCK.
BUT TODAY I'M GOING FOCUS MOSTLY
ON THIS CENTRAL REGULATOR HERE,
THIS CLOCK.
AND THESE RHYTHMS CONTROL LOTS
OF DIFFERENT THINGS AS I
MENTIONED BEFORE.
AND WE KNOW THAT DISRUPTIONS IN
CIRCADIAN RHYTHMS ARE VERY OR
CAN CAUSE VERY SEVERE HEALTH
PROBLEMS, INCLUDING JET LAG,
SLEEP PROBLEMS, AND THEY EVEN IN
CREASE THE RISK FOR CANCER,
HEART DISEASE AND OBESITY.
SO DISRUPTIONS OF THIS NATURALLY
OCCURRING CIRCADIAN CYCLE CAN
REALLY HAVE PROFOUND IMPACTS ON
HUMAN HEALTH.
AND WE KNOW FROM A LOT OF WORK
IN THE CLINIC THAT PEOPLE WITH
MOOD DISORDERS LIKE MAJOR
DEPRESSION AND BIPOLAR DISORDER
AND SEASONAL EFFECTIVE DISORDER,
HAVE VERY SERIOUSLY DISRUPTED
CIRCADIAN RHYTHMS.
SO BIPOLAR DISORDER IS
ASSOCIATED WITH MAJOR
CORRUPTIONS AND SLEEP AND
ACTIVITY AND VERY PROFOUND AND
ONE OF THE MAJOR DIAGNOSTIC
TOOLS FOR USE IN THESE DISEASES.
WE KNOW THAT CHANGES IN SCHEDULE
CAN PRECIPITATE, ESPECIALLY
MANIC EPISODES IN BIPOLAR
PATIENTS, SO SOMEBODY MAYBE
GOING ALONG FINE AND THEN THEY
MAY WORK A DIFFERENT SHIFT OR
TRAVEL OR SOMETHING AND THIS
WILL SET THEM OFF INTO A MANIC
EPISODE.
DEPRESSION IS ALSO DIJOURNAL,
SOCIETY WORST SYMPTOMS OCCUR IN
THE MORNING.
IT'S OFTEN SEASONAL.
SEASONAL EFFECTIVE DISORDER IS
THE MOST COMMON MOOD DISORDER.
AND DEPRESSION OCCURS MORE
FREQUENTLY IN AREAS OF THE WORLD
WHERE THERE IS LITTLE DAYLIGHT
FOR LONG PERIODS OF TIME LIKE
ALASKA.
WE KNOW THAT PEOPLE WITH A
PREFERENCE TOWARDS EVENINGNESS,
SO NIGHT OWLS VERSUS MORNING
LACKS ARE MORE SUSCEPTIBLE TO
DEPRESSION.
A VAST MAJORITY OF BIPOLAR
PATIENTS ARE EVENING TYPES
VERSUS MORNING TYPES.
AND NOW THERE HAS BEEN A NUMBER
OF CIRCADIAN GENE THAT IS HAVE
BEEN FOUND IN GENETIC STUDIES,
WHICH HAVE SNPS OR DIFFERENT
POLYMORPHISMS THAT ASSOCIATE
WITH PRIMARILY WITH BIPOLAR
DISORDER, BUT ALSO WITH SEASONAL
EFFECTIVE DISORDER AND
DEPRESSION.
AND THE CLOCK PROTEIN IN
PARTICULAR, THERE ARE SEVERAL
SNPS IN THE CLOCK GENE
ASSOCIATED WITH THE PREVALENCE
FOR BIPOLAR DISORDER AND
SEVERITY OF SYMPTOMS AND BIPOLAR
DISORDER.
WE ALSO KNOW THAT MOST OF THE
TREATMENTS FOR DEPRESSION ARE
EFFECTIVE CIRCADIAN CLOCK AND
THESE INCLUDE THINGS LIKE BRIGHT
LIGHT THERAPY SHOWN HERE WHERE
THE PATIENT WILL SIT IN FRONT OF
A LIGHT FOR 30 MINUTES IN THE
MORNING AND THIS WILL SHIFT THE
CIRCADIAN CLOCK AND HELP TO
TREAT SEASONAL EFFECTIVE
DISORDER.
TOTAL SLEEP DEPRIVATION IS
ACTUALLY A VERY EFFECTIVE
SHORT-TERM ANTIDEPRESSANT.
UNFORTUNATELY ONLY WORKS UNTIL
PEOPLE GO TO SLEEP AGAIN.
BUT IT WORKS PRETTY WELL IN THE
ER.
SOCIAL RHYTHM THERAPY WAS
PIONEERED BY DAVID CUP AND ALAN
FRANK AT THE UNIVERSITY OF
PITTSBURGH WHERE THEY PUT
BIPOLAR PATIENTS ON VERY STRICT
CIRCADIAN SCHEDULES SO VERY
STRICT SLEEP-WAKE AND SOCIAL AND
EATING SCHEDULES.
AND THIS HELPS TO PREVENT THE
APPEARANCE OF NEW MOOD-RELATED
EPISODES.
MELATONIN THERAPY HAS BEEN USED
TO SOME EXTENT, ALTHOUGH
MELATONIN IS NOT SUCH A GREAT
ANTIDEPRESSANT.
IT'S REALLY NOT AN
ANTIDEPRESSANT AT ALL.
IT DOES HELP IN SOME OF THE
SLEEP SYMPTOMS.
BUT THERE IS SAY NEW DRUG, AG
MEL TIN, APPROVED FOR DEPRESSION
IN EUROPE AND THE REST OF THE
WORLD BASICALLY, WHICH IS A
MELATONIN RECEPTTORAGONIST WHICH
IS VERY EFFECTIVE FOR TREATING
DEPRESSION.
AS WELL DRUGS LIKE LITHEIUM AND
SSRIs, SEROTONIN REUPTAKE
INHIBITORS WILL PRO PHONEDLY
AFFECT CIRCADIAN RHYTHM.
LITHEIUM SHORTENS IT AND SSRIs
LENGTHENS THE CIRCADIAN RHYTHM.
WE ALSO KNOW THAT PEOPLE WITH
DRUG ADDICTION, PROPS WITH
ADDICTIVE DISORDERS HAVE
DISRUPTED CIRCADIAN RHYTHMS AND
OUR LAB STUDIES MOOD DISORDERS
AND DRUG ADDICTION.
AND I WILL TALK MOSTLY ABOUT THE
MOOD DISORDERS BUT I'LL THROW IN
A LITTLE BIT ABOUT ADDICTION.
THESE ARE THE THREE DIFFERENT
WAYS OUR LAB IS STUDYING THE
IMPACT OF CIRCADIAN RHYTHM
DISRUPTIONS AND CIRCADIAN GENE
DISRUPTIONS.
PEOPLE WITH CIRCADIAN RHYTHM
DISRUPTIONS SEEM TO BE MORE
VULNERABLE TO ADDICTION AND MORE
VULNERABLE TO MOOD DISORDERS AND
OFTEN CO-MORBID.
DRUGS OF ABUSE CAN EN TRAIN
CIRCADIAN RHYTHMS SUCH THAT THE
DRUG ANTICIPATED BY THE BRAIN
LEADING TO INCREASED CRAVING AND
DRUG SEEKING.
SO FOR EXAMPLE, IF YOU HAVE
COCKTAILS EVERY DAY AT 5:00,
YOUR BRAIN REWARDS SYSTEM WILL
START TO ANTICIPATE THOSE
COCKTAILS AT 5:00 AND ABOUT 4 OR
4:30 YOU MAY START TO WANT THEM,
CRAVE THEM.
IT'S BECAUSE THE REWARD SYSTEM
IS BEING SET BY THAT DRUG.
ALSO, LONG TERM EXPOSE TOWER
DRUGS OF USE CAN LEAD TO
DISRUPTIONS IN THE CIRCADIAN
SYSTEM.
WHICH LEADS TO LONG LASTING MOOD
AND SLEEP PROPS WHICH MIGHT
CONTRIBUTE TO RELAPSE AND THIS
IS SEEN A LOT WITH ALCOHOLICS.
SO HOW DOES THE CIRCADIAN SYSTEM
INFLUENCE MOOD AND REWARD?
WE STUDIED THIS AND LOOKING AT
MOUSE MODELS.
AND MOSTLY YOU PROBABLY KNOW
THIS, BUT BASICALLY THESE ARE
SOME OF THE TESTS THAT WE USE TO
DETERMINE IF A MOUSE IS ANXIOUS
OR DEPRESSED OR LIKES DRUGS OR
ANY OF THESE THINGS.
SO WE USE TESTS LIKE THE LEARN
HELPLESSNESS TEST TO LOOK AT
BEHAVIORAL DESPAIR, MODELS OF
DEPRESSION.
WE USE TESTS LIKE THE OPEN FIELD
AND ELEVATED PLUS MAZE TO LOOK
AT ANXIETY AND THINGS LIKE
CONDITION PLACE PREFERENCE AND
SELF ADMINISTRATION TO LOOK AT
DRUG/REWARD.
SO ALL OF THESE HELP US TO
DETERMINE WHAT IS GOING ON WITH
OUR MOUSE.
SO WHAT ABOUT MICE WITH A
MUTATION IN THE CLOCK GENE?
WE WANTED TO KNOW WHAT KIND OF
BEHAVIORAL PHENOTYPES THEY WOULD
HAVE.
A MOUSE WAS CREATED WITH A
MUTATION IN THE CLOCK GENE WHICH
CREATES A DOMINANT NEGATIVE
PROTEIN.
THESE ARE THE CLOCK DELTA 19
MICE.
SO WE WANTED TO PUT THEM THROUGH
A BATTERY OF TESTS TO SEE WHAT
SORT OF BEHAVIORAL PHENOTYPES
THEY HAD.
AND VERY INTERESTINGLY, WE FOUND
THAT THESE MICE BASICALLY IN
EVERY WAY WE COULD TEST THEM,
THEY REALLY RESEMBLED BIPOLAR
PATIENTS BUT SPECIFICALLY IN THE
MANIC STATE.
SO, THIS IS JUST A COMPARISON
HERE SO THEY WERE VERY
HYPERACTIVE.
THEY SLEEP LESS THAN WILDTYPE
MICE.
THEY ARE LESS DEPRESSED THAN THE
BEHAVIORAL MODELS I MENTIONED.
THEY HAVE LOWER LEVELS OF
ANXIETY SO SORT OF INCREASED
RISK TAKING BEHAVIOR, MORE
EXPLORETORY BEHAVIOR.
AND THEY ARE ALSO MORE SENSITIVE
TO THE REWARDING AFFECTS OF
PRETTY MUCH EVERYTHING, COCAINE,
SUCROSE, BRAIN STIMULATION.
THEY FIND THESE THINGS REALLY,
REALLY REWARDING.
AND WHEN WE GAVE THEM LITHEIUM,
CHRONICALLY, THIS WAS ABLE TO
REVERSE THE MAJORITY OF THEIR
PHENOTYPES.
THEY MADE A VERY NICE MODEL OF
HUMAN MANIA.
WE HAVE GONE ON TO DO A FEW MORE
ADDICTION STUDIES WITH THESE
MICE.
WE DID A SELF ADMINISTRATION
STUDY AND FOUND THAT THIS SINGLE
POINT MUTATION IN THE CLOCK GENE
ACTUALLY MAKES MICE MORE
VULNERABLE TO THE COCAINE
ADDICTION WITH THE SELF
ADMINISTRATION.
IN THE INTEREST OF TIME, I WON'T
GO THROUGH ALL OF THIS BUT
ESSENTIALLY THESE MICE WILL NOW
TAKE COCAINE ESPECIALLY DURING
THE DAY WHEN WILDTYPE MICE ON
THE SAME BACKGROUND WILL NOT
TAKE COCAINE AT ALL AT THIS TIME
POINT.
THEY HAVE AN INCREASE IN
INFUSIONS PER SESSION AND IT'S
NOT JUST THAT THEY ARE RUNNING
AROUND PRESSING LEVERS WILDLY.
THEY DON'T PRESS THE INACTIVE
LEVER.
THEY HAVE A SELECTION FOR THE
ACTIVE LEVER.
AND THEY FIND BASICALLY SELF
ADMINISTER AT A GREATER EXTENT
TO ALMOST EVERY DOSE.
AND THEY'LL WORK HARDER TO
OBTAIN A COCAINE.
SO THEY WILL PRESS THE LEVER
MORE TIMES TO GET A SINGLE
INFUSION OF COCAINE.
SO, ALL OF THIS TAKEN TOGETHER
BASICALLY SUGGESTS THAT A
MUTATION IN THE CLOCK GENE LEADS
TO A REAL VULNERABILITY FOR
ADDICTION.
WE HAVE ALSO LOOKED AT ALCOHOL.
SO WE WANTED TO FINISH THIS WAS
SPECIFIC TO STIMULANTS AND
BASICALLY THEY SHOW INCREASE IN
ETHANOL PREFERENCE AS WELL SO
THIS IS PREFERENCE AND
CONSUMPTION OVER WILDTYPE MICE.
SO NOT JUST STIMULANTS BUT
DEPRESSANTS AS WELL.
SO, THESE BEHAVIORAL PHENOTYPES
BASICALLY LED US TO WONDER WHAT
COULD BE GOING ON IN THEIR BRAIN
AND WE DECIDED TO FOCUS ON THE
DOPAMINE SYSTEM WHICH IS
BASICALLY THE CIRCUIT BETWEEN
THE VENTRAL AREA AND THE NUCLEUS
SUCCUMB BENS AND DOPAMINERGIC
REWARD CIRCUIT TO SEE WHAT MIGHT
BE GOING ON IN THIS CIRCUIT IN
THE BRAINS OF THE CLOCK DELTA 19
MICE.
AND SO, WHEN WE RECORDED FROM
THE DOPAMINE NEURONS, THIS IS --
THESE ARE SLICE RECORDINGS, WHAT
WE FOUND IS THAT THE CLOCK
MUTANTS HAVE AN INCREASE IN
DOPAMINE SELF FIRING AS SHOWN
HERE, AND WHEN WE GAVE THEM
LITHEIUM, THIS RETURNED THEIR
FIRING RATE TO THAT OF WILDTYPE
MICE.
AND AS YOU CAN SEE HERE,
WILDTYPE MICE LITHEIUM HAS NO
AFFECT ON THEIR SEVERAL FIRING.
SO THE LITHEIUM IS ALTERING THE
DOPAMINERGIC FIRING RATE IN THE
CLOCK MUTANT MICE.
SO THESE MICE SEEM TO BE
HYPERDOPAMINERGIC.
WE HAVE ALSO DONE THIS IN-VIVO
AND THEY HAVE INCREASED SELF
BURSTING AS WELL AS IN-VIVO.
SO WE WANTED TO KNOW IF WE COULD
RESCUE THEIR BEHAVIORAL
PHENOTYPES BY PUTTING A CLOCK,
FUNCTIONAL CLOCK PROTEIN
SPECIFICALLY INTO THE VTA OF THE
CLOCK MUTANT MICE.
AND TO DO THIS, WE USED AN AAV
VIRUS WHERE WE PUT IN A
FUNCTIONAL CLOCK PROTEIN,
INJECTED THAT INTO THE VTA AND
THIS WAS ABLE TO REVERSE THEIR
LOCAL MOTOR PHENOTYPE SO HERE WE
HAVE A MUTANT WITH JUST A VIRUS
AND GFP AND THE MUTANT WITH THE
FUNCTIONAL CLOCK.
YOU CAN SEE COMPARED TO THE GFP
YOU PUT A FUNCTIONAL CLOCK BACK
IN THE VTA AND YOU GET NORMAL
LOCAL MOTOR BEHAVIOR AS WELL WE
SAW NORMALIZATION OF BEHAVIOR IN
THE OPEN FIELD.
SO CLOCK IS REALLY FUNGING IN
THE VTA TO CONTROL SOME OF THESE
BEHAVIORS.
WE DID THE OPPOSITE EXPERIMENT
WHERE WE WANTED TO KNOCK DOWN
CLOCK SPECIFICALLY IN THE VTA OF
OTHERWISE WILDTYPE MICE.
AGAIN, WE TOOK AN AAV VECTOR AND
WE CREATED A SHORT HAIR PIN RNA
WHICH MATCHED THE SEQUENCE OF
THE CLOCK GENE AND PUT THAT INTO
THE VTA OF OTHERWISE WILDTYPE
MICE.
AND WHEN WE RECORDED FROM THESE
NEURONS, WE SAW ALSO THAT
KNOCKING DOWN CLOCK IN THE VTA
WAS SUFFICIENT TO INCREASE
DOPAMINERGIC SELF FIRING AS
SHOWN HERE.
BOTH COMPARED TO GFP MEGGATIVE
CELLS RIGHT NEXT TO IT AND WITH
AN AAB SCRAMBLED CONTROL.
SO THIS WAS SIMILAR TO WHAT WE
SAW IN THE CLOCK MUTANT MICE.
AND KNOCKING DOWN CLOCK IN THE
VTA RECAPITULATED SOME OF THE
BEHAVIORAL AFFECTS WE SEE IN THE
CLOCK DELTA 19 SO THE
HYPERACTIVITY AND CHANGES IN THE
ELEVATED PLUS MAZE, DARK OPEN
FIELD, THEY BECAME LESS ANXIOUS
IN ALL OF THESE DIFFERENT
MEASURES.
SO, LOOKS LIKE THE CLOCK DELTA
19 MICE.
HOWEVER, TO OUR SURPRISE, WE
ACTUALLY SAW AN INCREASE IN
DEPRESSION-RELATED BEHAVIOR.
SO THIS WAS SHOWN IN THE LATENCY
IMMONTHABILITY IN THE POOR SWIM
TEST AND THE FAILURE TO ESCAPE
IN THE HELPLESSNESS TEST.
THIS IS THOUGHING THAT A KNOCK
DOWN OF CLOCK IN THE VTA LEADS
TO GREATER LEVELS OF DEPRESSION.
SO THIS WAS OPPOSITE TO WHAT WE
SAW IN THE CLOCK DELTA 19 MICE,
WHICH WAS REALLY INTERESTING
BECAUSE OF COURSE BIPOLAR
PATIENTS HAVE BOUTS OF BOTH
MANIA AND DEPRESSION.
SO HERE IS A DIFFERENT
MANIPULATION OF CLOCK LEADING TO
DECREASED DEPRESSION OR
INCREASED DEPRESSION.
AND AS YOU REMEMBER THESE MICE
ALSO HAD AN INCREASE OF
DOPAMINERGIC ACTIVITY AND WE
ALSO FOUND THIS INTERESTING
BECAUSE ERIC NECESSARILER'S
GROUP HAD RECENTLY SHOWN THAT
MICE THAT HAVE A DEPRESSION-LIKE
PHENOTYPE FOLLOWING CHRONIC
SOCIAL STRESS WHERE MICE ARE
BEATEN UP DAY AFTER DAY AFTER
DAY, MICE THAT BECOME
SUSCEPTIBLE TO THIS SO THEY SHOW
A DEPRESSION-LIKE PHENOTYPE AT
THE END OF THIS PARADIGM ALSO
HAVE INCREASE IN DOPAMINE SELF
FIRING VERSUS MICE THAT WERE
UNSUSCEPTIBLE OR RESILIENT TO
THIS PARADIGM.
SO WHAT THIS TELLS US IS THAT
INCREASED DOPAMINE SELF FIRING
ASSOCIATED WITH MANIC-LIKE
PHENOTYPE, DEPRESSION-LIKE
PHENOTYPE AND SOME KIND OF MIX
PHENOTYPE WHERE WE HAVE LESS
ANXIETY BUT INCREASED
DEPRESSION.
WE ARE TRYING TO UNDERSTAND THE
IMPORTANCE OF THIS CHANGE IN
FIRING ACROSS ALL OF THESE
DIFFERENT MOOD STAGES.
INTERESTINGLY, WE ALSO, WHEN WE
KNOCKED DOWN CLOCK IN THE VTA WE
SAW INCREASE IN ALCOHOL
PREFERENCE AND ALCOHOL
CONSUMPTION SIMILAR TO THE CLOCK
MUTANT MICE.
SO AGAIN, KNOCKING DOWN CLOCK IN
A VTA INCREASED ALCOHOL INTAKE.
SO HOW IMPORTANT WAS DOPAMINE IN
THE DEVELOPMENT OF THE
MANIC-LIKE BEHAVIOR AND THE
REVERSAL BY LITHEIUM?
SO THIS IS SHOWING THAT THESE
THINGS ARE ASSOCIATED BUT WE
WANTED TO LOOK MORE CLOSELY AT
THE ROLE OF DOPAMINE IN THESE
BEHAVIORS.
SO AGAIN WE USED A VIRUS TO
CHANGE THE FIRING RATE OF THE
DOPAMINE NEURONS IN THE CLOCK
MUTANT MICE.
SO THIS IS A POTASSIUM CHANNEL
VIRUS T EXPRESSES A POTASSIUM
CHANNEL USED BY SEVERAL
DIFFERENT LABS IN THE PAST TO
MANIPULATE CELL FIRING.
AND WE INJECTED INTO THE VTA AND
SHOWED THAT THE INFECTED CELLS
HAVE LOWER FIRING RATES.
SO HAD IS SORT OF MIMICKING THE
AFFECTS OF LITHEIUM AS YOU
RECALL ON THE ACTIVITY OF THE
DOPAMINE NEURONS.
AND WE FOUND THAT THIS WAS
SUFFICIENT TO DECREASE THEIR
HYPERACTIVITY AND CHANGE THEIR
LEVELS OF ANXIETY.
SO, THIS LED TO A NORMALIZATION
OF ANXIETY SO THEY ARE BECOMING
MORE ANXIOUS, MORE LIKE WILDTYPE
MICE AND THE DARK LIGHT AND THE
ELEVATED PLUS MAZE.
HOWEVER, WHEN WE MEASURED
DEPRESSION-RELATED BEHAVIORS, WE
SAW NO CHANGE IN
DEPRESSION-RELATED BEHAVIORS.
SO CHANGING THE FIRING RATE OF
DOPA MANY NEURONS WAS SUFFICIENT
TO CHANGE THE ANXIETY-RELATED
PHENOTYPES BUT NOT THE
DEPRESSION-RELATED PHENOTYPES.
SO WE ALSO WANTED TO KNOW IF
DOPAMINE SELF FIRING WAS CHANGED
OVER THE COURSE OF THE 24-HOUR
PERIOD IN THE CLOCK MUTANT MICE,
IF THERE WAS A TIME OF DAY MAYBE
WHERE THE DIFFERENCE WAS MOST
PRONOUNCED.
AND SO TO DO THIS, WE
COLLABORATED WITH DUKE
UNIVERSITY AND DID IN-VIVO
RECORDINGS WHILE ANIMALS WERE IN
REM SLEEP.
SO HERE THE CLOCK MUTANT MICE --
WILDTYPE MICE HAVE THIS NICE
RHYTHM IN REM SLEEP WHERE THEY
ARE HAVING THE MOST SLEEP DURING
THE DAY AND LESS SLEEP DURING
THE NIGHT.
HOWEVER THE CLOCK MUTANTS LOSE
THEIR RHYTHM IN REM SLEEP BUT
THEY STILL HAVE SOME BOUTS OF
REM SLEEP.
AND WHEN WE MEASURED DOPAMINE
SELF FIRING DURING THEIR SLEEP
BOUTS, WE SAW THAT THERE WAS
MUCH MORE OF INCREASE DURING THE
DAY THAN DURING THE NIGHT,
ALTHOUGH IT IS GENERALLY
INCREASED OVER THAT OF WILDTYPE.
SO THE CLOCK MUTANTS ARE HAVING
MOST PRONOUNCED AFFECTS OF
DOPAMINE DURING THE DAY WHEN
THEY SHOULD BE SLEEPING.
AND SO WE WONDERED IF WE WERE TO
ALTER DAYTIME VTA FIRING IN A
WILDTYPE MOUSE, COULD WE MAKE
THIS MOUSE MANIC?
SO TO DO THIS, WE COLLABORATED
WITH CARL AT STAMFORD UNIVERSITY
AND WE ARE USING A TECHNIQUE
CALLED OPT GENETICS WHERE WE PUT
A CHANNEL OPPOSITE IN, A
LIGHT-ACTIVATED CHANNEL DIRECTLY
INTO THE VTA OF MICE AND IN THIS
PARTICULAR STUDY WE USED THCRE
MICE, SO MICE WHICH HAVE THE
COUNTRY MICE DRIVEN BY THE
TYROSINE HYDROXYLASE PROMOTOR
WHICH ALLOWS US TO EXPRESS THIS
ONLY IN DOPAMINE NEURONS IN THE
VTA.
AND WE WANTED TO DO A CHRONIC
STIMULATION.
MOST STUDIES HAVE USED ACUTE BUT
WE WANTED TO DO A CHRONIC
STIMULATION TO KIND OF MIMIC
WHAT WAS GOING ON IN THE CLOCK
MUTANT MICE.
SO WE USED A NOVEL OPPOSITE IN
THEY JUST DELIVERED --
OPSIN -- WHICH HAS A VERY SLOW
ACTIVATING ACTIVITY.
AND BASICALLY JUST MAKES THE
CELL MORE PERMISSIBLE TO
ACTIVATION OVER LONG PERIODS OF
TIME.
AND SO WHAT WE DID WAS WE DID
SURGERIES.
SO WE INJECTED THE AAV VIRUS
WITH THE STEP FUNCTION OPSIN IN
THE VTA OF THE THCRE MICE AND
WAITED FOR FOUR WEEKS TO ALLOW
EXPRESSION.
AND THEN WE DID A SEVEN-DAY
CHRONIC STIMULATION PARADIGM
WHERE WE GAVE THEM LIGHT PULSES
OVER AN HOUR A DAY JUST DURING
THE DAYTIME FOR SEVEN DAYS.
THEN WE DID THE ELEVATED PLUS
MAZE, OPEN FIELD, SUSPENSION AND
WE GAVE BOOSTER STIMULATION IN
BETWEEN SO WE WOULD KEEP THAT
LEVEL OF DOPAMINE UP.
AND THE CONTROL GROUP HAD ALL
THE SAME PROCEDURES BUT NO LIGHT
DURING THAT SEVEN DAY
STIMULATION.
SO WE WANTED TO KNOW HOW THESE
MICE ARE BEHAVING IN BEHAVIORAL
TESTS.
IMPORTANTLY, THIS CONIC --
CHRONIC STIMULATION PATTERN HAD
NO AFFECTS ON GENERAL LOCOMOTOR
ACTIVITIES SO IT WAS UNAFFECTED,
IT WAS NORMAL.
HOWEVER, WE LOOKED AT THE
ELEVATED PLUS MAZE AND SHOWED
INCREASE IN OPEN-ARMED PINE
WHICH IS INDICATIVE OF LESS
ANXIETY.
AND INCREASED TIME IN THE CENTER
OF THE OPEN FIELD AND A DECREASE
IN THE LATENCY TO ENTER THE OPEN
FIELD.
SO ESSENTIALLY CHRONIC
STIMULATION OF VTA DOPAMINE IN
OTHERWISE WILDTYPE MICE DURING
THE DAY LEADS TO LESS ANXIETY --
EXCUSE ME, INCREASED EXPLORETORY
BEHAVIOR BUT NO CHANGE IN
GENERAL MOTION AND WHEN WE
LOOKED AT THE TAIL SUSPENSION
TEST WHICH IS THOUGHT TO BE A
MEASURE OF DEPRESSION RELATED
BEHAVIOR ALTHOUGH THAT IS
DEBATED, WE FOUND NO CHANGE.
SO AGAIN, SIMILAR TO THE AFFECTS
WE GOT WITH THE POTASSIUM
CHANNEL STIMULATION ARE THE
POTASSIUM CHANNEL REDUCTION IN
VTA SELF FIRING WHERE WE FOUND
NO CHANGE IN DEPRESSION-RELATED
BEHAVIOR, STIMULATING DOPAMINE
SELF FIRING ALSO LED TO NO
CHANGE IN DEPRESSION-RELATED
BEHAVIOR.
SO BASICALLY THERE IS SOMETHING
GOING ON WITH THE DOPAMINE
NEURONS IN TERMS OF DEPRESSION
BUT THERE IS LIKELY OTHER
CIRCUITS AND OTHER REGIONS
CONTRIBUTING TO THIS EFFECT.
SO WE WANTED TO GET BEYOND JUST
DOPAMINE ITSELF AND LOOK MORE AT
THE OVERALL CIRCUITS.
SO AGAIN, WE COLLABORATED WITH
OTHERS AND WE LOOKED AT THIS
PHENOMENON OF CROSS FREQUENCY
PHASE COUPLING, WHICH IS WHERE
THE AMPLITUDE OF HIGH FREQUENCY
NEUROOSTORY ACTIVITY IS
MODULATED BY LOW FREQUENCY
OSCILLATION.
SO ESSENTIALLY, THIS IS SHOWN
HERE WHERE THE HIGH, GAMMA,
OSCILLATIONS WHICH ARE IN RED,
WILL MATCH UP WITH THE GREEN,
LOW FREQUENCY OSCILLATIONS, IN A
SYNCHRONOUS WAY.
AND THIS IS THOUGHT TO BE REALLY
INVOLVED IN HIGHER COGNITION AND
HIGHER SYNCING BASICALLY WHEN
YOU HAVE THESE TYPES OF
SYNCHRONIZATIONS.
AND YOU CAN SEE WHERE IT IS OFF
HERE WHETHER THERE IS NO
COUPLING OF THE TWO.
AND WE LOOKED WITHIN THE NUCLEUS
SUCCUMB BENS AND PRELIMBIC
CORTEX AND THE VTA IN FREELY
MOVING ANIMALS, SO THEY ARE
IMPLANTED WITH TET RODES BUT
THEY ARE IN VARIOUS REGIONS BUT
THEY ARE MOVING AROUND FREELY.
AND WHAT WE FOUND WAS THAT IN
WILDTYPE MICE, THERE IS A
NEGATIVE CORRELATION BETWEEN THE
AMOUNT OF COUPLING THAT IS SEEN
IN THE NUCLEUS SUCCUMB BENS AND
THE AMOUNT THAT THE ANIMAL
TRAVELS IN THE OPEN FIELD.
SO ESSENTIALLY THE LES COUPLING
THEY HAVE, THE MORE LIKELY THEY
ARE GOING TO RUN AROUND IN THE
CENTER OF AN OPEN FIELD SO IT
WILL BE LIKE A LESS ANXIETY THEY
MIGHT HAVE AND THE CLOCK
MUTANTS, THERE IS NO CORRELATION
AT ALL.
IT'S A FLATLINE.
THEY HAVE VERY LITTLE COUPLING
BETWEEN THESE OSCILLATIONS AND
THE NUCLEUS SUCCUMB BENS.
AND WHEN WE GIVE THEM LITHEIUM,
THIS IS ABLE TO RESCUE THE
COUPLING NOW WITHIN THE NUCLEUS
SUCCUMB BENS.
SO SOMEHOW LITHEIUM IS ABLE TO
OVERCOME THIS LACK OF
SINKIZATION AND BRING THINGS
BACK TO WHERE THEY SHOULD BE.
SO WE ALSO LOOKED AT SINKIZATION
NOT ONLY WITHIN A BRAIN REGION
BUT ALSO BETWEEN BRAIN REGIONS
SO WITHIN A WHOLE CIRCUIT.
AND WE WANTED TO LOOK IN WHILE
THE ANIMALS WERE DOING AN
ANXIETY-RELATED PARADIGM.
SO THE ANIMALS WERE DOING AN
ELEVATED ZERO MAZE, SIMILAR TO
ELEVATED PLUS MAZE BUT BASICALLY
JUST IN A ZERO SHAPE.
SO STILL HAS CLOSED ARMS, STILL
HAS OPEN ARMS, BUT IT'S IN A
ZERO SHAPE.
AND WHAT WE REALIZED IS THAT THE
SYNCHRONIZATION BETWEEN
DIFFERENT BRAIN REGIONS,
PARTICULARLY IN THE HIGH
FREQUENCY, THE GAMMAOS LATORY
REGION, WHICH AGAIN IS THOUGHT
TO BE VERY IMPORTANT FOR HIGHER
THINKING, HIGHER REASONING, THAT
THIS BECAME PREDICTIVE OF WHAT
THE ANIMAL WAS GOING TO DO ON
THIS MAZE.
SO, HERE AT TIMES ZERO, IS WHEN
ANIMAL IS INSIDE THE CLOSED ARMS
BUT THEY ARE ABOUT TO MAYBE MAKE
THE DECISION TO GO INTO AN OPEN
ARM, AN ANXIETY-PROVOKING
ENVIRONMENT.
AND WHAT CAN YOU SEE IS WHEN YOU
LOOK BETWEEN THE NUCLEUS SUCCUMB
BENS AND AMYGDALA AND THE VTA OR
JUST THE PREFRONTAL CORTEX, YOU
START TO SEE THESE
SYNCHRONIZATION EVENTS.
SO ANYTHING ABOVE THE RED LINE
IS WHERE YOU'RE GETTING
SYNCHRONIZATION BETWEEN THESE
REGIONS IN FIRING RATES.
AND SO YOU START TO SEE THIS
JUST BEFORE THE ANIMALS ARE
MAKING THE DECISION TO GO OUT
THERE.
AND SO PRESUMABLY THIS IS
INVOLVED IN THE FEAR RESPONSE OR
THEM TRYING TO MAKE THAT
DECISION THAT THEY ARE GOING TO
GO OUT.
AND THE CLOCK MUTANTS ALMOST
COMPLETELY LACK THIS
SYNCHRONIZATION BETWEEN THESE
REGIONS AND OF COURSE THEY JUST
RUN OUT INTO THE OPEN ARM MUCH
MORE FREQUENTLY.
SO WE THANK THIS SYNCHRONIZATION
ACROSS REGION SYSTEMS
PARTICULARLY IMPORTANT IN HIGHER
DECISION-MAKING.
YES?
>> [OFF MIC]
>> YES.
SO I MEAN, BASICALLY HE IS
CREATING A NEED FOR WHERE HE IS
LOOKING AT THE SYNCHRONIZATION
BETWEEN THE GAMMAOSTORY BANDS IN
THE --
AS RECORDING.
SO THE CLOCK GENE SEEMS TO BE
INVOLVED IN NOT ONLY CIRCADIAN
RHYTHM REGULATION BUT ALSO
SYNCHRONIZATION BETWEEN REGIONS
JUST WHILE ANIMALS ARE DOING
NORMAL TASKS.
SO, CLOCK IS A TRANSCRIPTION
FACTOR.
WE WANT TO KNOW WHAT ARE THE
TRANSCRIPTIONAL TARGETS WHICH
MIGHT BE INVOLVED IN ALL OF
THIS?
THE CLOCK IS REGULATING AND THE
VTA NUCLEUS SUCCUMB BENS
CIRCUIT.
SO WE DID A MICROARRAY ANALYSIS
OF THE VTA OF THE CLOCK MUTANT
MICE VERSUS WILDTYPE MICE.
AND WE FOUND A NUMBER OF GENES
THAT WERE DIFFERENTIALLY
REGULATED, INCLUDING GENES THAT
ARE VERY IMPORTANT IN THE
REGULATION OF DOPAMINE
TRANSMISSION SUCH AS TYROSINE
HYDROXYLASE, AND SOME OTHERS.
AND OF COURSE WE FOUND GENES
INVOLVED IN CIRCADIAN RHYTHMS TO
BE REGULATED, WHICH YOU WOULD
EXPECT IN THE CLOCK MUTANT
MOUSE.
SO THAT WAS SORT OF A CONTROL
WHICH WAS NICE.
AND WE HAVE BEGUN TO LOOK AT
SOME OF THESE GENES
INDIVIDUALLY.
I'M ONLY GOING TO TELL BUT ONE
TODAY, WHICH IS --
SO, IT'S ALSO CALLED CCK AND CKK
IS A NEUROPEPTIDE WHICH IS
CORELEASED WITH DOPAMINE WHICH
ACTS TO FEEDBACK AND INHIBIT THE
ACTIVITY OF DOPAMINE NEURONS.
SO IF YOU HAVE LESS CCK, YOU'RE
LIKELY TO HAVE GREATER
DOPAMINERGIC ACTIVITIES.
SO WE DID CHROMATIN
IMMUNOPRECIPITATION ASSAYS USING
ANTIBODY FOR THE CLOCK PROTEIN
AND FOUND CLOCK DIRECTLY
REGULATES THE EXPRESSION OF CCK,
WHICH IS SHOWN HERE.
SO CLOCK IS DIRECTLY BINDING THE
PROMOTOR OF THE CCK GENE.
AND IT IS DOING IT IN A
DEPENDENT FASHION.
SO HERE IN CELL CULTURE WHEN YOU
HAVE A LUCIFERASE REPORTER, YOU
ADD IN CLOCK AND BMAL1 AND YOU
GET AN INCREASE.
THIS TAKES IT AWAY.
SO CLOCK IS BINDING AT THE CCK
PROMOTOR DIRECTLY.
ONE OF THE REASONS WE WERE
REALLY INTERESTED IN CCK IS
BECAUSE WHEN WE LOOKED AT
LITHEIUM TREATMENT, WE SAW THAT
LITHEIUM TREATMENT WAS ABLE TO
BRING LEVELS OF CCK BACK TOWARDS
THAT OF WILDTYPE MICE SO HERE
AGAIN LITHEIUM HAD NO EFFECT ON
THE CCK LEVELS OF THE WILDTYPE
MICE.
HERE IS THE CLOCK MUTANT MICE
THAT HAS A DRAMATIC DECREASE
FROM CCK.
WHEN WE GIVE LITHEIUM IT GOES
BACK TOWARDS NORMAL.
>> [OFF MIC]
>> YES.
SO WE ARE IN THE PROCESS OF
DOING ALL THAT NOW.
WE HAD --
I HAD A GRANT TO LOOK AT THAT.
BASICALLY BUT WE DECIDED TO DO
IT IN A BIG FASHION WHERE WE ARE
LOOKING OVER DIFFERENT TIMES OF
DAY AND AT DIFFERENT BRAIN
REGIONS AND SO WE HAVEN'T
COMPLETED IT YET.
>> [OFF MIC]
>> WE HAVEN'T LOOKED AT THEM YET
BUT WE ARE PLANNING ON DOING
THAT.
WE ALSO HAVE SOME HUMAN TISSUE
FROM YOUR OUR BRAIN BANK AT UT
SOUTHWESTERN.
AND WE FOUND WHEN WE LOOKED AT
CCT IN HUMAN POST MORTEM TISSUE,
THAT SUBJECTS, COMPARED TO
CONTROL SUBJECTS, SUBJECTS THAT
WERE OFF MEDICATION HAD A
DECREASE SIMILAR TO THE CLOCK
MUTANT MICE AND CCK EXPRESSION
AND THOSE ON MEDICATION OF THE
TIME OF DEATH HAD A NORMALIZED
CCK EXPRESSION.
SO THIS WAS VERY NICELY MATCHED
TO WHAT WE SAW IN THE CLOCK
MUTANT MICE WHICH ALSO MADE US
VERY EXITED ABOUT CCK.
SO WE WONDERED HOW LITHIUM WAS
ABLE TO REVERSE THE EXPRESSION
OF CCK AND BRING IT BACK UP TO
NORMAL IN THE CLOCK MUTANT MICE
AND THERE ARE A COUPLE OF
DIFFERENT WAYS THIS COULD
HAPPEN.
WE FIRST LOOKED AT TO SEE IF
MAYBE THERE WAS AN INCREASE IN
CRIB BINDING OR CRIB ACTIVITY OF
THIS PROMOTOR AND IT TURNS OUT
IT DOESN'T BIND THIS PROMOTOR
IN-VIVO.
CONTRARY TO THE IN-VITRO
STUDIES.
BUT WE DECIDED TO LOOK AT
CHROMATIN MODIFICATIONS AND WE
THOUGHT MAYBE LITHIUM MIGHT BE
AFFECTING CHROMATIN STRUCTURE
AND THEREBY ALLOWING MORE
PERMISSIVE TRANSCRIPTION.
SO, WE LOOKED AT ACET LETTED
HISTONE H3 WHICH IT IF IT IS
ACETYLATED IT WILL MAKE THE
CHROMATIN MORE PERMISSIBLE TO
TRANSCRIPTION.
IT WILL OPEN IT UP FROM THE
HISTONES.
SO YOU CAN SEE WHEN WE LOOKED AT
MUTANT ANIMALS, GIVEN LITHIUM,
WE SAW INCREASE IN ACETYLATED H3
AT THE CCK PROMOTOR COMPARED TO
THE WATER CONTROLS.
AND WE SAW INCREASE WITH
WILDTYPE MICE BUT IT WASN'T
SIGNIFICANT.
AND WHEN WE LOOKED AT HISTONE
H4, WE SAW A MORE DRAMATIC
PHENOTYPE WHERE THERE SEEMS TO
BE A SELECTIVE INCREASE IN
ACETYLATION OF HISTONE H4 AT THE
CCK PROMOTOR IN THE MUTANT MICE
GIVEN LITHIUM.
AND SO THIS SUGGESTS THAT
LITHIUM TREATMENT IS ALTERING
THE CHROMATIN STRUCTURE AND
ALLOWING MORE PERMISSIVE
TRANSCRIPTION OF THE CCT GENE.
SO WE WONDERED IF WE GAVE THE
MICE VAL CROWIC ACID, ANOTHER
MOOD STABILIZING DRUG KNOWN TO
INHIBIT THE ACTIVITY OF HISTONE
DEACETYLASES, SO THE PROTEINS
THAT NORMALLY TAKE AWAY HISTONE
ACETYLATION, WE WONDERED IF THIS
WOULD ACT LIKE LITHIUM AND
REVERSE THEIR PHENOTYPE.
AS WELL, BECAUSE THIS DOES
SEVERAL THINGS, NOT JUST AN
INHIBITOR, IT AFFECTS A LOT OF
PROTEINS.
SO WE WENT TO A MORE SPECIFIC
HDAC INHIBITOR AND WE AGAIN
WANTED TO FINISH IT WOULD CHANGE
THE BEHAVIOR OF THE CLOCK MUTANT
MICE.
AND WHAT WE FOUND WAS, BOTH
RESTORED THEIR ANXIETY-RELATED
PHENOTYPES TO THAT OF WILDTYPE
MICE AND BOTH DRUGS HAD NO
AFFECT ON WILDTYPE MICE IN THE
OPEN FIELD OR THE TIME SPENT IN
THE LIGHT AND DARK LIGHT.
SA HA DID HAVE A LITTLE BIT OF
ANTIANXIETY AFFECT WHEN YOU LOOK
AT PERCENT TIME IN THE LIGHT
HERE AND THAT IS COMMON.
SOMETIMES WITH LITHIUM OR VAL
PRO.
YOU WILL SEE ANTIANXIETY AFFECT.
IN THIS CASE IT'S GOT A LITTLE
ANTIANXIETY AFFECT IN WILDTYPE.
WHEN WE LOOK AT
DEPRESSION-RELATED BEHAVIORS, WE
SAW THAT THIS IS IN THE POOR
SWIM TEST.
VAL PRO AND SA HA WERE ABLE TO
BEGIN TO REVERSE THEIR
DEPRESSION-RELATED BEHAVIORS
MAKING THEM MORE LIKE WILDTYPE
MICE.
SO THIS WOULD SUBJECT THAT HDAC
INHIBITION COULD BE A NOVEL
THERAPEUTIC TARGET FOR THE
TREATMENT OF BIPOLAR DISORDER.
SO, JUST TO WRAP UP, BASICALLY,
I HOPE YOU APPRECIATE THAT
CIRCADIAN RHYTHM DISRUPTION IS
POTENTIAL EVOLOVED IN
DEVELOPMENT OF PSYCHIATRIC
DISEASES AND IN PARTICULAR,
MUTATION NO, SIR CIRCADIAN
GENES --
MEW DAYSES IN CIRCADIAN GENES
AND HAVE IMPACT ON MOOD AND
REWARD REGIONS OF THE BRAIN.
THIS IS AN ATTEMPT TO MAKE THIS
INTO A DIAGRAM.
WHERE BASICALLY YOU HAVE THE
LIGHT DARK CYCLE AFFECT THE THE
SBN TO REGULATE INDIRECT
PROJECTIONS IN HORMONE
REGULATION AND CIRCADIAN
PATTERNS AS WELL AS SLEEP/WAKE
REGULATIONS WHICH FEED INTO
THESE REWARD AND MOOD-RELATED
CIRCUITS IN THE BRAIN WHICH ARE
ALL CONNECTED TO EACH OTHER IN
SYNCHRONIZING TO EACH OTHER AS
ANIMALS ARE EXPLORING DIFFERENT
TASKS OR INVOLVED IN DIFFERENT
MOOD-RELATED OR ANXIETY RELATED
PARADIGMS.
THERE ARE CIRCADIAN GENE
EXPRESSION GOING ON IN ALL OF
THESE DIFFERENT REGIONS AND
CLOCKS GOING IN THESE DIFFERENT
REGIONS.
SO THEY MAY BECOME
DESYNCHRONIZED BY EACH OTHER BY
STRESS, DRUGS OF USE, ET CETERA.
AND LIGHTSIUM AND VAL PROIC ACID
AND OTHER HDAC HIBITOR MIGHT BE
ABLE TO COME IN AND REGULATE
SOME OF THESE CIRCUITS CREATING
BETTER SINKNY, MAYBE CHANGE SOME
OF NEURONAL FIRING RATE AND ALL
OF THIS NEEDS TO BE IN LINE TO
CONTROL ALL OF THESE DIFFERENT
FACETS OF MOOD ACTIVITY, REWARD,
MOTIVATION, ET CETERA.
SO IT'S VERY COMPLICATED.
THIS IS A LOT OF FACTORS LEADING
INTO THIS BUT HOPEFULLY WE CAN
START TO DISSECT WHAT THESE
DIFFERENT REGIONS ARE OR HOW
THEY ARE COMMUNICATING WITH EACH
OTHER.
HOW THEY ARE INVOLVED IN THESE
DIFFERENT FACETS OF MANIC-LIKE
AND DEPRESSION-LIKE BEHAVIOR AND
HOW THESE OTHER ENVIRONMENTAL
STIMULI ARE INVOLVED IN
MODULATING THIS.
SO, I'LL STOP THERE AND THANK
THE CURRENT MEMBERS OF OUR LAB
AND SOME PAST MEMBERS OF MY LAB
THAT WORKED ON THIS.
VERY GREAT GROUP OF PEOPLE TO
WORK WITH.
AND THEY REALLY HAVE PRODUCED
SOME TREMENDOUS WORK.
WE HAVE LOTS OF COLLABORATORS.
ENGI MENTIONED THEM ALONG THE
WAY, WHO REALLY HELP, ESPECIALLY
WITH THE ELECTROPHYSIOLOGY,
SINCE WE ARE MOLECULAR
BIOLOGISTS AND BEHAVIORISTS.
SOME OF OUR COLLABORATORS YOU
SEE AT SOUTHWESTERN AND OF
COURSE OUR FUNDING, PARTICULARLY
FROM THE NIH, WHICH HAS BEEN
VERY GENEROUS TO US, TO FUND
THESE STUDIES AND THIS IS DALLAS
HERE AND OUR NEW HOME IN
PITTSBURGH.
SO THANK YOU.
[APPLAUSE]
>> [OFF MIC]
>> SO IT'S A TOM NANT NEGATIVE.
WHEN THEY ARE IN A LIGHT DARK
CIRCLE THEY SHOW SOME CIRCADIAN
RHYTHMS BUT THEY ARE VERY MESSY.
THEY DON'T EN TRAIN VERY WELL TO
THE LIGHT.
IF YOU YOU WERE TO PUT THEM IN
CONSTANT DARKNESS THEY GO INTO
ARRHYTHMIC BEHAVIOR PRETTY
QUICKLY.
THEY STILL SHOWED SOME RHYTHM
BUT THEY ARE PRETTY MESSY.
WE DID TRY TO GIVE THEM LITHIUM
TO SEE IF THAT WOULD EFFECT OR
REEN TRAIN THEIR CIRCADIAN
PERIOD IN THE DARK PHASE AND IT
DIDN'T SEEM TO IN THE 10 DAYS WE
GAVE IT FOR MOST OF OUR
EXPERIMENTS, AND MIGHT NEED TO
GO LONGER IN ORDER TO SEE THAT.
BUT WE HAVEN'T DONE THAT WITH
THE HDAC INHIBITORS YET.
SO I'M NOT SURE ABOUT THAT.
>> [OFF MIC]
>> SO THERE ARE SEVERAL
POSSIBILITIES WE HAVE COME UP
WITH FOR WHAT IS GOING O ONE IS
THAT THERE MIGHT BE DIFFERENT
PATTERNS OF BURSTING VERSUS
CHRONIC FIRING.
SO, THE BURST FIRING IS VERY
IMPORTANT FOR REWARD-RELATED
EVENTS, ESPECIALLY UNEXPECTED
REWARD AND THESE TYPES OF
THINGS.
WE HAVE A COLLABORATOR AT MOUNT
SINAI WHO ALSO WORKS WITH US WHO
THINKS THIS MIGHT BE THE CASE.
HE THINKS THAT THERE MIGHT BE
SOME CHANGE IN THE TONIC VERSUS
PHASIC FIRING THAT IS IMPORTANT
IN THE DEVELOPMENT OF THE
DEPRESSION VERSUS MANIC-LIKE
PHENOTYPE.
ANOTHER POSSIBILITY IS THAT
THERE ARE DIFFERENT POPULATIONS
OF DOPAMINE NEURONS WHICH ARE
BEING SELECTIVELY ACTIVATED.
SO THERE ARE NEURONS --
NOT ALL THE DOPAMINE NEURONS
PROJECT THE DOPAMINE SUCCUMB
BENS.
THEY ALSO PROJECT TO THE
PREFRONTAL CORTEX AND AMYGDALA.
IT IS POSSIBLE WE ARE ACTIVATING
A SELECT POPULATION AND THAT'S A
EXPERIMENT WE ARE ABOUT TO DO
USING OPT GINETTICS TO DO
PROJECTION-BASED TARGETING WHERE
WE CAN PUT THE CHANNEL IN THE
VTA AND PUT THE LIGHT IN THE
PREFRONTAL CORTEX OR AMYGDALA OR
WHEREVER, AND SEE IF WE
SPECIFICALLY STIMULATE ONE OF
THOSE POPULATIONS, WHAT KIND OF
BEHAVIOR ARE WE GOING TO GET.
AND THEN THERE IS SOME OTHER
POSSIBILITIES BUT THOSE ARE THE
MOST MAIN TWO WE ARE FOCUSING ON
RIGHT NOW
[OFF MIC]
>> SO IT DOES SEEM TO BE PRETTY
NORMAL IN THE CLOCK MUTANT MICE.
WE HAVEN'T LOOKED TO SEE IF HDAC
ACTIVITY IS NORMAL, ALTHOUGH WE
DIDN'T SEE VERY MANY --
DIDN'T SEE ANY GLOBAL CHANGES IN
CHROMATIN.
WE JUST DID SORT OF WESTERN
BLOTS FOR ACETYLATED H3 OR H4.
DIDN'T SEE ANY GLOBAL CHANGES.
BUT WE HASN'T LOOKED AT WHICH
SPECIFIC HDACs TO SEE IF THERE
IS CHANGES IN ACTIVITY.
>> I WISH WE KNEW.
I DON'T KNOW.
I DON'T KNOW HOW IT IS DOING IT,
HONESTLY.
WE --
WE CAN COME UP WITH ALL
DIFFERENT THEORIES AND IT MAY BE
THROUGH GFK3 BETA AT SOME LEVEL
BUT WE DON'T KNOW.
WE DON'T KNOW HOW IT IS
AFFECTING --
AND WE DON'T FINISH IT'S THROUGH
AN INCREASE IN ACETYLATION OR A
DECREASE IN HDAC FUNCTION.
WE DON'T KNOW WHICH WAY IT IS
AFFECTING IT.
SO, IT COULD BE EITHER ONE.
>> [OFF MIC]
>> YES, SO SEVERAL OF THE GENES
DO CYCLE BUT CLOCK ACTUALLY
AFFECTS THE NUMBER OF GENES THAT
DON'T CYCLE.
SO IT EFFECTS BOTH.
A NUMBER OF THOSE GENES --
CCK HAS A VERY PROMINENT
CIRCADIAN CYCLE.
IT DEFINITELY EFFECTS GENES THAT
DON'T CYCLE.
>> [OFF MIC]
>> RIGHT.
SO WE HAVE LOOKED AT THE PERIOD
GENE MUTANTS AND SO WE HAVE
LOOKED AT PER 1, PER 2 AND PER 3
AND THE DOUBLE COMBINATIONS.
AND ESSENTIALLY, THEY DON'T HAVE
THE SAME PHENOTYPE.
SO THEY DON'T HAVE AN OVERALL
MANIC-LIKE PHENOTYPE.
THEY DO HAVE --
SO THE SINGLE GENE KNOCK OUTS
DONE SEEM TO HAVE MUCH OF A
DIFFERENCE IN PHENOTYPES IN
TERMS OF ANXIETY OR
DEPRESSION-RELATED BEHAVIOR OR
REWARD-RELATED BEHAVIOR.
BUT THE DOUBLE KNOCK OUTS HAVE
AN INCREASE IN ANXIETY.
SO THE OPPOSITE OF WHAT WE SEE
WITH THE CLOCK MUTANT MICE AND
BUT THEY HAVE A DECREASE IN
DEPRESSION-RELATED BEHAVIOR.
SO THEY ARE KIND OF WEIRD.
WE DON'T KNOW WHAT TO MAKE EVER
THAT.
BUT THEY ARE NOT HYPERACTIVE.
AND THEY DON'T HAVE ALL OF THE
SAME FEATURES THAT THE CLOCK
MUTANT MICE HAVE.
WE HAVE TESTED BMAL KNOCKOUT
MICE WHICH ARE HARD TO WORK WITH
BECAUSE THEY ARE VERY SICK.
BUT THEY, FROM WHAT WE WERE ABLE
TO DO WITH THEM, THEY DID HAVE
HYPERACTIVITY AND THEY DID HAVE
SOME OF THE SAME FEATURES OF THE
CLOCK MUTANTS.
SO WE THINK IT IS BMAL1 AND
CLOCK TOGETHER.
BUT WHETHER IT HAS BEEN THROUGH
THE PERIOD GENES AND CRYPTO
CHROME GENES AND ALL THAT
AFFECTING IT, WE DON'T THINK SO.
IT'S PROBABLY DOING SOMETHING
ELSE ON THESE OTHER GENES MAYBE
CCK, TH, SOME OF THESE OTHER
TARGETS THAT ARE MORE RELEVANT
THAN THE PERIOD AND CRYPTO
CHROME.
NOW, WHETHER OR NOT THE
CIRCADIAN DISRUPTION IS
IMPORTANT FOR THOSE, WE FELT
LIKE MAYBE DOING THIS INITIAL
KNOCKDOWN IN THE VTA WAS GOING
TO GIVE US THAT ANSWER, BUT
BECAUSE WE FIGURED WE WOULD
KNOCK DOWN CLOCK IN THE VTA AND
HAVE NORMAL CIRCADIAN RHYTHMS
BUT WHEN YOU KNOCK DOWN CLOCK IN
THE VTA, YOU GET CIRCADIAN
DISRUPTIONS IN LOCAL MOTOR
ACTIVITY.
WE STILL CAN'T SAY WHETHER OR
NOT THE CIRCADIAN RHYTHM
DISRUPTION IS IMPORTANT OR IF
CLOCK IS DOING SOMETHING THAT IS
INDEPENDENT OF IT'S ROLE IN THE
CIRCADIAN RHYTHM.
IT'S SOMETHING WE ARE INTERESTED
IN TRYING TO SEE.
>> [OFF MIC]
>> I THINK THERE IS TWO REASONS.
FIRST OF ALL, WHEN WE KNOW FROM
GENETIC STUDIES THAT MUTATIONS
IN THE CLOCK GENE ARE ASSOCIATED
WITH THESE DISORDERS.
SO IT COULD BE THAT IF YOU WERE
TO TARGET CLOCK THERAPEUTICALLY
DIRECTLY, OR ONE OF ITS TARGETS
THAT THIS MIGHT BE AN EFFECTIVE
TREATMENT.
WE ALSO KNOW THAT CIRCADIAN
RHYTHM DISRUPTIONS, SO
ENVIRONMENTAL DESCRIPTIONS SEEM
TO HAVE A HUGE IMPACT ON THE
OUTCOME OF BIPOLAR PATIENTS.
SO I THINK IT'S SORT OF LOOKING
AT IT BOTH WAYS.
HOW THE MUTATIONS IN THESE GENES
MIGHT LEAD TO A VULNERABILITY
FOR THESE KINDS OF DISEASES BUT
THEN ALSO HOW CIRCADIAN RHYTHM
DISRUPTION IN GENERAL MIGHT
IMPACT A DISEASE THAT SOMEBODY
ALREADY HAS AND MAKE IT WORSE.
SO, I THINK THERE IS BOTH.
AND LIKE I WAS SAYING, WE DON'T
KNOW FOR SURE.
IF YOU HAVE A MUTATION IN THE
CLOCK GENE, YOU'RE GOING TO HAVE
BOTH MOOD RELATED PROBLEMS AND
CIRCADIAN RELATED PROBLEMS BUT
MAYBE THE TWO AREN'T NECESSARILY
CONNECTED OR MAYBE OR IT COULD
BE THE MUTATION IN CLOCK IS
LEADING TO A CIRCADIAN RHYTHM
DISRUPTION LEADING TO DISORDER
AND WE JUST --
IT'S SUCH AN EARLY STAGE AND WE
DON'T KNOW WHICH IS TRUE.
OR IT COULD BE A LITTLE BIT OF
BOTH.
SO WE ARE SORT IT OF LOOKING AT
IT IN BOTH WAYS.
>> [OFF MIC]
>> WE EVAPORATE CONSIDERED THAT.
THAT WOULD BE INTERESTING TO DO.
I DON'T THINK OUR LAB IS
EQUIPPED TO DO THAT KIND OF
THING BUT THAT WOULD BE
INTERESTING.
WE HAVEN'T THOUGHT ABOUT DOING
ANYTHING LIKE THAT.
ANYTHING ELSE?
>> [OFF MIC]
>> NO.
WE DO REALLY WANT TO GET INTO
LOOKING AT SEROTONIN MORE
DIRECTLY.
SEROTONIN IS ACTUALLY KEY TO
SETTING CIRCADIAN RHYTHMS AND
OBVIOUSLY IS INVOLVED IN MOOD
REGULATION.
SO I GREATLY SUSPECT THE
SEROTONIN SYSTEM IS VERY, VERY
RELEVANT TO THIS MODULATION OF
MOOD AND IF WE WERE TO ACTIVATE
THAT CIRCUIT, WE PROBABLY WOULD
GET CHANGES IN MOOD-RELATED
BEHAVIORS.
SO WE JUST HAVEN'T DONE THAT
YET.
THE DORSAL RAV RAFFAH IS PRETTY
HARD TO WORK ON IN MICE BUT IT'S
SOMETHING WE DEFINITELY WOULD
LIKE TO DO.
THANK YOU.
[APPLAUSE]