Download presentation
Presentation is loading. Please wait.
Published byRudolf Ray Modified over 9 years ago
1
CHRONOBIOLOGICAL APPLICATIONS OF CIRCADIAN CLOCK JET LAG -Resetting the clock by exposure to light at either dusk or dawn. -East to West: Later dusk, delay of clock. -West to East: Earlier dawn, advance of clock. -Resetting by drugs -Protein synthesis inhibitors: Causes phase-shifts (DRCs). -Protein phosphorylation and dephos: Causes period changes. SHIFT WORK; ACCIDENTS AND PERFORMANCE AT NIGHT -Many shift workers do not shift their biological clock. But alertness and task performance follows phase of the unshifted rhythm. -Single vehicle truck and car accidents and fatalities. Three Mile Island, Chernobyl, Exxon Valdez. CHRONOTHERAPY -DSPI: Delayed Sleep Phase Insomnia. Failure of advance phase shifts. -ASPI: Advance Sleep Phase Insomnia. Failure of delay phase shifts -SAD: Seasonal Affective Disorder. Day length. -Timing of drug administration; chronopharmacology; LD 50s
2
TYPE O (strong) & TYPE 1 (weak) PRCs in Gonyaulax with and without CREATINE
3
DRUG PRC for CYCLOHEXIMIDE, a PROTEIN SYNTHESIS INHIBITOR
4
EFFECTS OF KINASE INHIBITORS ON PERIOD (TAU)
5
EFFECT OF PROTEIN PHOSPHATASE INHIBITORS ON PERIOD
6
EFFECT OF CREATINE (FROM DIFFERENT SOURCES) ON PERIOD
7
CHRONOBIOLOGICAL APPLICATIONS OF CIRCADIAN CLOCK JET LAG -Resetting the clock by exposure to light at either dusk or dawn. -East to West: Later dusk, delay of clock. -West to East: Earlier dawn, advance of clock. -Resetting by drugs -Protein synthesis inhibitors: Causes phase-shifts (DRCs). -Protein phosphorylation and dephos: Causes period changes. SHIFT WORK; ACCIDENTS AND PERFORMANCE AT NIGHT -Many shift workers do not shift their biological clock. But alertness and task performance follows phase of the unshifted rhythm. -Single vehicle truck and car accidents and fatalities. Three Mile Island, Chernobyl, Exxon Valdez. CHRONOTHERAPY -DSPI: Delayed Sleep Phase Insomnia. Failure of advance phase shifts. -SAD: Seasonal Affective Disorder. Day length. -Drug administration; chronopharmacology; LD 50s
8
TIMES OF SINGLE VEHICLE TRUCK ACCIDENTS
9
MYOCARDIAL INFARCTIONS AT DIFFERENT TIMES OF DAY
10
CHRONOBIOLOGICAL APPLICATIONS OF CIRCADIAN CLOCK JET LAG -Resetting the clock by exposure to light at either dusk or dawn. -East to West: Later dusk, delay of clock. -West to East: Earlier dawn, advance of clock. -Resetting by drugs -Protein synthesis inhibitors: Causes phase-shifts (DRCs). -Protein phosphorylation and dephos: Causes period changes. SHIFT WORK; ACCIDENTS AND PERFORMANCE AT NIGHT -Many shift workers do not shift their biological clock. But alertness and task performance follows phase of the unshifted rhythm. -Single vehicle truck and car accidents and fatalities. Three Mile Island, Chernobyl, Exxon Valdez. CHRONOTHERAPY -DSPI: Delayed Sleep Phase Insomnia. Failure of advance phase shifts. -SAD: Seasonal Affective Disorder. Day length. -Drug administration; chronopharmacology; LD 50s
11
DELAYED SLEEP PHASE INSOMMNIA THERAPY Deficiency in advance phase shifts Treatment: Impose repeated delays until patient is back in phase.
12
IS THE CIRCADIAN CLOCK NECESSARY ? DOES THE CLOCK CONFER SELECTIVE ADVANTAGE? MEASURE LIFESPAN IN ANIMALS SUBJECTED TO NON-24 hr CYCLES RESONANCE EXPERIMENTS IN CYANOBACTERIA USING PERIOD MUTANTS
13
SURVIVIAL CURVES FOR FLIES IN LIGHT/DARK CYCLES WITH PERIODS OF 20, 24 AND 28 HOURS
14
FIVE HOUR LD PHASE SHIFTS EACH CYCLE
15
MUTANTS V.S. WILD TYPE IN DIFFERENT LD CYCLES
16
MUTANT TAU-28 V.S. WILD TYPE
17
SOME FUNCTIONS OF THE CIRCADIAN CLOCK TIME ACTIVITIES: CERTAIN TIMES OF DAY/NIGHT Insect eclosion acrophase is at time of daily temperature minimum. The internal bee clock; Visitations timed to time of flower openings Cyanobacteria, photosynthesis by day, nitrogen fixation by night. CELESTIAL NAVIGATION -Animal migration (birds, butterflies, arthropods, fish, reptiles); knowledge of time of day required. PHOTOPERIODISM: MEASURE DURATION OF DAY AND NIGHT -Plant rhythms: seasonal flowering, spring, summer or fall. -Animal seasonal reproduction; hamster only once per year.
18
DROSOPHILA ENTRAINMENT TO FULL LD CYCLES PITTENDRIGH
19
BEAN (top) and CANAVALIA CIRCADIAN LEAF MOVEMENTS
20
TEMPORAL SEPARATION OF CELL BIOCHEMICAL ACTIVITIES IN CYANOBACTERIA ( OXYGEN, NITROGENASE ETC) MITSUI ET AL 1986
21
OXYGEN PRODUCTION (TOP) & NITROGENASE (BOTTOM) IN CYANOBACTERIA IN LD (LEFT) &LL (RIGHT ) Stal & Krumbeing, 1987
22
SOME FUNCTIONS OF THE CIRCADIAN CLOCK TIME ACTIVITIES: CERTAIN TIMES OF DAY/NIGHT Insect eclosion acrophase is at time of daily temperature minimum. The internal bee clock; Visitations timed to time of flower openings Cyanobacteria, photosynthesis by day, nitrogen fixation by night. CELESTIAL NAVIGATION -Animal migration (birds, butterflies, arthropods, fish, reptiles); knowledge of time of day required. PHOTOPERIODISM: MEASURE DURATION OF DAY AND NIGHT -Plant rhythms: seasonal flowering, spring, summer or fall. -Animal seasonal reproduction; hamster only once per year.
26
DIRECTION OF STARLING MIGRATORY ACTIVITY Kramer,1950 a) clear sky b)overcast c),d) direction of incident light deflected by mirrors
27
DIRECTION OF DEPARTURE IN PIGEONS ALTERED AFTER EXPOSURE TO LD CYCLE ALTERED BY 6 hr Schmidt-Koenig,1961
28
SHIFTING THE DIRECTIONAL RESPONSE OF PIGEONS
29
SOME FUNCTIONS OF THE CIRCADIAN CLOCK TIME ACTIVITIES: CERTAIN TIMES OF DAY/NIGHT Insect eclosion acrophase is at time of daily temperature minimum. The internal bee clock; Visitations timed to time of flower openings Cyanobacteria, photosynthesis by day, nitrogen fixation by night. CELESTIAL NAVIGATION -Animal migration (birds, butterflies, arthropods, fish, reptiles); knowledge of time of day required. PHOTOPERIODISM: MEASURE DURATION OF DAY AND NIGHT -Plant rhythms: seasonal flowering, spring, summer or fall. -Animal seasonal reproduction; hamster only once per year.
30
DAY LENGTH AT DIFFERENT LATITUDES & SEASONS
31
CIRCANNUAL RHYTHMS IN SQUIRRELS & GONYAULAX
32
ANNUAL RHYTHM OF HUMAN REPRODUCTION Roenneberg & Aschoff,1990
33
PHOTOPERIODISM DISCOVERY: Garner & Allard, 1920 TOBACCO FLOWERING ONLY IN FALL WITH SHORT DAYS OTHER PLANTS SHOWN TO FLOWER WITH LONG DAYS. STILL OTHERS DAY LENGTH NEUTRAL TERMINOLOGY CORRECTED: Hamner & Bonner, 1938 LENGTH OF THE NIGHT, NOT THE DAY, IS CRITICAL LIGHT INTERRUPTIONS OF NIGHT BLOCK RESPONSE, DARK INTERRUPTIONS OF DAY DO NOT BLOCK INCORRECT TERMINOLOGY STILL IN USE:
34
HAMSTER TESTIS WEIGHT IN DIFFERENT FULL PHOTOPERIODS Elliott, 1976
35
PHOTOPERIODIC INDUCTION OF CYSTS IN GONYAULAX
36
SOY BEAN (SHORT DAY PLANT) 0.5 hr LIGHT INTERRUPTION OF LONG DARK PERIOD WARING, 1954
37
H. NIGER (LONG-DAY PLANT) 2 hr LIGHT INTERRUPTION OF LONG DARK PERIOD
38
SOYBEAN FLOWERING IN DIFFERENT LD CYCLES
39
MODELS FOR PHOTOPERIODISM HOUR GLASS: Substance X builds up during dark Explains night interruption Does not explain oscillation of long dark periods. ENDOGENOUS OSCILLATION External Coincidence model: Large delays & advances Internal Coincidence model: Light cycle entrains. Response is caused by interaction between two internal oscillators, pacemaker and slave.
40
EXTERNAL COINCIDENCE: POSTULATED PHOTOPERIODIC EFFECTS ON AN ORGANISM WITH A CIRCADIAN TAU OF 24.5 hr
41
ENTRAINMENT TAU OF HAMSTER ACTIVITY RHYTHM DEPENDS ON PERIOD OF SINGLE PULSE T CYCLE AND PULSE IS POSITIONED DIFFERENTLY Elliott 1976 Tau for hamster is very close to 24 h
42
TESTICULAR RESPONSES TO ONE PULSE T CYCLE LENGTH
43
DROSOPHILA ENTRAINMENT TO FULL LD CYCLES PITTENDRIGH
44
BISTABILITY IN 2-PULSE SKELETON PHOTOCYCLES (Pittendrigh;Drosophila)
45
PHASE ANGLES WITH DIFFERENT TWO PULSE SKELETONS Pittendrigh
46
BISTABILITY IN HAMSTER ENTRAINMENT SKELETON PHOTOPERIOD 13.5:0.25:10:0.25 hrs ANIMAL C15 ACTIVE INSHORT NIGHT TESTES MAINTAINED; ANIMAL C16 ACTIVE IN LONG NIGHT; TESTES REGRESSED
47
SKELETON PHOTOPERIOD PHASING GIVES DIFFERENT RESPONSES
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.