Role of melatonin

How does melatonin play role in day-night cycle? The current presentation gives the best idea on it.

1. Role of melatonin in Circadian
Rhythm
Dr. SurjyaKumar Saikia
Department of Zoology
Visva-Bharati

2. •Role of master clock and its associates
•Mechanism of melatoninsecretion
•Melatoninreceptors
•Different physiological role ofmelatonin
•Effectof low/highmelatoninlevels
What we will learn?

3. AroneLerner
1958
Melatonin
N-acetyl-5 methoxytryptamine.

4. Melatoninisanaturallyoccurringcompoundfoundinall
livingcreaturesfromalgaetohumans
Itisknownas“Hormoneofdarkness”.Itissecretedin
darknessinbothday-active(diurnal)andnight-active
(nocturnal).
Itisnaturallysynthesizedfromtheaminoacid
tryptophan. Melatoninproducedinthepinealgland
actsasanendocrinehormonesinceitisreleasedinto
theblood.

5. Duringtheday.
At night
THE MASTER CLOCK
Invertebrateanimals, including humans, the master
clock is a group of about 20,000nerve
cells(neurons) that form a structure called the
suprachiasmaticnucleus, or SCN
It fires electrical signals at intervals throughout the day.
During an organism’s time of peak activity, these signals
are being fired off very quickly. When the organism slows
and sleeps, the signals are much less frequent.
RoleoftheSCNintheSleep-Wakecycle

6. Inhigheranimals,melatonin
isproducedbypinealocytesin
the pineal gland (located in
the brain) and also by the
retina , lens andGI tract
Source: Tarrant-Trilogy Integrated Resources

7. Source: StandfordUniversity
From analesranf
shopify.com

8. Melatonin works to keep circadian rhythm in sync.
Morning light also signals the brain to release cortisol, which is our awake hormone.
Children tend to have the highest levels of melatonin. As we get older melatonin levels drop. This is related to older
people going to bed and waking up earlier than they did as a kid. As you get older, melatonin levels decrease causing
sleep to decrease.

9. MULTIPLE FUNCTIONS OF MELATONIN

10. Too Much or Too Little Melatonin
•Too Much
•Seasonal Affective Disorder (SAD)
•Found most often during the long nights of winter
•This disorder results in profound depression, oversleeping, weight gain, tiredness, and
sadness.
•Not Enough
•Insomnia
•Difficulty falling asleep
•Wake up often and have difficulty falling asleep
•Waking up early and waking up tired

11. Too Much/Little Melatonin
Seasonalaffectivedisorderoccursinclimates
wherethereislesssunlightatcertaintimesof
theyear.
Symptoms includefatigue,depression,
hopelessnessandsocialwithdrawal.
Insomniaisasleepdisorderinwhichyouhave
troublefallingand/orstayingasleep

12. Melatonin is Replaced By….
•Melatonin can be made in the laboratory
for people to take in pill form.
•These pills are absorbed directly into the
body and will help someone fix their
internal “clock” for sleep.
•Melatonin Supplements

13. Blue light like from monitor screens suppress
almost completely melatoninsecretion
NB: Blue light from television, PC and laptop screens, smart phones are of the sourcesof the worst
blue lights one can be exposed to and by leaving a television set or laptop screen on during the
night will suppress melatonin productionsignificantly.
Theblue lightthat's emitted from these screens can delay the release of sleep-inducingmelatonin, increase
alertness, and reset the body's internal clock (or circadian rhythm) to a later schedule.

14. Natural way to increase melatonin
•Early to bed and early torise
•Food: Oats, sweet corn, rice,
barley, tomatoes andbananas
•Vitamin B3, B6 (dried apricots,
barley, whole wheat, tuna and
turkey, rice, bananas, lentils,
shrimp andcarrots)

15. Foods containing
melatonin orinduce
the natural
production of
melatonin Improve
your nights sleep

16. Deep sleep in the dark is the cheapest source
of Melatonin