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Page 1: Chap 49-2 Melatonin and sleep/wake cycles B9902021 周予婷 B9902033 侯如盈

Chap 49-2

Melatonin and sleep/wake cycles

B9902021 周予婷B9902033 侯如盈

Page 2: Chap 49-2 Melatonin and sleep/wake cycles B9902021 周予婷 B9902033 侯如盈

Melatonin• A hormone secreted by the pineal gland

– contains light-sensitive cells or has nervous connection from the eyes

– converts serotonin into melatonin

• The Melatonin/Serotonin cycle

tryptophanmelatonin

serotoninneurotransmitter of the sleeping-producing centersneurotransmitter of the sleeping-producing centers

high in milkhigh in milk

Page 3: Chap 49-2 Melatonin and sleep/wake cycles B9902021 周予婷 B9902033 侯如盈

• a vital part of many biochemical systems – including sleep and learning

• free radical scavenging in all cells– a potent antioxidant with anti-aging and anti-cancer

properties

• helps to protect embryonic fetuses• mediates many hormone functions• assists in maintaining immune system health

and virus protection

Functions of melatonin

Page 4: Chap 49-2 Melatonin and sleep/wake cycles B9902021 周予婷 B9902033 侯如盈

The regulation of the melatonin secretion

SCN (suprachiasmatic nucleus)

melatonin

project the information about illumination

ganglion cells

the pineal gland

interprets the information on the lengths of the day and night

secretes

feedback(unknown): decrease the activity of SCN

Page 5: Chap 49-2 Melatonin and sleep/wake cycles B9902021 周予婷 B9902033 侯如盈

Fig. The biochemical mediation system for serotonin transformation to melatonin in the pinealocytes showing the signal transduction pathways from the retina to the cell and the cell receptor, through cyclic AMP and NAT to the transformation process, Reiter (1994).

PVN:室旁核paraventricular nucleus

SCG:上頸神經節superior cervical ganglia

NE:正腎上腺素Norepinephrine

NAT: N-乙醯轉移酶N-acetyltransferase

N- Acetylserotonin O-methyltransferase

松果體細胞

Page 6: Chap 49-2 Melatonin and sleep/wake cycles B9902021 周予婷 B9902033 侯如盈

Potential medical indications

• Cancer • Immunology• Menstrual cycle - fertility• Puberty onset • Learning and memory • Treatment of circadian rhythm disorders • Mood disorders

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Insomnia• Types of insomnia– jet lag– the chronic circadian rhythm disorders

• Treatment– Melatonin and melatonin agonists relatively mild side-effect without altering the sleep pattern– Antidepressants – Antihistamines

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Seasonal affective disorder (SAD)

• Mood disorder • the normal biorhythm is disturbed during a

season, especially autumn-winter• Symptoms– oversleep / over eat / difficulty concentrating/

depression

• Treatment – light therapy and supplementation of melatonin.

Page 9: Chap 49-2 Melatonin and sleep/wake cycles B9902021 周予婷 B9902033 侯如盈

The 24-Hour Cycle of Melatonin Production

EEG-α wave ↑

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一生中褪黑素的變化

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參考資料• Campbell• Wiki

– Melatonin/Circadian rhythm/N-acetyltransferase /SAD/Insomnia

• 內分泌精義• 臨床睡眠檢查學• Dr Neil Cherry, 2000: EMR Reduces Melatonin in Animals

and People– (http://www.feb.se/EMFguru/Research/emf-emr/EMR-

Reduces-Melatonin.htm)


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