Lecture 74 Flashcards
Major role in regulation of sleep and wakefullness
Melatonin
Melatonin is produced by the _______ located behind the 3rd ventricle
Pineal gland
Melatonin is synthesized from _______ with serotonin as an intermediate
Tryptophan
_______ kind of light suppresses melatonin?
Blue light
Blue light is photic information from the retina transmitted to hypothalamus and SNS via the _______ then to pineal gland
Supra-chiasmatic nucleus
Secretion of melatonin is regulated by _______?
Light
Melatonin is stimulated by?
Darkness
Melatonin is inhibited by?
Light
In the darkness retinal photoreceptors release norepinephrine, which activates _______ in the pineal gland
Beta adrenergic receptors
In the darkness _______ is converted to melatonin
Serotonin
Retinal photoreceptor cells become _______ in the light which inhibits release of norepinephrine
Hyperpolarized
Can blind animals still have light-induced suppression of melatonin?
YES
Circadian rhythm of melatonin secretion is controlled by _______ in the supra-chiasmatic nucleus
endogenous pacemaker
T/F: environmental lighting does not alter timing of circadian rhythm
F
Day light cycles can modify?
timing of circadian rhythm
brief _______ of light suppress melatonin
pulses
When is the peak secretion of melatonin?
around 2-4 am
Shifts in melatonin secretion after flights across time zones and night shift works can?
After melatonin and circadian rhythm
Melatonin increases until _______ age then it declines?
1-3 yrs old
Melatonin activates _______ and _______ receptors
MT1, MT2
sleep, circadian rhythm, mood, sexual maturation, reproduction, anti-inflammatory, cancer and aging. _______ regulates/ affects these?
Actions of melatonin
Melatonin affects speed of falling asleep and duration?
quality of sleep
Abnormal circadian rhythms are implicated in
mood disorders
Bright-light therapy can _______ depression and help seasonal affective disorder
decrease
Hours of darkness/season linked to
reproductive activity
In mares and their estrus cycle melatonin _______ during long winter nights
increases