Melatonin

Question 1

What is the Photoregulated enzyme for the ACETYLATED step in Melatonin Synthesis

Answer 1

Seratonin-N-acetyl Transferase

• AANAT

Question 2

Which one of the following neurons contain Melanopsin?

Answer 2

• ipRG cells

(Intrinsically photosensitive Retinal Ganglion) Cells

Question 3

Where does Melatonin get produced?

Answer 3

In the PINEAL Gland in the Brain

Question 4

PVN stands for what?

Answer 4

PARA-Ventricular Nucleus

Question 5

Another name for Melatonin

Answer 5

Acetylated-Methylated Serotonin

Question 6

What connection defines the RHT (Retino-Hypothalamic Tract)

Answer 6

• ipRGC to SCN

Question 7

How do the nuclei communicate with each other?

Answer 7

Via Tracts

Question 8

Photoentrainment

Answer 8

Light Training

Question 9

What is the Purpose of the Antioxidant cascade of Melatonin

Answer 9

To Protect Against

1. OXIDATIVE Stress
   - Free radicals produced by O2
2. NITROSATIVE Stress
   - Reactive Nitric Oxide

“When OO and NO get together to OONO!!!!”

Question 10

What is the Coenzyme for the HYDROXYLATION step in Melatonin Synthesis

Answer 10

Tetra-hydro-BIOPTERIN

Question 11

Melanopsin

Answer 11

• Receptor for photos
• 460nm (Blue light)
• light hits receptor and sets of cascade of effects

Question 12

Where is the PVN located?

Answer 12

In the HYPOTHALAMUS

Question 13

Melatonin Synthesis: Reaction steps

Answer 13

Start with Tryptophan

1. HYDROXYLATION
2. DECARBOXYLATION
3. ACETYLATION
4. METHYLATION

“Hoover DAM”

Question 14

Where is the SCN located

Answer 14

• Located in the HYPOTHALAMUS
• Situated Directly ABOVE the Optic Chiasm
• 2 Nuclei

Question 15

What kind of receptors are on the Pinealocyte?

Answer 15

A/B ADRENERGIC Receptor

Question 16

What is a Direct Precursor to AMK?

Answer 16

AMFK

Question 17

What is the Photoregulated enzyme for the METHYLATION step in Melatonin Synthesis?

Answer 17

Acetyl-Serotonin-O-methyltransferase

• ASMT

Question 18

Fxn of the SCN

Answer 18

• Controls the CIRCADIAN rhythm
  (Master Oscillator)
• Influences many Physiological and Behavioral Rhythms in 24hr cycle

Question 19

What gets Produced when Melatonin Reacts with Oxidants/Radicals?

Answer 19

1. C-3-OH-Melatonin
   - Cyclic-3-Hydroxymelatonin
2. AFMK
   - N-Acetyl-N-Formyl-5-Methoxykynuramine

Question 20

What is the Neurotransmitter used on the Pineal gland?

Answer 20

Norepinephrine

Question 21

What Vitamins are ANTIOXIDANTS?

Answer 21

• Vitamin E

- Vitamin C

Question 22

What does ROS mean?

Answer 22

Reactive Oxygen species

Question 23

Where is the Intermediolateral Nucleus located?

Answer 23

In the SPINAL CORD

Question 24

What is the Coenzyme for the DECARBOXYLATION step in Melatonin Synthesis

Answer 24

Vit B6

• Pyridoxo-5-Phosphate

Question 25

What wavelength of light can be received by the Melanopsin?

Answer 25

460nm - Blue light

Question 26

Role of C3OHM and AMFK

Answer 26

- ROS Scavengers | - Lead to formation of AMK ROS Scavenger as well

Question 27

What Intermediate does the Norepinephrine act on in the Pinealocyte?

Answer 27

Seratonin

Question 28

AANT and ASMT

Answer 28

Photo-regulated enzymes in the Melatonin synthesis pathway

Question 29

Physical route from the Retina to the Pineal gland

Answer 29

1. Retinal Ganglion cells 2. SCN 3. PVN 4. Intermediolateral Nucleus 5. SCG 6. Pineal Gland

Question 30

SCN stands for what?

Answer 30

SUPRA-Chiasmatic Nucleus

Question 31

Where does photoentrainment begin with?

Answer 31

INTRINSICALLY Photosensitive Retinal GANGLION Cells - In the back of the eye

Question 32

Purpose of Photoentrainment?

Answer 32

Trains us to NOT produce Melatonin

Question 33

Melatonin Synthesis: Intermediate steps

Answer 33

1. Tryptophan 2. 5- Hydroxy-tryptophan 3. Serotonin 4. N-Acetyl-serotonin 5. Melatonin