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Question 1

Serotonin (5-hydroxytryptamine; 5-HT)
• One of the biogenic amines derived from

Answer 1

tryptophan

Question 2

Serotonin (5-hydroxytryptamine; 5-HT)

Broadly distributed in the brain. Its depletion in brain →

Answer 2

depression

Question 3

Serotonin (5-hydroxytryptamine; 5-HT)
functions to regulate :

Answer 3

• Appetite,
• Sleeping, dreaming,
• Memory and learning,
• Temperature,
• Mood & emotional behavior,
• Biological clock.
• Muscle contraction,
• Functions of the CVS and endocrine systems.

Question 4

Serotonin & Depression:
Anti-depressant drugs →

Answer 4

→ ↑ serotonin levels at the synapse by
blocking the reuptake of serotonin into the presynaptic neurons.
serious side-effects.

Question 5

• If depression is mild, it can be managed by ↑ serotonin levels with

Answer 5

vigorous exercise
• A diet ↓ in omega-3 FAs → lower serotonin levels in brain→ depression.
• Complex CHO can → ↑ tryptophan in brain → calming effect.
• Vitamin C is also required for conversion of tryptophan → serotonin.
• Dietary serotonin as in banana has no effect…Why???

Question 6

Purine Derivatives as Neurotransmitters

Answer 6

They are all derived from adenine-containing nucleotides or nucleosides
(ATP, ADP, AMP & adenosine).

Question 7

ATP acts as a neurotransmitter in ……,……….

ATP regulates the

Answer 7

ATP acts as a neurotransmitter in both peripheral & CNS.
ATP regulates the release of transmitters from their synapse of origin.
ATP is released as an excitatory co-transmitter with norepinephrine from postganglionic sympathetic nerves, with acetylcholine from postganglionic parasympathetic nerves and from sensory, enteric and central neurons.

Question 8

largest group of neurotransmitters.

Answer 8

NEUROPEPTIDES

Question 9

NEUROPEPTIDES Many of them are “co-released” along with a small-molecule transmitter, but in some cases a peptide is the primary transmitter at
a synapse.
Many of the neuropeptides have a …………… residue at the N-terminus which is cyclized to form pyro-glutamate, while the C-terminus is often
an ……….

This provides better protection against

Answer 9

glutamate

acid amide (–NH 2).

This provides better protection against breakdown by peptidases.

Question 10

Substance P & Capsaicin
released from the terminals of specific sensory neurons , found in the

Answer 10

released from the terminals of specific sensory neurons , found in the brain & spinal cord , and is associated with inflammatory processes & pain.
It’s responsible for transmission of pain from certain sensory neurons to CNS

Question 11

Capsaicin (made from chili peppers) was found to ……. substance P levels at local nerve endings & ………..

Answer 11

↓ relieve pain.

Question 12

Substance P & its endogenous receptor …………….

Answer 12

Substance P & its endogenous receptor neurokinin-1 receptor (NK1R) are
widely distributed in brain & are found in brain regions that regulate
emotion.

Question 13

The …..amino acid sequence of substance P

Answer 13

11

Question 14

Neuropeptides Belong To Multigene Family

Answer 14

Neuropeptides Belong To Multigene Family
1. Pro-opio-melanocortin: contains β-endorphin.
2. Pro-enkephalin A: Contains Met- & Leu-enkephalins.
3. Prodynorphin: dynorphin.

Question 15

Endorphins and encephalins are the body’s natural

Answer 15

painkillers

Encephalins block pain signals in spinal cord. Endorphins are thought to block pain principally at the brain stem.

Question 16

The β-endorphin molecules are produced by the body as portions of larger

Answer 16

The β-endorphin molecules are produced by the body as portions of
larger pro-opio-melano-cortin (POMC) molecules, that expresses in the pituitary gland, then they are cut by enzymes into active subunits.

Question 17

β-endorphin molecules cause

Answer 17

β-endorphin molecules cause pain relieve or produce pleasure feelings.
They are called the happiness hormones.

Question 18

Pro-enkephalin A:
Met-enkephalin and leu-enkephalin are
composed of 5 amino acids joined by
peptide bonds.
They differ only in the amino acid present at

Answer 18

the C-terminal end.

Question 19

Ways to Increase Endorphins in Your Body:

Answer 19

profound relaxation in a float tank triggers the production of endorphins .
Acupuncture needles into specific body points triggers production of endorphins.
A placental tissue of fetal origin (syncytiotrophoblast), excretes β- endorphins into the maternal blood system from 3rd month of
pregnancy.

exercise regularly have higher than usual amounts of β–endorphin in their bloodstream; as their levels ↑ during exercise, pleasure feelings.