BCH 313 Neurochemistry

Question 1

What is neurochemistry

Answer 1

Neurochemistry includes the study of neurochemicals influencing the function of neurons and forming the network of neural operation

Question 2

Properties of neurotransmitters

Answer 2

1. synthesized in the presynaptic neuron
2. Localized to vesicles in the presynaptic neuron.
3. Released from the presynaptic neuron under physiological conditions.
4. Rapidly removed from the presynaptic cleft by uptake or degradation.
5. Presence of receptor on the post synaptic neuron.
6. Binding to the receptor elicits a biological response.

Question 3

Biochemical classification of neurotransmitters

Answer 3

A. Small molecule neurotransmitters (acts rapidly, an acute response)

B. Neuropeptide transmitters (acts slowly and prolonged effect)

Question 4

Classes of small molecule neurotransmitters

Answer 4

Class I: acetylcholine

Class II: biogenic amines
Catecholamines: epinephrine, norepinephrine, dopamine.
Serotonin
Histamine

Class III: amino acid neurotransmitters:
Gabba amino Bric acid
glycine
glutamate
aspartate

Class IV: nitrous oxide

Question 5

Neuropeptide transmitters

Answer 5

Neuroactive peptides
Pituitary peptides
Peptides acting on the gut and the brain
Neuropeptides from other tissues

Question 6

Excitatory neurotransmitters

Answer 6

Acetylcholine
aspartate
dopamine
histamine
Norepinephrine
Epinephrine
Glutamate
Serotonin

Question 7

Inhibitory neurotransmitters

Answer 7

GABA
Glycine

Question 8

Function of acetylcholine

Answer 8

Vasodilation
cardiac inhibition
G.I. peristalsis
control of thoughts, mood, sleep, muscles, bladder, sweat glands
reward
memory
short term learning

Question 9

Discuss serotonin

Answer 9

Serotonin 5 hydroxytriptamine
Also known as five HT
known to control impulse emotional and behavior
increase levels lead to aggression. Reduce level may reduce suicidal thoughts
involved in sleep and depression

Question 10

Norepinephrine/noradrenaline

Answer 10

Noradrenaline normally produces effects such as increased heart rates, increased blood pressure, dilation of pupils, dilation of air passages in the lungs and narrowing of blood vessels in non-essential organs. This enables the bodies to perform well in stressful situations. Increases level of energy, interest, and mood.

Question 11

Discuss dopamine

Answer 11

Involved in movement, attention and learning, drive, desire motivation & pleasure/reward
• Dopamine imbalance also involved in schizophrenia
• Loss of dopamine- producing neurons is cause of Parkinson’s Disease

• Dopamine interacts with receptors on some peripheral nerve fibers and many central neurons (eg, in the substantia nigra, midbrain, ventral tegmental area, and hypothalamus).
• After release and interaction with receptors, dopamine is actively pumped back (reuptake) into the nerve terminal.

Question 12

GABA

Answer 12

It is primarily an inhibitory neurotransmitter responsible for Sleep, prevents anxiety & stress signals & has an overall calming effect on the brain.
• It has three receptors GABAb GABAc
& GABAa

Question 13

7 processes of neurotransmitter action

Answer 13

1. Neurotransmitter molecules are synthesized from precursors under the influence of enzymes.
2. Neurotransmitter molecules are stored in vesicles.
3. Neurotransmitter molecutes that leak from their vesicles are destroyed by enzymes.
4. Action potentials cause vesicles to fuse with the presynaptic membrane and release their neurotransmitter molecules into the synapse.
5. Released neurotransmitter molecules bind with autore-ceptors and inhibit subsequent neurotransmitter release.
6. Released neurotransmitter molecules bind to postsynaptic receptors.
7. Released neurotransmitter molecules are deactivated either by reuptake or enzymatic degradation.