Communication in the Brain

Question 1

How do signals move from one end of a neuron to another?

Answer 1

Processing electrical signals

Question 2

What did Luigi Galvani discovered?

Answer 2

Discovered that animals can move due to electricity. He realized that a frog’s leg twitched when touched by a metal probe.

Question 3

What did Volta add to Galvani’s theory?

Answer 3

Correctly proposed that the frog’s leg twitched because of the small electrical current that the metal probe had.

Question 4

What was the conclusion made after Galvani’s and Volta’s discoveries?

Answer 4

It was found out that muscles could be stimulated directly, but the effect was even stronger if the muscle nerve was stimulated.

Question 5

What is electricity?

Answer 5

electrically-charged particles move from one place to another.

Question 6

What is electrical potential? What is its unit?

Answer 6

The tendency to move. It measured in volts.

Question 7

What is the resting potential of a neuron?

Answer 7

• 70 mv

Question 8

When a neuron is in resting potential, it is…

Answer 8

polarized

Question 9

What happens when the sodium channels open and a bunch of positively charged ions (cations) rush in?

Answer 9

The neuron becomes depolarized.

Question 10

What is an ion?

Answer 10

A molecule or ion with a net electrical charge, depending on the gain or loss of one or more electrons.

Question 11

How do neurons send signals?

Answer 11

Action potential

Question 12

Why is depolarization a positive feedback loop?

Answer 12

When one area becomes depolarized, this causes a chain reaction and causes other areas to also become depolarized.

Question 13

What happens when a neuron reaches -50mv?

Answer 13

An action potential will happen, no matter what.

Question 14

How long does an action potential last?

Answer 14

One millisecond

Question 15

What is the speed of an action potential?

Answer 15

30 to 120m/s

Question 16

How is information passed from one neuron to another?

Answer 16

Through the synapse, which is part of chemical communication

Question 17

What is the synapse?

Answer 17

Contact point between two neurons.

Question 18

What is the synapse also known by?

Answer 18

Inter-neuron information transfer

Question 19

What is the synapse made up of?

Answer 19

Synaptic cleft, post-synaptic neuron and pre-synaptic neuron.

Question 20

Example of an inhibitory neurotransmitter

Answer 20

GABA

Question 21

Example of an excitatory neurotransmitter

Answer 21

Glutamate

Question 22

What do excitatory post-synaptic potentials do?

Answer 22

increases the chances of an actional potential happening again.

Question 23

What do inhibitory post-synaptic potentials do?

Answer 23

Decreases the chances of an action potential happening again.

Question 24

What is temporal summation?

Answer 24

How close together the EPSPs are in time or space determines whether action potential will occur or not.

Question 25

What are the major classes of neurotransmitters?

Answer 25

Aminoacids, peptides, monoamines and others

Question 26

What neurotransmitters fall under "aminoacids"?

Answer 26

y-aminobutyric acid (GABA), glutamate, and glycine

Question 27

What neurotransmitters fall under "monoamines"?

Answer 27

norepinephrine (NE), epinephrine (EP), serotonin (5-HT), and dopamine (DA)

Question 28

What neurotransmitters fall under "peptides"?

Answer 28

oxytocin, vasopressin and neuropeptide Y

Question 29

What neurotransmitters fall under "others"?

Answer 29

Acetylcholine (Ach), adenosine, anandamide, nitric oxide

Question 30

What would happen if neurotransmitters remained in the synaptic cleft?

Answer 30

They would keep stimulating the post-synaptic neuron

Question 31

What are the 4 major ways used to deactivate neurotransmitters?

Answer 31

Diffusion, degradation, reuptake and glial cells

Question 32

What is diffusion?

Answer 32

Some of the neurotransmitters float away from the synaptic cleft, which prevents from continuing to stimulate the post-synaptic neuron.

Question 33

What is reuptake?

Answer 33

Specialized proteins, known as reuptake transporters, take neurotransmitters back into the pre-synaptic neuron to recycle them.

Question 34

What is degradation?

Answer 34

Specialized enzymes break neurotransmitters down into inactive molecules.