Brain & Behaviour - Neurons etc.

Question 1

Describe the structure of a neuron

Answer 1

> dendrites receive info
axon sends signals
synapses = where neurons communicate

Question 2

Neuron signalling is ___?

Answer 2

electrical [ions] and chemical [neurotransmitters]

Question 3

How does the cell maintain resting potential?

Answer 3

regylated by ion channels + pumps - creates an EC gradient

Question 4

Describe what happens at the synapse

Answer 4

Neurotransmitters bind to the postsynaptic ion channels.

• chemical change opens ion channels
• changes the electrical potential of the cell

Question 5

Define summation

Answer 5

• multiple axons sending information to add up

- creates a large influx of +ve ions

Question 6

Describe the 4 stages in forming an action potential

Answer 6

• resting potential: inside of membrane is -ve
• depolarisation: Na+ channels open, positive ions enter
• repolarisation: Na+ channels close, K+ channels open.
• Na+ pumped out

Question 7

What is the ‘all-or-nothing’ principle?

Answer 7

Means that the action potential must exceed the threshold otherwise no AP is generated.

Question 8

How do drugs + toxins alter neurotransmitter action?

Answer 8

Agonists: ENHANCE
Antagonists: INHIBIT

Question 9

Example of an agonist

Answer 9

morphine @ opiod receptors

Question 10

Example of antagonist

Answer 10

curare blocking Ach at neuromuscular junctions

Question 11

What 2 ways are neurotransmitters controlled in synapses?

Answer 11

REPUTAKE: NT effects stopped by recycling the NT into presynaptic neurons

ENZYME DEACTIVATION: enzymes destroy NT

Question 12

Where is GLUTAMATE found?

Answer 12

all over the brain

Question 13

What type of NT is GLUTAMATE?

Answer 13

EXCITATORY

Question 14

What can GLUTAMATE cause?

Answer 14

ischemic strokes

• blockage of blood vessels
• no oxygen = glutamate blocks synaptic cleft
• causes neurotoxicity

Question 15

Why is GLUTAMATE useful?

Answer 15

enhances taste of food
MSG > Stimulates neurons so food flavour increases
large doses = HEADACHES

Question 16

How does GLUTAMATE affect memory?

Answer 16

Blocks the NMDA Glutamate receptor - prevents new info storage

Question 17

What type of NT is GABA?

Answer 17

INHIBITORY

Question 18

What are the 3 drugs related to GABA?

Answer 18

• Barbiturates (dec. seizures)
• Benzodiazepines (tranquilsers, valium)
• Alcohol (dec. anxiety)

Question 19

How do GLUTAMATE + GABA work together?

Answer 19

• controls the brain’s overall excitation levels

Question 20

Where is SEROTONIN derived from?

Answer 20

Food

Question 21

Where is SEROTONIN produced?

Answer 21

Raphe nuclei

Question 22

Where does SEROTONIN project to? [5 PLACES]

Answer 22

• Hippocampus
• hypothalamus
• amygdala
• striatum
• thalamus

Question 23

How does SEROTONIN link to insomnia?

Answer 23

destruction of serotonin systems = insomnia

Question 24

What is the link between depression + serotonin?

Answer 24

some people believe depression = a lack of serotonin

Question 25

How is SEROTONIN affected by LSD?

Answer 25

• lock + key mechanism

- prevents normal function of seratonin

Question 26

What can happen if theres an issue w/ seratonin pathways?

Answer 26

• OCD
• Anxiety
• Depression

Question 27

Where is DOPAMINE found?

Answer 27

Basal ganglia

frontal

Question 28

What is DOPAMINE responsible for?

Answer 28

• rewards
• movement
• drug addiction

Question 29

How is dopamine linked to drug addiction?

Answer 29

More dopamine in synapse = more pleasure
makes our bodies work to this ^ level of pressure
nervous system dec. no. of dopamine receptor sites
addicts take more drugs to feel good

Question 30

How is dopamine linked to movement|?

Answer 30

Parkinsons = too little DA (can't move)
Schizophrenia = too much (move too much)