Neurons, neurotransmitters, drugs and mental function

Question 1

The movement of what ion causes depolarisation?

Answer 1

Na+

Question 2

Explain the effects of a graded potential

Answer 2

The change in membrane potential is proportional to the electrical input.
i.e. Small input = small change in membrane potential, large input = large change

Question 3

What is temporal summation, and what is the effect?

Answer 3

2 inputs that arrive together close enough in time causes summation effect = graded potential larger

Question 4

What is spacial summation?

Answer 4

Arriving from 2 different places at the same time + summate when they meet (where branches come together)

Question 5

True or false: Graded potentials have to be of a certain size to create electrical event in axon

Answer 5

Yes - this is an AP

Question 6

What is an AP dependent on?

Answer 6

Whether or not the input reaches threshold

Question 7

How does the toxin Tetrodotoxin (TTX) work?

Answer 7

Works by blocking ion flow through the channels that generates action potentials

Question 8

What is a synapse?

Answer 8

the special junctions across which neurons communicate with each other

Question 9

What is an agonist drug?

Answer 9

increases the activity of a neurotransmitter

Question 10

What is an antagonist drug?

Answer 10

inhibits/decreases the action of a neurotransmitter

Question 11

What is the purpose of reuptake?

Answer 11

To give a brief pulse of info, so other states can be signaled

Question 12

Name 5 ways drugs can have affect on neurotransmission by altering the neurotransmitter.

Answer 12

Synthesis, storage, release, binding, and reuptake

Question 13

Give a general example of how drugs affecting the SYNTHESIS of neurotransmitter may decrease the PSP

Answer 13

reduction of neurotransmitter synthesised = less to be transmitted each time action potential sent

Question 14

Give a general example of how drugs affecting the STORAGE of neurotransmitter may decrease the PSP

Answer 14

leaky vesicle = less neurotransmitter across cleft = weaker message

Question 15

Give a general example of how drugs affecting the RELEASE of neurotransmitter may decrease the PSP

Answer 15

drugs can decrease the amount of neurotransmitter released and therefore the strength of the PSP

Question 16

Give a general example of how drugs affecting the BINDING of neurotransmitter may decrease the PSP

Answer 16

drugs can can block receptors = less graded potential in post cell

Question 17

Give a general example of how drugs affecting the REUPTAKE of neurotransmitter may INCREASE the PSP

Answer 17

if reuptake process inhibited, neurotransmitter molecules remain in cleft area for longer = stronger message.

Question 18

Name 2 agonists at the cholinergic synapse, and their effects on the body

Answer 18

Nicotine - high dose leads to tremors

Black Widow spider venom - causes all muscles start contracting, large enough dose = paralysis, death

Question 19

Name 2 antagonists at the cholinergic synapse, and their effects on the body

Answer 19

Scopolamine (for seasickness) - suppresses signal from vestibular system
Botulinum toxin (food poisoning) - prevents transmission at neuromuscular junction = flaccid paralysis

Question 20

Name 4 symptoms of Parkinsons disease

Answer 20

tremor, muscular rigidity, slow movements, postural instability

Question 21

What is a new treatment that helps treat parkinsons, and how does it work?

Answer 21

deep brain stimulation (DBS) - Pulse generator inside brain stimulates neurons, causing them to fire

Question 22

Name 3 positive symptoms of Schizophrenia

Note: positive symptoms = outside of normal range

Answer 22

Delusions
Hallucination
Disorganized thinking

Question 23

Name 3 negative symptoms of Schizophrenia

Note: negative symptoms = loss of normal function

Answer 23

○ Decreased emotional responses
○ Hard to generate new ideas
○ Don’t care about what other people think of them, social norms

Question 24

Name 3 cognitive symptoms of Schizophrenia

Note: cognitive symptoms = changes in cognitive function

Answer 24

Poor working memory

Disruption in executive function, attention span

Question 25

What is the relationship between Parkinsons and schizophrenia?

Answer 25

Dopamine antagonists have anti schizophrenic effects and also produce Parkinson’s symptoms

Question 26

What part of the brain is PD and schizophrenia related to?

Answer 26

substantia nigra (midbrain nucleus)

Question 27

Name the 5 ways drugs can effect neurotransmission

Answer 27

synthesis, storage, release, binding, reuptake

Question 28

if synthesis decreases…

Answer 28

reduction of neurotransmitter = less to be transmitted each time action potential sent

Question 29

If storage decreases (leaky vesicle)…

Answer 29

less neurotransmitter across cleft = weaker message

Question 30

If receptors are blocked…

Answer 30

… blocked receptors = less graded potential in post cell

Question 31

If reuptake process inhibited…

Answer 31

… neurotransmitter molecules remain in cleft area for longer = stronger message.

Question 32

What is an agonist?

Answer 32

A drug that binds to the receptor of the cell and triggers a response

• Mimics a naturally occurring substance
• Response created even without signal

Question 33

What is an indirect agonist?

Answer 33

A drug that enhances release/action of an endogenous neurotransmitter
- Increases synthesis, binding

Question 34

What is an antagonist?

Answer 34

blocks or suppress agonist-mediates responses

Question 35

How does a DBS work?

Answer 35

Pulse generator stimulates neurons, causing them to fire = smooth movement for Parkinsons patients

Question 36

What concepts did the Olds and Milner study investigate?

Answer 36

Intercranial self-stimulation (ICSS), reward systems, dopaminergic pathways