Principles of Neuroscience Lecture 27 Reward Flashcards

0
Q

Describe ‘Suppression of Behaviour’ with reference to a specific example

A

Micruration

Humans have the capability to decide when it is appropriate to urinate. We can inhibit the spinal reflex via brain input

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1
Q

Describe the divisions in descending control of emotion

A

Volitional: pyramidal projections

Non volitional, emotional: extra pyramidal

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2
Q

What did the Olds-Milner experiment show

A

There are specific regions associated with pleasure

Rats will press a lever when it causes stimulation of specific areas in the brain

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3
Q

Which regions in the brain are important for reward?

A

Ventral medial forebrain
Median forebrain bundle

Ventral tegmental area

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4
Q

Describe the limbic loop pathway

A
  1. Cortical input stimulates
  2. Striatum, nucleus accumbens, which inhibits
  3. Pallidum, which can no longer inhibit
  4. Thalamus, which activates
  5. Cortex
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5
Q

What is the role of dopamine in the limbic loop pathway?

A

Increases the activity of the loop by further activating the striatum

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6
Q

What is the role of the VTA?

A

It is the source of dopamine for the basal ganglia

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7
Q

Describe the dopaminergic pathway, and the effects of hedonic drugs on this pathway

A

Dopamine is released by neurons from the VTA terminating on striatum (nucleus accumbens)

Heroin and nicotine: stimulate the VTA to release more dopamine
Cocaine and amphetamines: stop the reuptake of dopamine by the VTA neurons. Dopamine has longer lasting effects

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8
Q

What happens to the neurons in the brain when the individual is addicted to drugs?

A

There is a decrease in basal activity

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9
Q

When the olds-Milner experiment was performed on humans, what feeling did the subjects report?

A

They reported that the effect of dopamine was an anticipation of reward, not reward itself

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10
Q

Describe the difference between wanting and enjoying with reference to a particular experiment

A

In rats who have depleted striatal dopamine, they will not seek sugar.

However, if they are given sugar, they will still enjoy it.

This shows that there are two different areas for wanting and enjoying

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11
Q

Which region is important for enjoying?

A

Ventral striatum

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12
Q

Describe the features of stimulus-reward learning

A

When we receive a reward, there is increased activity of the VTA

When we are conditioned to that reward, there is no longer an increase in activity when we receive it

If we are conditioned, and we receive the conditioned stimulus but no reward follows, there is extinction of the activity of the neurons in the VTA

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13
Q

Describe how reward undermines motivation with reference to a particular study

A

In one study there were two groups. One group received a reward when it performed an activity and the other didn’t

The second time, neither recieved a reward. The group who initially had had no motivation to perform the activityy

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14
Q

What are modulatory systems of the brain?

What are the general features?

A

A neuron regulates diverse populations of CNS neurons with various neurotransmitters

  1. Diffuse action
  2. Nuclei contain relatively few neurons
  3. Nuclei in brain stem and basal forebrain
  4. Highly divergent
  5. En passant connections
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15
Q

What are the four neuromodulatory systems?

A

Dopamine
Serotonin
Noradrenaline
Acetyl choline

16
Q

Which activities normally elicit the phasic dopamine activations of the limbic loop?

A
Food
Water
Sex
Micturition
Complex social behaviours