Neuromodulators and Arousal

Question 1

What is the role of a neuromodulator?

Answer 1

Lecture 21, slide 2

Question 2

What is arousal? Give an example.

Answer 2

Lecture 21, slide 5-6

Question 3

What role does 5-HT have in arousal?

Answer 3

Lecture 21, slide 7-8

-higher firing rate of 5-HT neurons when awake. So more 5-HT when awake.

Question 4

What role does ACh have in arousal?

Answer 4

Lecture 21, slide 9-10

Question 5

What role does noradrenaline have in arousal?

Answer 5

Lecture 21, slide 11-12

Question 6

How does Eban-Rothschild et al. use fibre photometry combined with EEG/EMG recordings to show the VTA DA neurons change their activity during sleep-wake states?

Answer 6

Lecture 21, slide 13-24

Question 7

What are DREADDs? Give an example of one.

Answer 7

Lecture 21, slide 26

• an example of chemogenetics/pharmacogenetics
• hM4Di is a modified form of the human M4 muscarinic (hM4) receptor. It is an inhibitory receptor/DREADD. It can be activated by CNO.

Question 8

How does Eban-Rothschild et al. use DREADDs combined with EEG/EMG recordings to show that VTA DA neurons are necessary for wakefulness?

Answer 8

Lecture 21, slide 25-33

Question 9

How does Eban-Rothschild et al. use fibre photometry and DREADDs to show that VTA DA neurons are necessary for arousal responses to salient stimuli?

Answer 9

Lecture 21, slide 34-38

-inhibiting DA neurons, suppresses the arousal response

Question 10

How does Eban-Rothschild et al. use DREADDs to show that inhibition of VTA DA neurons leads to complex sleep-related behaviours in a context-dependent manner?

Answer 10

Lecture 21, slide 39-42
-inhibition of VTA DA neurons has different effects on sleep-wake states depending on the context (e.g. homecage vs novel cage)

Question 11

How does Eban-Rothschild et al. use optogenetics combined with EEG/EMG recordings to show that activation of VTA DA neurons initiates wakefulness?

Answer 11

Lecture 21, slide 43-55

Question 12

How does Eban-Rothschild et al. use optogenetics to identify which neural pathway(s) mediate arousal?

Answer 12

Lecture 21, slide 56-60

Question 13

What role do neuromodulators have in arousal?

Answer 13

Lecture 21, slide 62

Question 14

What is the Yerkes-Dodson Law? What is the relationship between performance and arousal in simple and difficult tasks? How did they show this?

Answer 14

Lecture 21, slide 63-70

Question 15

Describe studies that show the relationship between learning and stress follows the Yerkes-Dodson Law.
Give a potential explanation as to why high-to-very-high stress/arousal impairs perfornance/learning.

Answer 15

Lecture 21, slide 72-83

Question 16

Describe studies that show that the relationship between DA and working memory/PFC activity follows the Yerkes-Dodson Law.

Answer 16

Lecture 21, slide 84-92