W11 - Encoding Valence 2/2

Question 1

Affective valence can be decomposed in two complementary but distinct aspects. What are they?

Answer 1

hedonic and motivational aspects

Question 2

What are the modes of affective valence for hedonic aspects?

Answer 2

pleasure
displeasure

Question 3

What are the modes of affective valence for motivational aspects?

Answer 3

appetitive
aversive

Question 4

True or false: behavioural measures cannot isolate hedonic and motivational components of affective valence

Answer 4

False: they can.

Question 5

What can be one behavioural proxy to determine hedonic responses?

Answer 5

facial expression

Question 6

What does one look for when objectively measuring motivational properties of affective valence?

Answer 6

“wanting” or “fearing” behaviours

Question 7

What is the dominant view about the encoding of valence? Modules or modes?

Answer 7

Modules (traditional region-function)

Question 8

What is the difference between affective modules and affective labelled lines?

Answer 8

No fundamental difference, same concept.

Question 9

How do affective modules and affective modes compare?

Answer 9

An affective mode is defined as one of several potential states of a single neural module

Question 10

Affective modes refer more to activity or structure?

Answer 10

Activity: an affective mode could correspond to a particular patterns of neurochemical stimulation, a pattern of genomic activation, a particular frequency or temporal pattern of electrical excitation of the module OR a particular neurobiological state of the larger circuitry within which the module is embedded

Question 11

In which subcortical region is the co-existence of both hedonic and motivational modules suspected? Mediating which valence?

Answer 11

Nucleus accumbens:

Dopamine signaling in the nucleus accumbens mediates ‘wanting’ (but not liking)

Neurotransmitter sigalling at hedonic hotspots (opioid, endocannabinoid, orexin but NOT dopamine) enhances ‘liking’

Question 12

True or false: it was shown that inside positive hedonic hotspots stimulating kappa-opioid receptors increases ‘liking’, but outside of them kappa-opioid stimulation is also aversive.

Answer 12

True

Question 13

Main projection from NAcc are of which neuronal type? To which downstream regions are they projecting?

Answer 13

GABAergic -> VTA, VP, lHypothalamus

Question 14

What are the type of inputs to NAcc? Where are they originating?

Answer 14

Glutamatergic inputs from PFC, hippocampus, amygdala, etc.

Question 15

What is the topographic distribution of motivation modules in the NAcc? Are these modules coding for the same affective functions across all conditions?

Answer 15

Rostral manipulations increase appetitive eating and can induce place preferences

Caudal manipulations generate intense defensive behaviours, such as burying, distress
calls and attacking and can induce a place aversion

NO!

Question 16

How is the encoding of affective functions changing across conditions in the NAcc?

Answer 16

In a comfortable, low- stress testing environment, appetitive behaviours can be elicited at more caudal locations

In a high-stress bright, noisy testing environment, aversive behaviours can be elicited at more rostral locations