Lecture 4 - Emotion 2 Flashcards Preview

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Flashcards in Lecture 4 - Emotion 2 Deck (32)
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What is a reward

Object or event elicit approach and worked for

Associated with wanting and liking


Define the difference between wanting and liking

Wanting: feeling desire and approach behaviours

Liking: feeling pleasure - explicit and other objective responses implicit - facial expressions


What are alteration brain substrates reward related processes underlying of

Mechanisms underlying addiction
Anhedonia - failure want things or pleasure


Outline the different techniques to identify brain substrates of reward

Instrumental conditioning

Intracranial electrical self stimulation

Intracranial drug self administration

Intracerebral micro dialysis


Outline technique of instrumental conditioning to identify brain substrates of reward

Appetitive - operational conditioning
Defined rewards something work for
Measure how much animal presses lever for reward
See what finds rewarding and how modulated in brain


Outline technique of intracranial electrical self stimulation to identify brain substrates of reward

Implant electrodes different regions brain and animal presses lever stimulate that brain rhino
Indicates signals reward
Map brain reward areas


Outline technique of intracranial drug self administration to identify brain substrates of reward

Loon whether animal self administer drugs of neural active compounds into specific areas brain
Understand neuropharmacology reward specific brain regions
If administer stimulates D1 receptors particular area means D1 receptors area brain signal reward


Outline technique of intracerebral micro dialysis to identify brain substrates of reward

Measure NTs associated rewards - neurochemical changes reward
Flush liquid can Pass through semipermeable membrane in region brain collect liquid end
Analyse for levels NTs


Outline the role of the nucleus accumbens and dopamine with reward

Nucleus accumbens part striatum sub cortical areas brain
Revived strong dopamine projections from VTA
Rewards signalled increased dopamine transmission in nucleus accumbens


How are rewards signalled in nucleus accumbens

Increased dopamine transmission in nucleus accumbens


Outline electrical stimulation in nucleus accumbens dopamine and reward

Electrical stimulation of self stimulation sites in VTA increases accumbal dopamine levels measured in vivo micro dialysis
Self stimulate origin dopamine projection leads increased dopamine transmission nucleus accumbens


Outline Food in nucleus accumbens dopamine and reward

Food increase accumbal dopamine
Animal finishes eating nucleus accumbens dopamine decreases


Outline Drugs of Abuse in nucleus accumbens dopamine and reward

Drugs = Strongly rewarding
Increase accumbal dopamine
Hijacking brain
Found amphetamine cocaine morphine ethanol and nicotine


What occurs when there is a blockade of accumbal dopamine transmission

Blocks behavioural effects of rewards
Unresponsive to rewards


What does naturally rewarding stimuli activate

Activate VTA and nucleus accumbens
Not tells us of NTs involved or dopamine


Outline Schott et al 2008 PET scan study on dopamine transmission

Radioactively labelled dopamine bonding receptor Raclopride
Binding in brain inversely related amount dopamine endogenously in brain
Less binding = more dopamine


Outline Meso-corticolimbic dopamine system in brain reward circuitry

Rewards increase NAC dopamine
Systematic and intra-NAC dopamine antagonists block responses normally maintained by reward


Outline Chrolonergic projection from PPTg to VTA modulators system for brain reward circuitry

Electrical self stimulation activated dopamine system
Chrolonergic drugs self administered in to VTA
Similar how self administer nicotine
Drives dopamine system


Outline Glutamate projections from mPFC to VTA of brain reward circuitry

Electrical self stimulation

Stimulate dopamine release in Nucleus Accumbens


What does how much a subject working for a reward tell us

How much subject works for reward may reflect wanting or desire for reward


Outline facial expressions as measures of liking

Facial expressions to Sweet or bitter tastes serve as objective and direct measures liking

Sweet = produce tongue
Bitter = open mouth gasping


What area brain is responsible for liking

Nucleus accumbens shell: role of opioid receptors I’m liking please
Inject morphine into nucleus accumbens in shell increases liking


What is the response of dopamine with inducing liking

Dopamine receptor agonist - amphetamine
Increases dopamine transmission injected in brain
Increases dopamine in nucleus accumbens
Decreases liking and increases disliking
Not induce pleasure


What is the response of dopamine and amphetamine with wanting

Amphetamine increases wanting


Outline conditioned experiment of amphetamine increasing wanting

Tone triggered sucrose pellets
Enhance appetitive instrumental response by CC stimulus = enhances wanting
Press sucrose lever more vigorously in presence CC
Enhanced administration dopamine agonist in nucleus accumbens increases wanting
Opioid making us enjoy it and experience pleasure


Outline the overlap between brain substrates of positive and negative emotions

Dopamine and nucleus accumbens important roles fear related processes addition reward related states


What does the conditioned fear paradigm combine

Conditioned fear paradigm combine manipulation forebrain dopamine system
Find dopamine manipulations many areas amygdala MPFC and nucleus accumbens affect formation or expression conditioned fear


Outline DNQX injection in the overlap between brain substrates positive and negative emotions

Antagonist mess with glutamate signalling in nucleus accumbens
Depending if injected anterior or posterior nucleus accumbens depends on effects
Elicits both appetitive and defensive behaviours
Posterior = defensive
Anterior = appetitive
Effects mediated by dopamine


Outline the amygdala and overlap between brain substrates of positive and negative emotions

Amygdala key role in fear related responses
Been implicated in responses appetitive stimuli
Drives responses


Functional Implications overlap between brain substrates of positive and negative emotions

Common currency emotion enable brain generate adaptive responses based integrated assessment positive negative stimuli in parallel

Dopamine nucleus accumbens and amygdala no specific role emotion may contribute fundamental cog processes associated both aversive and appetite stimulus
- salience signalling and attention