Lecture 4 - Emotion 2 Flashcards
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
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
