Reward Flashcards
What is a hedonic circuit ?
a liking system
not driven by metabolism but pleasure
A component of reward
What are the components of reward?
hedonic circuit
wanting/ motivation
What triggers wanting and craving of food?
sensory cues
What are the two systems which control food intake?
Homeostasis
Reward system
What structures regulates our appetite and how ?
The hypothalamus releases Orexigenic (increase appetite) and aneorexigenic (decrease appetite)
What input does the hypothalamus receive to regulate appetites?
brainstem
pancreas
intestine
liver
What is the reward system?
neural network that receives and evaluates the rewarding properties of stimuli
Where is self stimulation observed in the brain?
Nucleus accumbens
Lateral hypothalamus
Ventral tegmental area
Cortical structures
Where does the hypothalamus get input from within the reward circuit in the brain?
medial forebrain bundle
axons project from the ventral tegmental area to nucleus accumbens
Ventral tegmental area connects to amygdala, septum and cortex
What signalling does the hedonic neural pathway use?
Opioid and endocannabinoids
What are endogenous opioids ?
neuropeptides (endorphins, dynorphins)
receptor subtypes: mu, kappa, delta
GPCR
What are the agonists and antagonists of opioids ?
Agonists = morphine antagonists = naloxone
What are endogenous endocannabinoids?
lipid molecules (anandamide and 2-arachidonylglycerol ) receptor subtypes: CB1, CB2 GPCR
Where is CB1 predominately expressed?
central nervous sytem
What does morphine do to liking responses ?
enhances liking responses
How are hedonic pathways connected?
anatomically by neural pathways
What are the hedonic hotspots ?
Parabrachial nucleus Ventral pallidum Nucleus Accumbens Insular Orbitofrontal
What happens if the ventral palladium is blocked/removed?
the liking system is lost
What is the key NT in reward?
dopamine (needed for motivational aspect of reward)
What is dopamine needed for?
needed for wanting but not needed for pleasure
Is a larger section of the brain wanting or hedonic hotspot networks?
Larger section is wanting
What structure of the brain cross talks between homeostasis and reward circuits?
lateral hypothalamus
