Neurophysiology of Reward and Addiction Flashcards
(54 cards)
what is salience?
something important in the surrounding environment worth paying attention to; think of salience as “wanting”
what does it mean when something has salience?
it has value to an individual
what does reward involve?
hedonic (euphoric) effect of pleasure, motivation to obtain the reward because of its salience, and associated learning
what is aversion?
a negative reinforcement of behavior that the individual will learn to avoid future encounters
what is anhedonia?
lack of interest in something; no longer liking something previously liked- prominent feature in depression
an unpredicted award elicits what?
a positive prediction error
a fully predicted reward elicits what?
no response- no discrepancy associated with it
omission of a predicted reward induces what?
a depression (negative prediction error)
why is reward prediction error important?
it is going to highlight the difference between expected rewards and the experiences that induce either the expectation, omission, or fully-predicted value
drugs of abuse increase what?
extracellular dopamine concentrations in limbic regions, including the nucleus accumbens
what are some examples of drugs that increase dopamine directly?
cocaine, amphetamine, methamphetamine, and ecstasy
how do some drugs increase dopamine directly?
by inhibiting dopamine reuptake or promoting dopamine release
what are some drugs that increase dopamine indirectly?
nicotine, alcohol, opiates, and marijuana
what does salience affect?
the motivation to seek the anticipated reward and it facilitates conditioned learning
what are the effects of sensory stimuli associated with salience?
the sensory stimuli (sights or sounds) that are associated with salience (a drug or drug taking) can increase dopamine by themselves and elicit the desire for the drug
what is the important system involved in the neurophysilogic system of reward?
the mesolimbic system
what is the mesolimbic system made up of?
the nucleus accumbens, the ventral tegmental area, the prefrontal cortex, and the limbic system
what is the main function of the nucleus accumbens?
to suppress sensations of pleasure and reward
what type of neurons are nucleus accumbens neurons?
they are gabaergic
what is the nucleus accumbens constitutively being activated by?
a constant trickle of EAA like glutamate from the hippocampus, amygdala, or the pre-frontal cortex
what happens when the nucleus accumbens is activated?
they will be stimulated to release GABA upon their target
where do the GABAergic nucleus accumbens neurons project to and release GABA when stimulated?
the pre-frontal cortex
what is the effect of a constitutive inhibition of the PFC targets?
it keeps the brain in a reward-neutral state (no pleasure sensed)
what brain areas activate the nucleus accumbens?
hippocampus, amygdala, the PFC
