Anatomy of reward pathway Flashcards
what do cortical neurons do
direct goal directed behavior
what is the vSUB for
spatial and contextual control
provides amplification factor by determining proportion of DA neurons that are spontaneously active
involved in regulation of stress
What is Prefrontal cortex for
executive control
response inhibition
task switching
what is the BLA for
conditioned associations and affective drive
what is the thalamus for
sensory input
what is phasic firing
behaviorally relevant stimuli cause short term activation of dopamine cell firing
what is tonic firing
regulates the intensity of phasic dopamine response through its effects on extracellular dopamine levels
what does burst firing depend on
glutamate activation of NMDA receptors
DA neurons in spontaneously firing state
what is population activity
refers to the proportion of DA neurons that are spontaneously active
What is the limbic pathway
vSub excites NAc which inhibits VP to disinhibit DA neurons in the VTA
what is the shell of the NAc
highly involved with drug reward
what is the core of the NAc
contributes to motivated behaviors such as cue conditioning and drug seeking
what are the effects of DA neurons on NAc
inhibits NAc neurons via D2 receptors (decreases cAMP production)
increases glutamatergic drive onto NAc neurons via D1 receptors
Increases neuronal synchrony via gap junctions
(DA alters permability of connexins)
what are the excitatory inputs onto the NAc
vSub
BLA
PFC
what are the inputs to the vSub
dorsal hippocampus
PFC
BLA
what are the up states of NAc neurons
rapid large amplitude spontaneous shifts in Vm
important for context specific processes
what is vSub input to the NAc modulated by
dopamine increases vSub drive of NAc neurons
what does a disconnection of vSub and NAc result in
disrupts the acquisition of learned behaviors
what is the neuroadaptions at the binge intoxication stage
what happens during the withdrawal/ negative affect stage
involves extended amgydala which is associated with negative reinforcement of dependence
what are within system neuroadaptions
brain systems important for acute reinforcing effects of DOA become compromised and begin to contribute to a negative reinforcement mechanism
what are the changes associated with within system neuroadaptions
decreased LTP in NAc
increased trafficking of AMPA recep
Increased CREB phosphorylation and activation of cAMP
downreg. of DA D2 receptors
decreased firing of VTA DA neurons
what are between system neuroadaptions
occur in the extended amygdala including neurotransmitters associated with brain stress systems involved in negative reinforcement of dependence
what happens during preoccupation/anticipation stage
involves prefrontal cortex
impairment of executive function and drives impulsivity
GO system
engages habit systems
anterior cingulate cortex
dorsolateral prefrontal cortex
what is the anterior cingulate cortex
selection of responses; planning and self monitoring of goal direct behaviors
what is the dorsolateral prefrontal cortex
working memory, planning, strategy
what is the stop system
inhibits go system
ventrolateral prefrontal cortex
orbitofrontal cortex
what is the ventrolateral prefrontal cortex
response inhibition, sustained attention, rule generation
