PMID-15901782[0]Mesocortical Dopamine Neurons Operate in Distinct Temporal Domains Using Multimodal Signaling
- good paper, decent review of relevant infos in the introduction.
- they suggest that the mesocortical system transmits fast signals about reward/salience via corelease of glutamate, whereas dopamine provides a more long-term modulator of cortical processing dynamics.
- the ventral tegmental area provides dopamine to the prefrontal cortex.
- DA levels in the PFC can increase ~10x above baseline for 10's of minutes.
- these responses occur to both to unexpectedly rewarding stimuli as well as to aversive stimuli.
- brief VTA stimulation invokes a short, transient (~200ms) inhibition of PFC in vivo, and this inhibition is typically blocked by DA antagonists. from: PMID-1436485[1]
- transient inhibition begins ~20ms after VTA stimulation, which is barely enough time for activation of ionotropic receptors, let alone metabotropic DA receptors.
- MFB stimulation evoked increased DA levels and an elevation in firing of nearby striatal neurons that outlasted the period of stimulation by > 300s.
- strangely, the excitatory glutamergic response in the PFC to VTA stimulation is blocked by lesion of the MFB.
- in suppport of co-release, TH-positive neurons in rats and primates are co-reactive for glutamate.
- DA neurons can form glutamate synapses in vitro.
- check it out:
- midbrain DA neurons respond by firing a ~200ms burst of spikes to primary rewards, conditioned, or secondary rewards, rewards that are not predicted, and novel or unexpected stimuli.
- DA neurons are activated by rewarding events that are better than predicted, remain unaffected by events that are as good as predicted, and are depressed by events that are worse than predicted (yet they do not cite any refs for this... there are a bunch of refs in the prev sentence. ) see:
- stress can also increase PFC DA
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