L11 addiction Flashcards
Which parts are modulated by dopaminergic input?
Motor (frontal) cortex, prefrontal brain structures which are involved in ‘cognitive’ and ‘limbic’ processing (select actions) or motor intentions, forming analogous (feedback) loops through basal ganglia
Which part do the rats like to self stimulate?
Septal region
Why septal region is an effective self-stimulation site?
It will activate dopaminergic fibres of the medial forebrain bundle which travel from the ventral tegmental area to the nucleus accumbens
Nucleus accumbens is considered as part of the…
Ventral striatum, a limbic extension of putamen and caudate
What is Pavlov’s Dog used to describe?
Conditioned reflexes
What can produce automatic responses?
Unconditioned stimuli
How can conditioned stimuli produce the same responses as unconditioned stimuli does?
After a period of reinforcement learning
What is phasic dopamine?
A reward prediction error signal
What will happen to the action potentials’ firing rate when doesn’t receive the perceived reward?
Decrease
Where did the stimulating electrode implant to remote control the rat?
Each somatosensory cortex
What does the stimulating electrode stimulate except the somatosensory cortex?
The medial forebrain bundle which contains dopaminergic output fibres from the ventral tegmental area
What does the somatosensory cortex electrode do?
Tells the direction
What does the medial forebrain bundle do?
Tells the animal to predict a reward if it follows the instructions form the somatosensory electrodes
For human, when they win a gamble, which parts of the brain will have increasing activity?
Substantia nigra/ Ventral tegmental area and the ventral striatum
What synapses are highly plastic, and what can they undergo?
Cortico-striatal glutamatergic synapses and undergo long term depression/ potentiation
What can regulate the synaptic plasticity?
Dopaminergic input
What makes learning faster?
L-DOPA
What makes learning slower?
Halperidol
Which parts’ activity levels reflect reward prediction errors?
Ventral striatum and posterior putamen
Which part of the brain learn new association quicker than cortex? after decoding the neural activities in…
Caudate neurons; caudate and prefrontal cortex
If the animals predicted there is a reward, where will the burst of action potentials be?
At the trigger
If the animals receive an instruction cue preceding the reward predicting trigger stimulus, where will the burst of action potentials be?
At the instruction cue
When reward is unpredictable, dopamine neurons will…
increase more than ones expected
Cortex-basal ganglia circuits are designed to…
engrain habits of action selection which increase our chances of ‘rewarding’ outcomes
