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Chapter 2
Box 2.2 | Dopamine
Neuroimaging tools (e.g. functional MRI (fMRI);
box 2.4
and TMS;
box 2.5
) provide
valuable insight in the brain regions involved in the execution of tasks or in the connectivity
between regions. Although fMRI BOLD might correlate with changes in dopamine
(Knutson and Gibbs, 2007) and TMS can induce changes in dopamine release in the
striatum (Strafella et al., 2003), these methods alone do not provide direct evidence for the
involvement of any given neurotransmitter system. Ideally then, to assess the involvement
of dopamine in the anticipation of reward, one would want to administer a drug that
manipulates the dopamine system.
Axon
terminal
of a
dopamine
neuron
VTA/SN
dopamine
post-synaptic dopamine D1 receptor
post-synaptic dopamine D2 receptor
pre-synaptic dopamine D2 receptor
dopamine transporter (DAT)
Post-synaptic: Striatal MSN neuron
Glutamatergic neuron
PFC
Bromocriptine
(high dose)
Methylphenidate
Bromocriptine
(low dose)
B
D
C
E
A
is gure was inspired by: Marieke van der Schaaf (2014)
Dopaminergic modulation of reward and punishment learning (PhD thesis)
more inhibition of the cortex
e.g. enhanced exible behavior
blocking bromocriptine -
induced e ects
e.g. no longer enhanced
exible behavior
less inhibition of the cortex
e.g. favoring stable
representations
more inhibition of the cortex
e.g. enhanced exible behavior
Sulpiride