putamen in striatum - basal ganglia#circuitry
excitatory to D1 receptors (go units)
inhibitory to D2 receptors (no-go units)
dopaminergic cells
as in the ventral tegmental area, a medial extension of the pars compacta
source of dopamine for the basal ganglia
cell rich zone
many neurons containing dopamine and melanin pigments
melanin gives the substantia nigra its dark appearance
pars compacta is the part that gets damaged in Parkinson disease
its dopaminergic neurons project to go and no-go units in the striatum
excite the direct pathway and inhibit the indirect pathway
- > increased activity in the thalamus (in both cases)