Direct Pathway

Question 1

Describe this pathway

Answer 1

Excitatory info comes from cortex to the striatum
From there, inhibitory neurons project directly to the globus pallidus internus
Globus pallidus internus sends inhibitory neurons to the Thalamus
So less inhibition is sent to the Thalamus, therefore the Thalamus can send more excitatory info to the cortex
Substantia nigra sends excitatory dopamine to the striatum, taken by d1 receptors which enhances the excitation loop

Question 2

What is the overall net effect of this pathway

Answer 2

Excite the cortex

Promote movement