Neuroanatomy Draw It To Know It

18. Basal Ganglia 315

Striatum

(caudate

& putamen)

Substantia nigra

compacta

Cerebral

cortex

Globus pallidus

external segment

Subthalamic

nucleus

Globus pallidus

internal segment/

substantia nigra

reticulata

Motor

neurons

Direct

pathway

Thalamus

Indirect

pathway

D2

D1

(Dopamine)

Direct pathway - overall excitatory

Indirect pathway - overall inhibitory

DRAWING 18-4 Direct & Indirect Pathways: Circuitry