injections of the retrograde tracer , wheat germ agglutinated-horseradish peroxidase were placed in the substantia nigra , in adjoining dopamine-containing cell groups a8 and a10 , and in the internal and external parts of the pallidal complex of 20 cats in order to identify the compartmental origins of striatal efferent projections to the pallidum and midbrain .
C0038590
substantia nigra
C0025462
midbrain