after putaminonigral injections subthalamic cells containing the tracer injected in the putamen ( about 75-80 % of all retrogradely labeled neurons ) occurred in the dorsolateral two-thirds of the nucleus , whereas those containing the tracer injected in the substantia nigra ( about 20-25 % of all positive subthalamic cells ) were confined to the ventromedial third of the structure .
C0007634
cells
C0007610
nucleus