Cortical projection to hand-arm motor area from post-arcuate area in macaque monkeys: a histological study of retrograde transport of horseradish peroxidase.

In four macaque monkeys horseradish peroxidase (HRP) was injected into physiologically defined hand-arm motor area. Ipsilaterally, HRP labeled neurons were found in both upper and lower limbs of the posterior bank of the arcuate sulcus and in an area surrounding the arcuate spur. Contralaterally, labeled neurons were found in the same areas, though less dense in concentration. Labeled neurons were found mostly in layer III of the cortex.