Parietal inputs to dorsal versus ventral premotor areas in the macaque monkey: evidence for largely segregated visuomotor pathways

Exp Brain Res. 2002 Jul;145(1):91-103. doi: 10.1007/s00221-002-1078-9. Epub 2002 Apr 30.


The lateral premotor cortex plays a crucial role in visually guided limb movements. Visual information may reach this cortical region from the parietal cortex, the highest stage in the dorsal visual stream. Anatomical studies indicate that the parietal projections to the dorsal (PMd) and ventral (PMv) premotor areas arise from separate parietal regions, supporting the notion of parallel visuomotor pathways. We tested the degree of segregation of these pathways by injecting retrograde tracers into PMd and PMv in the same monkeys, under physiological control. Eleven injections were made in four animals, and the analysis of retrograde labelling revealed that parietal cells projecting to PMd and those projecting to PMv are largely segregated. The strongest projections to PMd arise from the superior parietal lobule, including the medial intraparietal area (MIP), PEc and PGm, and the parieto-occipital area. These areas were devoid of labelling following injections into PMv, which receives its major projections from the anterior intraparietal area (AIP), area PEip, the anterior portion of the inferior parietal gyrus (area 7b), and the somatosensory areas. In addition to their strong projections to PMv, areas 7b and PEip send minor projections to PMd as well. Additional projections to PMd arise from the ventral intraparietal area and the inferior parietal lobule. The present findings are direct anatomical evidence for largely segregated visuomotor pathways linking parietal cortex with PMd and PMv.

MeSH terms

  • Animals
  • Axons / physiology
  • Axons / ultrastructure
  • Brain Mapping
  • Cholera Toxin
  • Fluorescent Dyes
  • Macaca fascicularis / anatomy & histology*
  • Macaca fascicularis / physiology
  • Macaca mulatta / anatomy & histology*
  • Macaca mulatta / physiology
  • Motor Cortex / cytology*
  • Motor Cortex / physiology
  • Movement / physiology*
  • Nerve Net / cytology
  • Nerve Net / physiology
  • Parietal Lobe / cytology*
  • Parietal Lobe / physiology
  • Psychomotor Performance / physiology*
  • Visual Pathways / cytology*
  • Visual Pathways / physiology
  • Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate


  • Fluorescent Dyes
  • Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate
  • Cholera Toxin