Architectionis, somatotopic organization, and ipsilateral cortical connections of the primary motor area (M1) of owl monkeys

摘要: The ipsilateral cortical connections of primary motor cortex (M1) owl monkeys were revealed by injecting WGA-HRP and fluorescent tracers into M1 sites identified intracortical microstimulation. In some the same animals, extent somatotopic organization was determined making detailed microstimulation movement maps relating results to architectonics. Thus, delineation based on a combination physiological anatomical characteristics. comprised most, but not all, rostral area 3a where movements evoked at low levels current (40 microA or less). Analysis patterns architectonics placed low-threshold in ventral premotor field (PMV) dorsomedially situated supplementary (SMA). Movements also reliably elicited from dorsal (PMD) higher currents. characterized global organization, representing hindlimb, trunk, forelimb, face mediolateral sequence, mosaic local with given typically represented several different sites. Architectonically, absence granular layer IV presence very large V pyramidal cells. However, uniform structure: cells larger caudally than rostrally, feature we used distinguish caudal (M1c) (M1r) subdivisions area. resembles Brodmann's 4, although subdivision has probably been considered as part 6 workers. Tracer injections somatotopically distributed areas PMD, PMV, SMA, well somatosensory 3a, 1, 2, S2. Weaker 3b, posterior parietal cortex, (PV), cingulate cortex. M1r M1c differed connectionally architectonically, being connected primarily areas, while strongly both non-primary These indicate that interacts directly least three six areas.