Ipsilateral intracortical connections of physiologically defined cutaneous representations in areas 3b and 1 of macaque monkeys: Projections in the vicinity of the central sulcus

摘要: This study examined cortical connections of areas 3b and 1 in 17 macaque monkeys reference to regional somatotopography. The fluorescent retrograde tracers Fast Blue Diamidino Yellow the anterograde tracer Rhodamine Dextran were injected into closely related cutaneously responsive sites primary somatosensory cortex, e. g., adjacent digits. Supra- infragranular layers nearly all studied contained labeled pyramidal cells. Labeled cells predominated at fringes a distribution where from different injections same brain intermixed more. All topographical regions across area have reciprocal with 4, 3a, 3b, 1, 2, 5. Intrinsic within between it 2 are greatest; those less. exceed other nearby projections this which reciprocally connects 2. Connections appear topographically organized, including poorly mapped regions, like These link representations neighboring skin skip map that include disjoint dermatomal areas. digit overlap; however, double-labeled not found. Distal proximal zones mostly interconnect an area. spread further than thereby joining more disparate interareal connections, project homotopically. domain over I (SI) dynamically changes following tracortical microstimulation (Recanzone, Merzenich Dinse, Cerebral Cortex 2:181-196, 1992) may depend on range intrinsic observed study. extent was less expected challenges hypothesis these directly create receptive field enlargements.