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Intrinsic connections in the caudal subdivision of the dorsolateral visual area (DL C ) in squirrel monkeys
Author(s) -
Weller Rosalyn E.,
White Dreama M.,
Walton Mark M.G.
Publication year - 2000
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/(sici)1096-9861(20000424)420:1<52::aid-cne4>3.0.co;2-o
Subject(s) - biology , dorsolateral , squirrel monkey , neuroscience , subdivision , anatomy , cognition , history , archaeology , prefrontal cortex
Patterns of intrinsic connections and features of individual intrinsic axons in the caudal subdivision of the dorsolateral visual area (DL C ) were investigated in four squirrel monkeys ( Saimiri ) following extracellular injections of the tracers biocytin, biotinylated dextran amine, and wheat germ agglutinin conjugated to horseradish peroxidase. Injections were defined in DL C by reference to architectonic borders and patterns of connections with other cortical areas. Intrinsic connections extended up to 6 mm from an injection and were usually anisotropic, extending farther dorsoventrally than anteroposteriorly. Injections that involved the supragranular layers produced up to 20 mainly supragranular patches of projections that had a width of 285 ± 8 μm (mean ± standard error) and area of 0.125 ± 0.016 mm 2 . Seventy‐four intrinsic axon segments with a total of 3,290 boutons were drawn and their bouton spacing measured. The sample included axons in layers 1, 2–3, 5, and multiple (>2) layers; horizontally and vertically oriented axons; and axons in an injection halo, patch, or nonpatch region of projections. There were no differences in bouton spacing for axons in halo, patch, or nonpatch regions. Layer 1 axons (n = 7) had a significantly sparser distribution of boutons (median interbouton interval of 45.2 ± 17.8 μm) than the layers 2–3 (n = 35) and layer 5 axons (n = 26), which did not differ in bouton spacing (median interbouton intervals of 8.1 ± 0.4 μm and 8.4 ± 0.8 μm, respectively). Patterns of intrinsic connections in DL C are related to neural organization and properties reported for DL or visual area V4, and are compared to intrinsic connections of other areas. J. Comp. Neurol. 420:52–69, 2000. © 2000 Wiley‐Liss, Inc.