TY - JOUR
T1 - Corticocortical efferent systems in the monkey
T2 - A quantitative spatial analysis of the tangential distribution of cells of origin
AU - Caminiti, Roberto
AU - Zeger, Scott
AU - Johnson, Paul B.
AU - Urbano, Antonio
AU - Georgopoulos, Apostolos P.
PY - 1985/11/22
Y1 - 1985/11/22
N2 - The laminar and tangential distributions of association neurons projecting from areas 4 and 6 of the frontal lobe to area 5 of the superior parietal lobule were studied in macaque monkeys by using horseradish peroxidase histochemistry. In both areas 4 and 6 association neurons were medium‐large pyramidal cells of layers II and III, and pyramidal and fusiform cells of layers V‐VI. Tangentially, they were distributed unevenly over the cortical surface occupying only certain parts of areas 4 and 6, including the dorsomedial part of area 6, the proximal arm region of Woolsey's M1 map, parts of the postarcuate cortex, and the supplementary motor area. Within these projection zones, the number of projection cells waxed and waned in a periodic fashion. Quantitative methods, including spectral analysis techniques, were used to characterize precisely spatial periodicities along the rostrocaudal dimension. The same quantitative analyses were used to determine the nature of the tangential distribution of corticocallosal cells of area 5 projecting to contralateral area 5. Both association and callosal spectra contained a strong component in the range of low spatial frequencies, corresponding to periods greater than 2 mm. Moreover, a consistent peak was observed in both spectra at spatial frequencies corresponding to periods ranging from 0.85 to 1.28 mm. This peak is in accord with the hypothesis of a modular organization of the cells of origin of these projection systems.
AB - The laminar and tangential distributions of association neurons projecting from areas 4 and 6 of the frontal lobe to area 5 of the superior parietal lobule were studied in macaque monkeys by using horseradish peroxidase histochemistry. In both areas 4 and 6 association neurons were medium‐large pyramidal cells of layers II and III, and pyramidal and fusiform cells of layers V‐VI. Tangentially, they were distributed unevenly over the cortical surface occupying only certain parts of areas 4 and 6, including the dorsomedial part of area 6, the proximal arm region of Woolsey's M1 map, parts of the postarcuate cortex, and the supplementary motor area. Within these projection zones, the number of projection cells waxed and waned in a periodic fashion. Quantitative methods, including spectral analysis techniques, were used to characterize precisely spatial periodicities along the rostrocaudal dimension. The same quantitative analyses were used to determine the nature of the tangential distribution of corticocallosal cells of area 5 projecting to contralateral area 5. Both association and callosal spectra contained a strong component in the range of low spatial frequencies, corresponding to periods greater than 2 mm. Moreover, a consistent peak was observed in both spectra at spatial frequencies corresponding to periods ranging from 0.85 to 1.28 mm. This peak is in accord with the hypothesis of a modular organization of the cells of origin of these projection systems.
KW - Fourier analysis
KW - association efferent zone
KW - callosal efferent zone
KW - tangential distribution of efferent cortical neurons
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U2 - 10.1002/cne.902410402
DO - 10.1002/cne.902410402
M3 - Article
C2 - 4078039
AN - SCOPUS:0022360222
SN - 0021-9967
VL - 241
SP - 405
EP - 419
JO - Journal of Comparative Neurology
JF - Journal of Comparative Neurology
IS - 4
ER -