Postnatal Development of Intrinsic Horizontal Axons in Macaque Inferior Temporal and Primary Visual Cortices.
Two distinct areas along the ventral visual stream of monkeys, the primary visual (V1) and inferior temporal (TE) cortices, exhibit different projection patterns of intrinsic horizontal axons with patchy terminal fields in adult animals. The differences between the patches in these 2 areas may reflect differences in cortical representation and processing of visual information. We studied the postnatal development of patches by injecting an anterograde tracer into TE and V1 in monkeys of various ages. At 1 week of age, labeled patches with distribution patterns reminiscent of those in adults were already present in both areas. The labeling intensity of patches decayed exponentially with projection distance in monkeys of all ages in both areas, but this trend was far less evident in TE. The number and extent of patches gradually decreased with age in V1, but not in TE. In V1, axonal and bouton densities increased postnatally only in patches with short projection distances, whereas in TE this density change occurred in patches with various projection distances. Thus, patches with area-specific distribution patterns are formed early in life, and area-specific postnatal developmental processes shape the connectivity of patches into adulthood.
Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Toyonaka, Osaka 560-8537, Japan.|The Allen Institute for Brain Science, Seattle, WA 98109, USA.
Quanxin
Q
Wang
Department of Cognitive Neuroscience, Osaka University Medical School, Suita, Osaka 565-0871, Japan.|Center for Transdisciplinary Research, Niigata University, Niigata, Niigata 950-2181, Japan.
Hisashi
H
Tanigawa
Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Toyonaka, Osaka 560-8537, Japan.|Department of Cognitive Neuroscience, Osaka University Medical School, Suita, Osaka 565-0871, Japan.|Graduate School of Frontier Biosciences and Center for Information and Neural Networks, Osaka University and National Institute of Information and Communications Technology, Suita, Osaka 565-0871, Japan.
Ichiro
I
Fujita
D000818:Animals; D001369:Axons; D008251:Macaca; D009434:Neural Pathways / Q000254:growth & development*; D055495:Neurogenesis; D013702:Temporal Lobe / Q000254:growth & development*; D014793:Visual Cortex / Q000254:growth & development*
axonal morphology; column; exponential distance rule; horizontal connections