TY - JOUR
T1 - Organization of ocular dominance and orientation columns in the striate cortex of neonatal macaque monkeys
AU - Blasdel, Gary
AU - Obermayer, Klaus
AU - Kiorpes, Lynne
PY - 1995
Y1 - 1995
N2 - Previous work has shown that small, stimulus-dependent changes in light absorption can be used to monitor cortical activity, and to provide detailed maps of ocular dominance and optimal stimulus orientation in the striate cortex of adult macaque monkeys (Blasdel & Salama, 1986; Ts'o et al., 1990). We now extend this approach to infant animals, in which we find many of the organizational features described previously in adults, including patch-like linear zones, singularities, and fractures (Blasdel, 1992b), in animals as young as 31/2 weeks of age. Indeed, the similarities between infant and adult patterns are more compelling than expected. Patterns of ocular dominance and orientation, for example, show many of the correlations described previously in adults, including a tendency for orientation specificity to decrease in the centers of ocular dominance columns, and for iso-orientation contours to cross the borders of ocular dominance columns at angles of 90 deg. In spite of these similarities, there are differences, one of which entails the strength of ocular dominance signals, which appear weaker in the younger animals and which increase steadily with age. Another, more striking, difference concerns the widths of ocular dominance columns, which increase by 20% during the first 3 months of life. Since the cortical surface area increases by a comparable amount, during the same time, this 20% expansion implies that growth occurs anisotropically, perpendicular to the ocular dominance columns, as the cortical surface expands. Since the observed patterns of orientation preference expand more slowly, at approximately half this rate, these results also imply that ocular dominance and orientation patterns change their relationship, and may even drift past one another, as young animals mature.
AB - Previous work has shown that small, stimulus-dependent changes in light absorption can be used to monitor cortical activity, and to provide detailed maps of ocular dominance and optimal stimulus orientation in the striate cortex of adult macaque monkeys (Blasdel & Salama, 1986; Ts'o et al., 1990). We now extend this approach to infant animals, in which we find many of the organizational features described previously in adults, including patch-like linear zones, singularities, and fractures (Blasdel, 1992b), in animals as young as 31/2 weeks of age. Indeed, the similarities between infant and adult patterns are more compelling than expected. Patterns of ocular dominance and orientation, for example, show many of the correlations described previously in adults, including a tendency for orientation specificity to decrease in the centers of ocular dominance columns, and for iso-orientation contours to cross the borders of ocular dominance columns at angles of 90 deg. In spite of these similarities, there are differences, one of which entails the strength of ocular dominance signals, which appear weaker in the younger animals and which increase steadily with age. Another, more striking, difference concerns the widths of ocular dominance columns, which increase by 20% during the first 3 months of life. Since the cortical surface area increases by a comparable amount, during the same time, this 20% expansion implies that growth occurs anisotropically, perpendicular to the ocular dominance columns, as the cortical surface expands. Since the observed patterns of orientation preference expand more slowly, at approximately half this rate, these results also imply that ocular dominance and orientation patterns change their relationship, and may even drift past one another, as young animals mature.
KW - Development
KW - Ocular dominance
KW - Orientation selectivity
KW - Primate striate cortex
UR - http://www.scopus.com/inward/record.url?scp=0029294666&partnerID=8YFLogxK
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U2 - 10.1017/S0952523800008476
DO - 10.1017/S0952523800008476
M3 - Article
C2 - 7654611
AN - SCOPUS:0029294666
SN - 0952-5238
VL - 12
SP - 589
EP - 603
JO - Visual neuroscience
JF - Visual neuroscience
IS - 3
ER -