Rapid axonal sprouting and pruning accompany functional reorganization in primary visual cortex.
The functional architecture of adult cerebral cortex retains a capacity for experience-dependent change. This is seen following focal binocular lesions, which induce rapid changes in receptive field size and position. To follow the dynamics of the circuitry underlying these changes, we imaged the intrinsic long-range horizontal connections within the lesion projection zone (LPZ) in adult macaque primary visual cortex. To image the same axons over time, we combined viral vector-mediated EGFP transfer and two-photon microscopy. The lesion triggered, within the first week, an approximately 2-fold outgrowth of axons toward the center of the LPZ. Over the subsequent month, axonal density declined due to a parallel process of pruning and sprouting but maintained a net increase relative to prelesion levels. The rate of turnover of axonal boutons also increased. The axonal restructuring recapitulates the pattern of exuberance and pruning seen in early development and correlates well with the functional changes following retinal lesions.
Yamahachi
Homare
H
The Rockefeller University, New York, NY 10065, USA.
Marik
Sally A
SA
McManus
Justin N J
JN
Denk
Winfried
W
Gilbert
Charles D
CD
D000818:Animals; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D001931:Brain Mapping; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008252:Macaca fascicularis; D008856:Microscopy, Fluorescence / Q000379:methods; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000166:cytology*; D017729:Presynaptic Terminals / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D012160:Retina / Q000293:injuries; D018709:Statistics, Nonparametric; D013997:Time Factors; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology
C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins