TY - JOUR
T1 - Geometry and structural plasticity of synaptic connectivity
AU - Stepanyants, Armen
AU - Hof, Patrick R.
AU - Chklovskii, Dmitri B.
N1 - Funding Information:
This work was supported by the Lita Annenberg Hazen Foundation and the David and Lucile Packard Foundation at Cold Spring Harbor Laboratory, and by the Howard Hughes Medical Institute and NIH Grants AG05138 and MH58911 at Mount Sinai School of Medicine. P.R.H. thanks Dr. P.R. Rapp for providing some of the monkey materials used in this study, H. Duan and B. Wicinski for cell loading, and W.G.M. Janssen for expert technical assistance. We are grateful to C. Brody, H. Cline, A. Koulakov, S. Macknik, R. Malinow, P. Mitra, T. Oertner, G. Shepherd, Jr., K. Svoboda, and N. Swindale for carefully reading various versions of the manuscript and making helpful comments.
PY - 2002/4/11
Y1 - 2002/4/11
N2 - Changes in synaptic connectivity patterns through the formation and elimination of dendritic spines may contribute to structural plasticity in the brain. We characterize this contribution quantitatively by estimating the number of different synaptic connectivity patterns attainable without major arbor remodeling. This number depends on the ratio of the synapses on a dendrite to the axons that pass within a spine length of that dendrite. We call this ratio the filling fraction and calculate it from geometrical analysis and anatomical data. The filling fraction is 0.26 in mouse neocortex, 0.22-0.34 in rat hippocampus. In the macaque visual cortex, the filling fraction increases by a factor of 1.6-1.8 from area V1 to areas V2, V4, and 7a. Since the filling fraction is much smaller than 1, spine remodeling can make a large contribution to structural plasticity.
AB - Changes in synaptic connectivity patterns through the formation and elimination of dendritic spines may contribute to structural plasticity in the brain. We characterize this contribution quantitatively by estimating the number of different synaptic connectivity patterns attainable without major arbor remodeling. This number depends on the ratio of the synapses on a dendrite to the axons that pass within a spine length of that dendrite. We call this ratio the filling fraction and calculate it from geometrical analysis and anatomical data. The filling fraction is 0.26 in mouse neocortex, 0.22-0.34 in rat hippocampus. In the macaque visual cortex, the filling fraction increases by a factor of 1.6-1.8 from area V1 to areas V2, V4, and 7a. Since the filling fraction is much smaller than 1, spine remodeling can make a large contribution to structural plasticity.
UR - http://www.scopus.com/inward/record.url?scp=0037061689&partnerID=8YFLogxK
U2 - 10.1016/S0896-6273(02)00652-9
DO - 10.1016/S0896-6273(02)00652-9
M3 - Article
C2 - 11970869
AN - SCOPUS:0037061689
SN - 0896-6273
VL - 34
SP - 275
EP - 288
JO - Neuron
JF - Neuron
IS - 2
ER -