TY - JOUR
T1 - Geometry and the organizational principle of spine synapses along a dendrite
AU - Parajuli, Laxmi Kumar
AU - Urakubo, Hidetoshi
AU - Takahashi-Nakazato, Ai
AU - Ogelman, Roberto
AU - Iwasaki, Hirohide
AU - Koike, Masato
AU - Kwon, Hyung Bae
AU - Ishii, Shin
AU - Oh, Won Chan
AU - Fukazawa, Yugo
AU - Okabe, Shigeo
N1 - Publisher Copyright:
© 2020 Parajuli et al.
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Precise information on synapse organization in a dendrite is crucial to understanding the mechanisms underlying voltage integration and the variability in the strength of synaptic inputs across dendrites of different complex morphologies. Here, we used focused ion beam/scanning electron microscope (FIB/SEM) to image the dendritic spines of mice in the hippocampal CA1 region, CA3 region, somatosensory cortex, striatum, and cerebellum (CB). Our results show that the spine geometry and dimensions differ across neuronal cell types. Despite this difference, dendritic spines were organized in an orchestrated manner such that the postsynaptic density (PSD) area per unit length of dendrite scaled positively with the dendritic diameter in CA1 proximal stratum radiatum (PSR), cortex, and CB. The ratio of the PSD area to neck length was kept relatively uniform across dendrites of different diameters in CA1 PSR. Computer simulation suggests that a similar level of synaptic strength across different dendrites in CA1 PSR enables the effective transfer of synaptic inputs from the dendrites toward soma. Excitatory postsynaptic potentials (EPSPs), evoked at single spines by glutamate un-caging and recorded at the soma, show that the neck length is more influential than head width in regulating the EPSP magnitude at the soma. Our study describes thorough morphologic features and the organizational principles of dendritic spines in different brain regions.
AB - Precise information on synapse organization in a dendrite is crucial to understanding the mechanisms underlying voltage integration and the variability in the strength of synaptic inputs across dendrites of different complex morphologies. Here, we used focused ion beam/scanning electron microscope (FIB/SEM) to image the dendritic spines of mice in the hippocampal CA1 region, CA3 region, somatosensory cortex, striatum, and cerebellum (CB). Our results show that the spine geometry and dimensions differ across neuronal cell types. Despite this difference, dendritic spines were organized in an orchestrated manner such that the postsynaptic density (PSD) area per unit length of dendrite scaled positively with the dendritic diameter in CA1 proximal stratum radiatum (PSR), cortex, and CB. The ratio of the PSD area to neck length was kept relatively uniform across dendrites of different diameters in CA1 PSR. Computer simulation suggests that a similar level of synaptic strength across different dendrites in CA1 PSR enables the effective transfer of synaptic inputs from the dendrites toward soma. Excitatory postsynaptic potentials (EPSPs), evoked at single spines by glutamate un-caging and recorded at the soma, show that the neck length is more influential than head width in regulating the EPSP magnitude at the soma. Our study describes thorough morphologic features and the organizational principles of dendritic spines in different brain regions.
KW - Dendritic spine
KW - Electron microscopy
KW - FIB/SEM
KW - Glutamate uncaging
KW - Postsynaptic density
KW - Simulation
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U2 - 10.1523/ENEURO.0248-20.2020
DO - 10.1523/ENEURO.0248-20.2020
M3 - Article
C2 - 33109633
AN - SCOPUS:85099073536
SN - 2373-2822
VL - 7
JO - eNeuro
JF - eNeuro
IS - 6
M1 - ENEURO.0248-20.2020
ER -