PT  - JOURNAL ARTICLE
AU  - Laxmi Kumar Parajuli
AU  - Hidetoshi Urakubo
AU  - Ai Takahashi-Nakazato
AU  - Roberto Ogelman
AU  - Hirohide Iwasaki
AU  - Masato Koike
AU  - Hyung-Bae Kwon
AU  - Shin Ishii
AU  - Won Chan Oh
AU  - Yugo Fukazawa
AU  - Shigeo Okabe
TI  - Geometry and the Organizational Principle of Spine Synapses along a Dendrite
AID  - 10.1523/ENEURO.0248-20.2020
DP  - 2020 Nov 01
TA  - eneuro
PG  - ENEURO.0248-20.2020
VI  - 7
IP  - 6
4099  - http://www.eneuro.org/content/7/6/ENEURO.0248-20.2020.short
4100  - http://www.eneuro.org/content/7/6/ENEURO.0248-20.2020.full
SO  - eNeuro2020 Nov 01; 7
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 uncaging 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.