RT Journal Article
SR Electronic
T1 Geometry and the Organizational Principle of Spine Synapses along a Dendrite
JF eneuro
JO eNeuro
FD Society for Neuroscience
SP ENEURO.0248-20.2020
DO 10.1523/ENEURO.0248-20.2020
VO 7
IS 6
A1 Laxmi Kumar Parajuli
A1 Hidetoshi Urakubo
A1 Ai Takahashi-Nakazato
A1 Roberto Ogelman
A1 Hirohide Iwasaki
A1 Masato Koike
A1 Hyung-Bae Kwon
A1 Shin Ishii
A1 Won Chan Oh
A1 Yugo Fukazawa
A1 Shigeo Okabe
YR 2020
UL http://www.eneuro.org/content/7/6/ENEURO.0248-20.2020.abstract
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.