scholarly journals In vivo measurement of axon diameter distribution in the corpus callosum of rat brain

Brain ◽  
2009 ◽  
Vol 132 (5) ◽  
pp. 1210-1220 ◽  
Author(s):  
Daniel Barazany ◽  
Peter J. Basser ◽  
Yaniv Assaf
Keyword(s):  
Corpus Callosum ◽  
Rat Brain ◽  
Diameter Distribution ◽  
Axon Diameter ◽  
In Vivo Measurement

scholarly journals Modelling conduction delays in the corpus callosum using MRI-measured g-ratio

2018 ◽  
Author(s):  
S. Berman ◽  
S. Filo ◽  
A. A. Mezer
Keyword(s):  
White Matter ◽  
Corpus Callosum ◽  
Quantitative Mri ◽  
Biophysical Model ◽  
Diameter Distribution ◽  
Conduction Delay ◽  
Axon Diameter ◽  
Healthy Human ◽  
G Ratio

AbstractConduction of action potentials along myelinated axons is affected by their structural features, such as the axonal g-ratio, the ratio between the inner and outer diameters of the myelin sheath surrounding the axon. The effect of g-ratio variance on conduction properties has been quantitatively evaluated using single-axon models. It has recently become possible to estimate a g-ratio weighted measurement in vivo using quantitative MRI. Nevertheless, it is still unclear whether the variance in the g-ratio in the healthy human brain leads to significant differences in conduction velocity. In this work we tested whether the g-ratio MRI measurement can be used to predict conduction delays in the corpus callosum.We present a novel framework in which the structural properties of fibers (i.e. length and g-ratio, measured using MRI), are incorporated in a biophysical model of axon conduction, to predict conduction delays of long-range white matter fibers. We applied this framework to the corpus callosum, and found conduction delay estimates that are compatible with previously estimated values of conduction delays. We account for the variance in the velocity given the axon diameter distribution in the splenium, mid-body and genu, to further compare the fibers within the corpus callosum.Conduction delays have been suggested to increase with age. Therefore, we investigated whether there are differences in the g-ratio and the fiber length between young and old adults, and whether this leads to a difference in conduction speed and delays. We found small but significant differences between the predicted delays of the two groups in the motor fibers of the corpus callosum. We also found that the motor fibers of the corpus callosum have the fastest conduction estimates. Using the axon diameter distributions, we found that the occipital fibers have the slowest estimations, while the frontal and motor fiber tracts have similar estimates.Our study provides a framework for predicting conduction latencies in vivo. The framework could have major implications for future studies of white matter diseases and large range network computations. Our results highlight the need for improving additional in vivo measurements of white matter microstructure.

Characterization of amperometry for in vivo measurement of dopamine dynamics in the rat brain

Talanta ◽  
1994 ◽  
Vol 41 (6) ◽  
pp. 865-874 ◽  
Author(s):  
Kirk T. Kawagoe ◽  
R.Mark Wightman
Keyword(s):  
Rat Brain ◽  
In Vivo Measurement

In vivo measurement of [18f]fluorodeoxyglucose rate constants in rat brain by external coincidence counting

Neuroscience ◽  
1987 ◽  
Vol 22 (2) ◽  
pp. 593-599 ◽  
Author(s):  
C. Redies ◽  
H. Matsuda ◽  
M. Diksic ◽  
E. Meyer ◽  
Y.L. Yamamoto
Keyword(s):  
Rat Brain ◽  
Rate Constants ◽  
Coincidence Counting ◽  
In Vivo Measurement ◽  
18F Fluorodeoxyglucose

Sigma receptors mediate potent neuroprotection in vivo and inhibit neuronal depolarisation and swelling in rat brain slices

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S468-S468
Author(s):  
Jennifer K Callaway ◽  
Christine Molnar ◽  
Song T Yao ◽  
Bevyn Jarrott ◽  
R David Andrew
Keyword(s):  
Rat Brain ◽  
Brain Slices ◽  
Sigma Receptors

In vivo diffusion tensor imaging of the neonatal rat brain development

2013 ◽  
Vol 44 (S 01) ◽  
Author(s):  
M Breu ◽  
D Reisinger ◽  
D Wu ◽  
Y Zhang ◽  
A Fatemi ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Brain Development ◽  
Rat Brain ◽  
Diffusion Tensor ◽  
Neonatal Rat ◽  
Neonatal Rat Brain
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