Welcome to Free Medical video : Medical videos!
Most Popular
Members
Username:

Password:

 Remember me
You have 21 more plays before you must register
Register
Statistics
Total Files: 642
views Today: 363
Overall views: 3,477,381
Total Members: 16,150
Users online: 8 (0 members, 8 guests)
Top Players
kareem (2,545 plays)
erdstowermilla (1,533 plays)
Dr.Hady (1,491 plays)
hashimato (1,056 plays)
euschermail (1,041 plays)
Search

Advertisment
 
File Info
Title: A journey through the brain's wiring
Description: he complex circuitry interconnecting different areas in the brain, known collectively as white matter, is composed of millions of axons organized into fascicles and bundles. Upon macroscopic examination of sections of the brain, it is difficult to discern the orientation of the fibers. The same is true for conventional imaging modalities. However, recent advancements in magnetic resonance imaging (MRI) make such task possible in a live subject. By sensitizing an otherwise typical MRI sequence to the diffusion of water molecules it is possible to measure their diffusion coefficient in a given direction1. Normally, the axonal membrane and myelin sheaths pose barriers to the movement of water molecules and, thus, they diffuse preferentially along the axon2. Therefore, the direction of white matter bundles can be elucidated by determining the principal diffusivity of water. The three-dimensional representation of the diffusion coefficient can be given by a tensor and its mathematical decomposition provides the direction of the tracts3; this MRI technique is known as diffusion tensor imaging (DTI). By connecting the information acquired with DTI, three-dimensional depictions of white matter fascicles are obtained4. The virtual dissection of white matter bundles is rapidly becoming a valuable tool in clinical research. Our journey begins with a transverse section of tightly packed axons as seen through light microscopy. Although represented as a two-dimensional "slice", we see that these axons in fact resemble tubes. A simulation of water molecules diffusing randomly inside the axons demonstrates how the membranes and myelin hinder their movement across them and shows the preferred diffusion direction --along the axons. The tracts depicted through DTI slowly blend in and we ride along with them. As we zoom out even more, we realize that it is a portion of the corpus callosum connecting the two sides of the brain we were traveling on and the great difference in relative scale of the individual axons becomes evident. The surface of the brain is then shown, as well as the rest of the white matter bundles--a big, apparently chaotic tangle of wires. Finally, the skin covers the brain. With the exception of the simulated water molecules, all the data presented in the animation is obtained through microscopy and MRI. Computer algorithms for the extraction of the cerebral structures and a custom-built graphics engine make our journey through the brain's anatomy possible in a living person. Micrograph courtesy of Dr. Christian Beaulieu, University of Alberta. Music by Mario Mattioli. References: 1. Stejskal, E.O., et al., J. Chem. Phys., 1965. 42: 2. Beaulieu, C., NMR Biomed., 2002. 15:435-55. 3. Basser, P.J., et al., J. Magn. Reson. B, 1994. 103:247-54. 4. Mori, S., et al., NMR Biomed., 2002. 15:468-80.
views: 4,477 times
Rating: 3
Rate
Tell a Friend
Free Medical video : Medical videos > Animations > A journey through the brain's wiring

Share |

Related health videos:
Digestive System animation Digestive System animation
The Digestive System animation
(Played: 11,179 times)
Traumatic Brain Injury Traumatic Brain Injury
n correlation with some of the nation's leading medical experts and trial att...
(Played: 3,036 times)
Prostatectomy Animation Prostatectomy Animation
Robotic Prostatectomy Prostate Cancer Surgery Tewari Weill Cornell Urology
(Played: 7,634 times)
 Evolution Human Genome Evolution Human Genome
Evolution Human Genome
(Played: 3,302 times)
Intubation Intubation
this is a sample from an innovative training system called foundationskills.n...
(Played: 4,028 times)
Comments:
Please login or register to leave a comment.
Add this file to your website:
Top search queries: childbirth video - free medical video - Medical videos - Gamma Knife Treatment - Renal Dialysis - Catheter insertion - surgery Video -  methothelioma  - gynecology video -Autopsy videos- Medical videos - normal birth - Mesothelioma new - Autopsy video - catheter insertion - clinical examination - pediatric exam video - laparoscopic hysterectomy video - Real autopsy

All videos copyright © to their respective owner s. All rights reserved.