Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: roger858 on 19/02/2016 05:19:03

Title: Does the biot-savart law explain the magnetic grid pattern seen in the brain?
Post by: roger858 on 19/02/2016 05:19:03

I was interested anyone's opinion on whether the grid pattern seen in diffusion tensor imaging of the brain could be physics based. The biot-savart law, which states an electric current along a rod generates a cylindrical magnetic field with the rod being in the center  [ Invalid Attachment ] .  Could several brain fibers in parallel create a magnetic field capable of starting brain electrical current in a perpendicular direction as can be seen in the dti imaging  [ Invalid Attachment ] ?

Title: Re: can the biot- savart law explain grid pattern seen in brain mri?
Post by: evan_au on 19/02/2016 08:39:02

It is a bit hard to see 3D information in a small 2D photo.

Is this a diffusion MRI, tracing the path of nerve axons?
http://en.wikipedia.org/wiki/Diffusion_MRI#Introduction

The grid pattern appears to be bundles of nerves traveling in different directions, forming a grid pattern?

Please explain the significance of the different arrows.

Note that the pattern of current flow in a neuron is axially symmetric, with ions flowing radially in and out of the axon. Not much current flows along the axon (as it would through a copper wire carrying a DC current). With this pattern of ion flow, I would be surprised to see currents jumping between adjacent bundles of nerves (apart from at synapses, where it is supposed to do this...).