Magnetic field effect of neuronal currents on MRI: A snail ganglia study
Lee S, Park T, Park J, Cho M, Han B, Lee S
Kyung Hee University
We observed the response of magnetic resonance signal to neuronal activity in the dissected snail ganglia to investigate faster responding components than the BOLD component. To activate the snail ganglia in synchronization with magnetic resonance signal measurement, we applied 30 Hz electrical stimulation with the pulse width of 2 s to the ganglia just before the 90 degree RF pulse. The magnetic resonance signal intensity, measured with the volume selection pulse sequence in a 3.0 T MRI, decreased about 2.971.10 % when the ganglia were activated by the electrical stimulation. We think that the signal decrease is partly due to the magnetic field produced by the neuronal current and partly to the Lorentz force exerted on the neurons when they were firing.