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Updated: Oct 5, 2026
Simultaneous Intracellular Recording of a Lumbar Motoneuron and the Force Produced by its Motor Unit in the Adult Mouse In vivo
Published on: December 5, 2012
Tracing of proximal lumbosacral nerve conduction--a comparison of simultaneous magneto- and electroneurography
B M Mackert1, M Burghoff, L H Hiss
1Neurophysics Group, Department of Neurology, Klinikum Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 30, 12203, Berlin, Germany. macbm@zedat.fu-berlin.de
Objective:
The reconstruction of nerve impulse conduction along proximal lumbosacral plexus and nerve roots is compared using simultaneous magneto- and electroneurography.
Methods:
In 3 healthy subjects the left tibial nerve was electrostimulated at the ankle. Evoked magnetic fields and electric surface potentials were measured simultaneously over the lumbosacral spine using a multichannel SQUID-detector with a planar measuring area and 25 surface electrodes covering a comparable area centered around L4. Based on either magnetic field or electric potential maps the depolarization front of the evoked compound action currents (CAC) was spatio-temporally reconstructed using a simple equivalent current dipole model in a half-space volume conductor.
Results:
The mean signal-to-noise ratio in the magnetic (electric) recordings was around 4 (8). Yet, the localization quality for the propagating CAC was lower for electric than magnetic recordings. The local nerve conduction velocity was around 47 m/s (calculated from magnetic data), but fluctuated unphysiologically for electric data.
Conclusion:
In comparison to electroneurography, an anatomically reasonable localization of evoked compound action currents propagating in lumbosacral roots can be obtained by magnetoneurography.
