Alexander Poplawsky1, Raymond Dingledine2, Xiaoping Hu3
1Neuroscience, Emory University, Atlanta, GA, United States; 2Pharmacology, Emory University, Atlanta, GA, United States; 3Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, United States
Direct detection of axonal neural magnetic fields (NMFs) by magnetic resonance imaging has met with conflicting evidence. The objective of this study is to demonstrate the temporal signature of axonal NMFs in the free induction decay (FID), which provides the temporal resolution required to capture an axonal event. Simultaneous electrophysiology is used to time-lock earthworm action potentials to FID acquisition. Our data demonstrates clear evidence of a phase change that temporally corresponds to the electrophysiologically recorded action potential and is consistent with theoretical predictions.