Measurement of auditory evoked magnetic field of mice with high spatial resolution

In this paper, a high resolution SQUID system was used for animal experiments. The auditory evoked magnetic fields of three adult mice were measured. Tone bursts of 2 kHz with 10 ms duration was used as the auditory stimuli. The stimuli were presented to the right ear of the mouse through a plastic tube. Magnetic signals were filtered from 1 to 100 Hz and averaged more than 5000 times. The peak of the magnetic fields appeared at the latency about 20 ms and the large peak appeared at the latency 80 ms. The study showed that it is possible to measure the mice magnetoencephalogaphy (MEG) with adequate spatial resolution. Animal MEG measurement may contribute to the further understanding of the physiological basis of the MEG.