抄録
We measured the auditory and visual evoked magnetic fields of rats, using a high-resolution dc-SQUID magnetometer with 12 channels. The specifications of our system are as follows: pick-up coils 5 mm in diameter located on a 7.5-mm grid, 15-mm base-line of the gradiometer, one-turn pick-up coil, 5-mm distance between the pick-up coil and the outside surface of the dewar, and 100-fT/√Hz field resolution. The rats, responses to auditory and visual stimulation were observed. Auditory signals appeared at 34 ms, and the intensities of the magnetic fields were approximately 500 fT. Visual signals appeared at 60 ms, and their intensities were about 1 pT. Consequently, the system used in this study is useful for physiological studies of small animals.
