Abstract
A wireless recording system was developed to examine the electroencephalogram (EEG) activity in unrestrained piglets. The equipment was composed of a miniature preamplifier and an FM transmitter, and was driven by batteries. The signal from the telemetry equipment was detected by antennas on the ceiling of the Faraday chamber, and then filtered and, magnified with a conventional amplifier. Under general anesthesia, silver-silver chloride electrodes were implanted onto the dura matter and were fixed by dental cement with the preamplifier and transmitter on the surface of the skull of the male Landrace piglets. Stainless-steel wire electrodes were sewn into the upper eye-lids to detect their movement. After the piglets recovered from surgery, the EEG and eye-lid movement were recorded in the unrestrained condition while they were lying down in the daytime. Off-line, power spectral analysis of the EEG activity using a Fast Fourier Transformation algorithm indicated that slow waves with frequencies from 0.5 to 3.9 Hz were often dominant in the EEGs of these animals without the eye-lid movements. In contrast, the slow waves diminished when eye-lid movements were recorded. [Jpn J Physiol 54 Suppl:S205 (2004)]
