B. AMUZESCU*^#, G. COCINA**, S. FLORICA***

*Deptartment of Biophysics & Physiology, Faculty of Biology, University of Bucharest, 91–95, Splaiul Independenței, Bucharest 050095, Romania
**Smart Systems Consulting SRL, P.O. Box 2-263, Bucharest 014730 Romania
***Deptartment of Geology, Faculty of Biology & Geology, ”Babeș-Bolyai” University, 1, M. Kogalniceanu St, Cluj 400294 Romania

We describe design, construction, testing, and use of an advanced electroencephalography (EEG) system for experimental surface recordings on small laboratory animals. Signals are collected with a miniature electrode array containing 8 longitudinal bipolar leads and a ground electrode, preamplified 2000-fold with headstage miniature circuits based on low-offset zero-drift op-amps in an instrumentation amplifier design, then filtered via 6th order Chebyshev active filters with passing band 0–35 Hz, sampled at 1 KHz and recorded with standard electrophysiology equipment. We determined the transfer functions (gain and phase shift) for different preamplifier circuits and the filters. A real-life test of the equipment was performed on an adult male Wistar rat weighing 310 g following headstage placement under dietylether anesthesia. The recording had a typical shape; its Fourier transform indicated higher spectral power density in the δ and θ range of frequencies (1–7 Hz), as well as β rhythm.

Corresponding author’s e-mail: bogdan@biologie.kappa.ro

Full text: PDF