Adult, male Sprague-Dawley rats of the Charles River cesarean delivered (CD) strain were used in the study.Animals were kept under controlled environmental conditions (temperature 22oC, relative humidity 45-55%, 12-h light/dark cycle) and housed individually with NIH-41 Irradiated Rodent Diet (Harlan Teklad, Madison, WI) chow and tap water supplied ad libitum. Bipolar stainless steel electrodes were implanted 3 mm laterally from the sagittal fissure, 1 and 4 mm posterior to the bregma. They were referenced to a ground electrode placed in the dorsal neck. The ECoG was recorded via a tether and swivel system at least one week after implantation. During recording, the animals remained in a microdialysis bowl placed inside a Faraday cage. Amplified signals were rectified to pass frequencies of 1-40 Hz and processed with Lab View software (National Instruments, Austin, TX). The power spectra obtained by use of FFT were divided into 1.25-4.5 Hz (delta), 4.75—6.75 (theta), 7.00-9.50 Hz (alpha1), 9.75-12.50 Hz (alpha2), 12.75-18.5 Hz (beta1), and 18.75-35.00 Hz (beta2) frequency bands [2]. Following the intraperitoneal (i.p.) saline injection and 30-min baseline recording, rats were treated i.p. with compounds of interest and recording continued for the next 60 -120 min.
