Correlation between electrocorticographic and motor phenomena in lindane-induced experimental epilepsy in rats

We report a study on the relation between open-field behavior and electroencephalographic (EEG) changes during lindane-induced seizures in 2-month-old adult male Wistar rats. For chronic EEG recordings and power spectra analysis, 3 electrodes were implanted into the skull. Three groups of animals, (i) saline-injected control (n = 6), (ii) DMSO-treated (n = 6), and (iii) lindane intraperitoneally administered: L(4) (4 mg/kg, n = 10), L(6) (6 mg/kg, n = 11), and L(8) (8 mg/kg, n = 11), were observed for 30 min for the occurrence of convulsive behavior. It was assessed by incidence of motor seizures, and seizure severity grade was determined by a descriptive rating scale (0, no response; 1, head nodding, lower jaw twitching; 2, myoclonic body jerks, bilateral forelimb clonus with full rearing; 3, progression to generalized clonic convulsions followed by tonic extension of fore and hind limbs and tail; 4, status epilepticus). EEG signal and spectral analyses were suitable to describe the dynamics of complex behavioral responses. Incidence and severity of epileptic manifestations, recorded as high voltage spike-wave complexes, polyspikes, sleep-like patterns in EEG, and power spectra changes, were greater in lindane-treated groups in a dose-dependent manner compared with control or DMSO-treated groups. Our results suggest good correlation between lindane-induced epileptiform activity and behavioral changes.