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EEG SPECTRA, BEHAVIORAL STATES AND MOTOR ACTIVITY IN RATS EXPOSED TO ACETYLCHOLINESTERASE INHIBITOR CHLORPYRIFOS.
Citation:
Timofeeva, O. A. AND C J. Gordon. EEG SPECTRA, BEHAVIORAL STATES AND MOTOR ACTIVITY IN RATS EXPOSED TO ACETYLCHOLINESTERASE INHIBITOR CHLORPYRIFOS. Society for Neuroscience, San Diego, CA, 11/10-15/2001.
Description:
Exposure to organophosphate pesticides (OP) has been associated with sleep disorders: insomnia and ?excessive dreaming'. However neuronal mechanisms of these effects have not been analyzed. OP inhibit acetylcholinesterase activity leading to a hyperativity of the brain cholinergic systems, that are involved in sleep regulation. In the present work we studied alterations in the EEG, behavioral states, motor activity and core temperature in rats orally administered with 10 or 40 mg/kg of chlorpyrifos (CHP) an OP pesticide. We recorded occipital EEG, motor activity and core temperature with telemetric transmitters (Data Sciences Inc.). Behavioral sleep-wake states were visually scored. Both doses of CHP produced significant alterations of the EEG (decrease in power of sigma/beta and increase in slow theta and fast gamma bands) characteristic for arousal. EEG alterations were consistent with behavioral changes such as a dramatic increase in wakefulness and a decrease in sleep. Among waking activities, waking immobility was prevalent We did not detect any overt signs of CHP toxicity, such as tremor, abnormal posture or gait. This suggests that reduced motor activity can be result of central affects of CHP (such as activation of cholinergic motor inhibitory system) rather than peripheral (such as disturbance in neuromascular function). Changes in the EEG and behavior occurred independently of the decrease in core temperature. Most of the observed effects were dose-dependent.