Effect of pesticides on central and peripheral nervous system function in rats.

The neurobehavioral toxicity of three organophosphate pesticides, sumithion, dimefox and trichlorphon, was evaluated in rats using measures of open field activity, rotorod performance, conditioned escape from shock, and nerve conduction velocity. These measures were correlated with blood and brain cholinesterase level determinations. All three chemicals disrupted behavior ranging from transient disruptions accompanied by alterations in nerve conduction to disruption throughout the exposure. Even in the case of prolonged behavioral disruption, however, some recovery of performance occurred. Cholinesterase in both blood and brain decreased with initial dosing and remained low with continued dosing regardless of changes in the behavioral measures. The results are discussed in terms of the necessity of using mammalian behavioral tests to determine the toxicity of organophosphorous compounds in order to safeguard the health of the human population.