Rotenone impairs hippocampal neuronal activity in a rat model of Parkinson's disease.

Parkinson's disease (PD) is the most common neurodegenerative disease of unknown etiology and characterized by motor symptoms of tremor, rigidity, bradykinesia, and postural instability. Interactions between the dopaminergic systems and the hippocampus in synaptic plasticity and behavior are found. The rotenone-induced animal model is commonly used in research studies involved in PD. Administration of rotenone causes alterations of electrical neuronal activity. Rotenone (2.5 mg/kg/day) was administered intraperitoneally for 21 days to adult rats, and rotenone effects on rearing activity and electrophysiology were examined. Dose-dependent reduction of evoked neural activity and a reduction in firing strength were found in the hippocampus. Behaviorally, Rotenone rats showed a more consistent decrease in rearing across the 3 weeks, compared with animals in the control group. Thus, rotenone causes changes in hippocampal electrical activity and behavioral changes.