The loss of dopaminergic neurons and the resultant motor impairment are hallmarks of Parkinson's disease. The SHSY5Y cell line is a model of dopaminergic neurons, and allows for the study of dopaminergic neuronal injury. Previous studies have revealed changes in Ether a gogo 1 (Eag1) potassium channel expression during p53-induced SHSY5Y apoptosis, and the regulatory involvement of microRNA34a (miR34a) was demonstrated. In the present study, the involvement of Eag1 and miR34a in rotenoneinduced SHSY5Y cell injury was investigated. Rotenone is a neurotoxin, which is often used to generate models of Parkinson's disease, since it causes the death of nigrostriatal neurons by inducing intracellular aggregation of alpha synuclein and ubiquitin. In the present study, rotenone resulted in a dosedependent decrease in cell viability, as revealed by 3(4,5dimethylthiazol2yl)2,5diphenyltetrazolium bromide (MTT) and trypan blue cell counting assays. In addition, Eag1 was demonstrated to be constitutively expressed by SHSY5Y cells, and involved in cell viability. Suppression of Eag1 with astemizole resulted in a dosedependent decrease in cell viability, as revealed by MTT assay. Astemizole also enhanced the severity of rotenoneinduced injury in SHSY5Y cells. RNA interference against Eag1, using synthetic small interfering RNAs (siRNAs), corroborated this finding, as siRNAs potentiated rotenoneinduced injury. Eag1targeted siRNAs (kv10.13 or EAG1hum_287) resulted in a statistically significant 16.423.5% increase in vulnerability to rotenone. An increased number of apoptotic nuclei were observed in cells transfected with EAG1hum_287. Notably, this siRNA intensified rotenoneinduced apoptosis, as revealed by an increase in caspase 3/7 activity. Conversely, a miR34a inhibitor was demonstrated to exert neuroprotective effects. The viability of cells exposed to rotenone for 24 or 48 h and treated with miR34a inhibitor was restored by 8.48.8%. In conclusion, Eag1 potassium channels and miR34a are involved in the response to rotenone-induced injury in SHSY5Y cells. The neuroprotective effect of mir34a inhibitors merits further investigations in animal models of Parkinson's disease.