Time course and duration of changes in Kv7.2 and Kv11.1 mRNA expression in the hippocampus and piriform cortex following electroconvulsive stimulations

BackgroundA minimum of six electroconvulsive therapy (ECT) treatments has to be delivered to achieve sustained improvement in major depression. However, the mechanisms of the therapeutic actions of ECT are still debated.ObjectiveWe aimed to study the time course and duration of increased Kv7.2 and Kv11.1 mRNA expression in the hippocampus and piriform cortex (Pir) after electroconvulsive stimulation (ECS).MethodsAdult male Sprague-Dawley rats received three ECS per week over 1, 2, or 3 weeks and were decapitated 3 days after the last stimulus. Additional groups of rats receiving nine ECS were sacrificed 7 or 28 days after the last ECS. In situ hybridization was used to measure Kv channel mRNA expression after ECS.ResultsKv7.2 mRNA was increased in the hippocampus and Pir 3 days after both six and nine, but not after three ECS. This was also seen for Kv11.1 mRNA in Pir. These changes lasted for at least 7 days.ConclusionsThese results indicate that the changes in Kv7.2 and Kv11.1 channels may contribute to the therapeutic effect of ECT. However, further research needs to be undertaken in this area to extend these findings.