Answer would be more helpful if you can provide me any Data (or) article which majorly describes about the predominance of different brain waves in normal as well as in diseased rats.
This article may assist you:Alteration of brain monoamines & EEG wave pattern in rat model of Alzheimer’s disease & protection by Moringa oleifera, R. Ganguly & D. Guha Indian J Med Res 128, December 2008, pp 744-751. All the best.