CAMK2A and epilepsy: To investigate the role of STN excitatory neurons (most of them being glutamatergic neurons) in seizures of motor epilepsy, we used an optogenetic approach to selectively stimulate Channelrhodopsin 2 (ChR2)-expressing excitatory neurons in the STN of CamKIIα-ChR2-eYFP mice (Figures 2A,B).