ACHE and Dravet syndrome: AChE activity levels per EV in the brains of DS patients were not different from 2N controls (DS/2N ratio = 0.96) (Fig. 1f), similar to the levels of AChE per EV in the brains of 3- (Ts2/2N ratio = 1.00), 8- (Ts2/2N ratio = 0.95), 12- (Ts2/2N ratio = 1.05) and 24-month-old (Ts2/2N ratio = 1.06) Ts2 mice compared to age-matched 2N controls (Fig. 1g).