CaMKIIα‐tTA/A53T α‐syn dTg mice replicate the following key features of DLB and PDD: (1) α‐synuclein pathology 32; (2) cholinergic deficit in the cerebral cortex (Figure 6A); (3) reduction in pre‐ and postsynaptic proteins (Figure 6B and C); (4) cerebral and hippocampal atrophy 32; (5) memory deficits (Figure 7)32; and (6) amelioration of memory deficits by donepezil (Figure 7). Here, CAMK2A is linked to hippocampal atrophy.