For example, pharmacological activation of cGMP via phosphodiesterase (PDE) inhibition improves synaptic plasticity and memory in mouse models of AD (Gulisano et al. 2018), while enhanced de novo pyrimidine synthesis has been shown to improve synaptic function and protect against cognitive decline in aging and AD animal models (Pesini et al. 2019). This evidence concerns the gene ALDH7A1 and Alzheimer disease.