DLG4 and Alzheimer disease: Only one related study has shown that unilateral ILN DBS treatment can improve spatial learning and memory deficits in AD rat models injected with β-amyloid (Aβ), reduce the expression of postsynaptic density protein 95 (PSD-95) in the mPFC and hippocampus, and maintain dendritic spine density (Tsai et al., 2020).