However, it is unclear whether restoring catecholaminergic transmission in the terminals from the LC may alleviate the spatial memory deficits associated with AD.<h4>Objectives</h4>This study aims to investigate the effects of optogenetic stimulation of LC catecholaminergic projections on alleviating spatial memory and synaptic plasticity deficits associated with AD.<h4>Methods</h4>We conducted experiments using a 12-month-old 3xTgAD mouse model (AD-TH) that expresses Cre recombinase under the control of the tyrosine hydroxylase (TH) gene. This evidence concerns the gene TH and Alzheimer disease.