PROJECT SUMMARY / ABSTRACT Alzheimer’s disease (AD) is the most common cause of dementia, affecting 3–11% of the United States elderly. On the other hand, the estimated incidence of prenatal alcohol exposure (PAE)-induced mental disability or disease is 10 per 1000 live births. Although theoretically PAE-induced mental diseases are preventable, the prevalence of PAE has been reported to be as high as 10%-16.3%. Among a broad spectrum of PAE and AD- associated symptoms, progressive impairment of cognition has been extensively investigated. However, limited symptomatic relief in these patients by available medications demonstrates lack of understanding of the neuronal substrates, especially the PAE and/or AD-associated neuropsychiatric symptoms (NPSs). It is well accepted that apathy, the top ranked NPS in both PAE and AD, arises through interactions between genetic and environmental factors. PAE has been considered an environmental insult to the brain and AD high risk genes have been identified as top genetic factors facilitating the onset of NPSs. Together with the increased life expectancy by 8- 10 years in the USA in the last 50 years, the evaluation of interactions between PAE history and AD high-risk genes at the molecular, synaptic, circuit, and behavioral levels is highly urgent. Ca2+permeable(CP)-AMPARs in the nucleus accumbens (NAc) are hypothesized as the potential substrate in mediating the synaptic loss and the low motivation phenotype in subjects with high risk of AD and a history of PAE. In this proposal, three Specific Aims are designed to first evaluate, and then modify, synaptic CP-AMPARs (Aim1) and excitatory synaptic contacts (Aim 2) in the NAc, and motivation levels (Aim 3) in F344 wild type vs. transgenic AD rats at the adolescent, early adult and middle-aged stages. Our hope is to not only fill the gap in our understanding of neuronal mechanisms of apathy associated with AD and PAE, but also uncover novel neurobiological targets in the clinic to treat affected patients.