Tsunoda, Susan Project Summary Age is perhaps the most significant contributing factor to multiple neurological diseases, including Alzheimer’s Disease (AD). Our overarching hypothesis is that protein targets affected during normal aging may be especially affected in age-related disease conditions. In this proposal, we focus on the voltage-dependent K+ channel, Kv4, as such a target. Multiple studies have found that Aβ42 induces a decline in Kv4 channels that contributes to downstream cognitive and motor pathologies. Here, we will examine whether there is a decline in Kv4 channels with normal aging, whether reactive oxygen species (ROS) that arise with both normal aging and Aβ42 accumulation lead to this progressive loss of Kv4, and whether loss of Kv4 leads to signs of early aging and a shortened lifespan. Drosophila offers an ideal model for combining its powerful molecular-genetic toolkit with a short lifespan to study how aging/Aβ42 accumulation affects neuronal signaling. We propose: 1) to test the hypothesis that Kv4 channels are progressively lost with age by examining Kv4 mRNA, protein level and localization, as well as current, 2) to test the hypothesis that the age/Aβ42-dependent accumulation of ROS affects Kv4 channels, and 3) to test if normal age-related decline in motor activity and lifespan are improved when levels of Kv4 are genetically restored, and exacerbated when Kv4 is absent.