Functional significance of adult hippocampal neurogenesis

The hippocampus is critically important for learning and memory and is one of only two brain regions than can produce new neurons in adulthood. There is some evidence that the addition of new neurons (neurogenesis) in the hippocampus is involved in or may even be required for the normal functions of this region. The rate of neurogenesis declines with age. It is widely accepted that aging is also associated with a decrease in memory performance, especially on the types of tasks that require the hippocampus. Decreased neurogenesis has been proposed as one possible factor that may reduce the efficiency of hippocampus-mediated learning and memory. And while there is believed to be a relationship between hippocampus-dependent learning and cell proliferation and survival, it’s not known What exactly this relationship is: whether neuronal growth affects hippocampus-dependent learning, or whether hippocampus-dependent learning affects the rate of neurogenesis. Other studies also suggest there may be a critical cellular age for new neurons when their survival can be altered. However, given the many conflicting studies in the literature, it is unlikely that there is a simple relationship between level of neurogenesis and memory performance. Jonathan Epp is exploring these various factors to determine the processes by which hippocampal neurogenesis occurs in adulthood, and the importance of neurogenesis to learning and memory. Using animal models, he will clarify whether cell survival can be enhanced at all times or whether there is a critical cellular age during which survival altering factors may have an impact. Epp hopes that by developing a better understanding of these relationships in the brain, this knowledge could be applied to generating therapeutic strategies for dealing with memory loss associated with aging, dementia and brain injury