Research Projects

Memory formation is a complex process involving acquisition, consolidation, and retrieval. Adult hippocampal neurogenesis (AHN) plays a crucial role in hippocampal-dependent memory consolidation, with increased neurogenesis enhancing learning and ablation causing memory impairment. The role of conditioned memory, such as trace-appetitive-conditioned memory, delay-appetitive-conditioned memory, and fear-conditioned memory, on AHN and its underlying mechanism is not well understood. Sleep plays a crucial role in the consolidation of conditioned memory and adult neurogenesis in the hippocampus. Short-term sleep deprivation soon after conditioning impairs the consolidation of conditioned memory, while prolonged sleep-deprivation 24 hours or more significantly alters the proliferation rate of neurogenesis in the hippocampus. It is unclear if prolonged sleep deprivation total sleep and/or REM sleep deprivation soon after conditioning appetitive conditioning and fear conditioning alters learning-induced neurogenesis in the hippocampus. Adult hippocampal neurogenesis is highly plastic and significantly modulated by hippocampal neuronal activity. Post-learning increase in newly proliferating neurons in the hippocampus and post-learning sleep play important roles in memory consolidation. Chronic sleep-deprivation immediately after learning a new task alters adult neurogenesis. Neuronal activity increases during memory acquisition and is reactivated during post-learning sleep. However, it is not known if hippocampal glutamatergic neurons involved in long-term potentiation of associative memories are reactivated during post-learning sleep.