Join us for the Wickens Lecture with Dr. Heather Cameron (Chief, Section on Neuroplasticity, National Institute of Mental Health)!
Title: What is the function of adult hippocampal neurogenesis?
Abstract: Abstract: Dentate gyrus granule cells are generated throughout life and integrate into hippocampal circuits, but their effects on cognition and behavior are unclear. We use pharmacogenetic techniques to inhibit production of new neurons in adult mice and rats to model the structural and behavioral impacts of chronic neurogenesis suppression that might be seen with stress, depression, or aging. Well-established roles for the hippocampus in learning and memory suggest that preventing adult neurogenesis should affect some aspects of these cognitive processes. However, we find that learning and memory are largely intact in animals lacking adult neurogenesis. Instead, we see effects on shifting of attention, motivation to work for unpredictable rewards, and decisions involving conflicts between competing goals or stimuli.Rats and mice with neurogenesis suppression show robust differences from control animals in an approach-approach gambling task, an approach-avoidance platform-mediated avoidance task, and tests of social aggression – all situations with inherently conflicting behavioral options. We also find that adult neurogenesis is required for growth of ventral CA1 volume and increased novelty approach behavior following rewarded learning or during recovery from stress. Taken together, our work suggests that adult neurogenesis may direct attention toward lower salience stimuli and alternate strategies, driving focus toward the most important goals in threatening environments and increasing curiosity and exploration in safer environments.