Neuroplasticity and Behavioral Unit
Research Overview: Most neurons in the adult central nervous system are terminally differentiated and cannot be replaced when they die. However, research over the past decade has shown that small populations of new neurons are generated in the mature olfactory bulb and hippocampus. Interestingly, the production and survival of newborn cells can be regulated by a variety of environmental and neurochemical stimuli. In particular, voluntary exercise in a running wheel is correlated with increased hippocampal neurogenesis, enhanced synaptic plasticity and improved performance in a spatial maze in adult rodents. It is the aim of our research to understand this unexpected form of plasticity of the adult central nervous system and to begin to define underlying cellular and molecular mechanisms. It is our hope that this work may lead to methods of replacing or enhancing brain tissues lost or damaged due to neurodegeneration or injury.
Use of viral vectors to study hippocampal circuitry in vivo. Dentate gyrus granule cell neurons are labeled with lentivirus expressing green fluorescent protein. Direct inputs to these neurons are identified by using modified rabies virus expressing mCherry as a retrograde tracer.
Retroviral labeling of neural progenitor cells allows for investigation of the function of newborn neurons in the adult mammalian brain.
Exercise increases cell proliferation and neurogenesis in the adult mouse hippocampus and spatial learning in the Morris water maze.
Exercise improved spatial pattern separation in a task where the amount of newly born neurons correlated with performance. Here, a mouse chooses between two similar objects in close proximity to one another and has learned that only one of the objects is reinforced with a food reward. The photomicrograph shows double-labeling for NeuN (Red) and BrdU (Green) in the mouse dentate gyrus.