Neuroplasticity and Behavioral Unit
Henriette van Praag received her Ph.D. from the Department of Psychobiology at Tel-Aviv University in 1992 for her work studying the development of opiate receptor function with Dr. Hanan Frenk. She did her postdoctoral research on the role of nerve growth factors in brain injury at Robert Wood Johnson Medical School in New Jersey with Dr. Ira Black from 1992-1997. She continued her research in brain regeneration as a staff scientist with Dr. Fred Gage in the Laboratory of Genetics at the Salk Institute for Biological Studies in La Jolla, California from 1997-2007. Specifically, she researched the regulation of the birth of new neurons in the adult hippocampus, a brain area that is important in learning and memory, and made significant discoveries pertaining to the regulation of neurogenesis by exercise and the functional integration of new neurons into the hippocampus.
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.