Approximately 50 years ago, newly generated neurons were discovered in the adult hippocampus of the rat brain. This discovery contradicted a key principle in mammalian developmental neurobiology—that all the neurons of the brain are made during early development—and led to intensive study to find out how new neurons are generated and how the process of neurogenesis is regulated. Since then, a unique population of adult neural stem cells has been identified, and many of the molecular pathways that control their self-renewal, proliferation, and cell fate have been elucidated. However, the presence of new neurons in the adult brain also poses intriguing functional questions that have, as yet, gone largely unanswered. Why is adult neurogenesis restricted to select brain regions? What functional benefit do these new cells confer? Indeed, the field of adult neurogenesis offers a unique opportunity to study naïve neurons as they mature, form connections with existing neural networks, and begin to participate in information processing. We review the basics of adult NSC biology and the maturation of newborn neurons. In particular, we focus on new neurons in the hippocampus, and how they contribute to function in this key memory-forming structure of the brain.
Table of Contents: Acknowledgments / Introduction / A Day in the Life of a Hippocampal Neural Stem Cell / Dynamic Regulation of Neurogenesis and Maturation / The Function of New Neurons / Neurogenesis as a Regulator of Affective State / Conclusions / References / Author Biographies
Aaron Friedman is a graduate student in the Ph.D. program of the Department of Integrative Biology at UC Berkeley. His research, supported by a graduate fellowship from the National Science Foundation, investigates how newborn neurons respond to emotional input, and their potential roles in regulating emotional memory. Outside of lab, Aaron enjoys cooking the fresh produce available in the San Francisco Bay Area and backpacking in the High Sierras. Daniela Kaufer is an Associate Professor in the Department of Integrative Biology and the Helen Wills Neuroscience Institute at UC Berkeley. She was born and raised in Israel where she studied Biological Sciences in the Technion, and received her Ph.D. in Molecular Biochemistry at the Hebrew University. She was a Human Frontiers Postdoctoral Fellow at Stanford University, before joining the UC Berkeley faculty in 2005. Daniela's lab studies brain plasticity throughout life in the face of stress and neurological insults, with a particular focus on plasticity involving adult neural stem cells and across the neurovascular unit; neurons, astrocytes, oligodendrocytes and the components of the blood brain barrier. Kaufer has published in numerous journals including Nature Neuroscience, Nature, eLIFE, the Proceedings of the National Academy of Sciences, The Journal of Neuroscience, Molecular Psychiatry, Nature Medicine, and Science. Professor Kaufer is the recipient of the 2010 National Institute of Mental Health Directorâs New Innovator Award (BRAINS), as well as the NARSAD Young Investigator Award and a BAKAR fellowship. She is an elected associate member of the Canadian Institute for Advanced Research (CIFAR). Research in the Kaufer lab is currently funded by the NIH, the CURE foundation, and the Siebel Stem Cell Foundation.