Journal Article

Optical controlling reveals time-dependent roles for adult-born dentate granule cells

Janoschka, Stephen R, Ge, Shaoyu, Gu, Yan, Arruda-Carvalho, Maithe, Wang, Jia, Frankland, Paul W, Josselyn, Sheena A

2012

Overview

Newly generated dentate granule cells in the hippocampus at 4 weeks after their 'birth' are more plastic than existing neurons. The authors use a combined retroviral and optogenetic approach to show that silencing these 4-week-old cells, but not cells of other ages, impaired retrieval of hippocampal memory. Accumulating evidence suggests that global depletion of adult hippocampal neurogenesis influences its function and that the timing of the depletion affects the deficits. However, the behavioral roles of adult-born neurons during their establishment of projections to CA3 pyramidal neurons remain largely unknown. We used a combination of retroviral and optogenetic approaches to birth date and reversibly control a group of adult-born neurons in adult mice. Adult-born neurons formed functional synapses on CA3 pyramidal neurons as early as 2 weeks after birth, and this projection to the CA3 area became stable by 4 weeks in age. Newborn neurons at this age were more plastic than neurons at other stages. Notably, we found that reversibly silencing this cohort of ∼4-week-old cells after training, but not cells of other ages, substantially disrupted retrieval of hippocampal memory. Our results identify a restricted time window for adult-born neurons essential in hippocampal memory retrieval.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: 631/378/1595/1554 / 631/378/2591 / 631/378/368 / Age Factors / Animal Genetics and Genomics / Animals / Behavioral Sciences / Biological Techniques / Biomedicine / Conditioning, Operant - physiology / Dentate gyrus / Dentate Gyrus - cytology / Dentate Gyrus - growth & development / Female / Maze Learning - physiology / Memory / Mice / Mice, Inbred C57BL / Neurobiology / Neurogenesis / Neurogenesis - physiology / Neuronal Plasticity - physiology / Neurons / Neurosciences / Parahippocampal region / Physiological aspects / Properties / Pyramidal Cells - growth & development / Random Allocation / Time Factors