Research
Effect of ablated hippocampal neurogenesis on the formation and extinction of contextual fear memory
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* Corresponding author: Bong-Kiun Kaang kaang@snu.ac.kr
- † Equal contributors
1 National Creative Research Initiative Center for Memory, Department of Biological Sciences, College of Natural Sciences, Seoul National University, San 56-1 Silim-dong, Gwanak-gu, Seoul, 151-747, Korea
2 Laboratory of Radiation Effect, Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, 139-706, Korea
3 Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 139-706, Korea
4 Departments of Biochemistry and Molecular Biology, Hanyang University College of Medicine, 17 Haengdang-dong, Sungdong-gu, Seoul 133-791, Korea
Molecular Brain 2009, 2:1 doi:10.1186/1756-6606-2-1
Published: 13 January 2009Abstract
Newborn neurons in the subgranular zone (SGZ) of the hippocampus incorporate into the dentate gyrus and mature. Numerous studies have focused on hippocampal neurogenesis because of its importance in learning and memory. However, it is largely unknown whether hippocampal neurogenesis is involved in memory extinction per se. Here, we sought to examine the possibility that hippocampal neurogenesis may play a critical role in the formation and extinction of hippocampus-dependent contextual fear memory. By methylazoxymethanol acetate (MAM) or gamma-ray irradiation, hippocampal neurogenesis was impaired in adult mice. Under our experimental conditions, only a severe impairment of hippocampal neurogenesis inhibited the formation of contextual fear memory. However, the extinction of contextual fear memory was not affected. These results suggest that although adult newborn neurons contribute to contextual fear memory, they may not be involved in the extinction or erasure of hippocampus-dependent contextual fear memory.