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Lv D, Xiao B, Liu H, Wang L, Li Y, Zhang YH, Jin Q. Enhanced NMDA receptor pathway and glutamate transmission in the hippocampal dentate gyrus mediate the spatial learning and memory impairment of obese rats. Pflugers Arch 2024; 476:821-831. [PMID: 38416255 PMCID: PMC11033237 DOI: 10.1007/s00424-024-02924-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/30/2024] [Accepted: 02/07/2024] [Indexed: 02/29/2024]
Abstract
Obesity has been linked with the impairment of spatial memory and synaptic plasticity but the molecular mechanisms remained unidentified. Since glutamatergic transmission and NMDA receptor neural pathways in hippocampal dentate gyrus (DG) are essential in the learning and memory, we aimed to investigate glutamate (Glu) and NMDA receptor signaling of DG in spatial learning and memory in diet-induced obesity (DIO) rats. Spatial learning and memory were assessed via Morris water maze (MWM) test on control (Ctr) and DIO rats. Extracellular concentration of Glu in the DG was determined using in vivo microdialysis and HPLC. The protein expressions of NMDA receptor subunit 2B (NR2B), brain-derived neurotrophic factor (BDNF), the activation of calcium/calmodulin-dependent kinase II (CaMKII) and cAMP-response-element-binding protein (CREB) in the DG were observed by western blot. Spatial learning and memory were impaired in DIO rats compared to those of Ctr. NR2B expression was increased, while BDNF expression and CaMKII and CREB activation were decreased in DG of DIO rats. Extracellular concentration of Glu was increased in Ctr on the 3rd and 4th days of the MWM test, but significant further increment was observed in DIO rats. Microinjection of an NMDA antagonist (MK-801) into the DG reversed spatial learning and memory impairment. Such effects were accompanied by greater BDNF expression and CaMKII/CREB activation in the DG of DIO rats. In conclusion, the enhancement of Glu-NMDA receptor transmission in the hippocampal DG contributes to the impairment of spatial learning and memory in DIO rats, maybe via the modulation of CaMKII-CREB-BDNF signaling pathway.
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Affiliation(s)
- Dingding Lv
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, 133002, China
| | - Bin Xiao
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, 133002, China
| | - Huaying Liu
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, 133002, China
| | - Linping Wang
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, 133002, China
| | - Yingshun Li
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, 133002, China
| | - Yin Hua Zhang
- Department of Physiology and Biomedical Sciences, Ischemia/Hypoxic Disease Institute, Seoul National University, College of Medicine, Seoul, Korea.
| | - Qinghua Jin
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, 133002, China.
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2
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Komleva YK, Lopatina OL, Gorina YV, Chernykh AI, Trufanova LV, Vais EF, Kharitonova EV, Zhukov EL, Vahtina LY, Medvedeva NN, Salmina AB. Expression of NLRP3 Inflammasomes in Neurogenic Niche Contributes to the Effect of Spatial Learning in Physiological Conditions but Not in Alzheimer's Type Neurodegeneration. Cell Mol Neurobiol 2021; 42:1355-1371. [PMID: 33392919 DOI: 10.1007/s10571-020-01021-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/27/2020] [Indexed: 12/27/2022]
Abstract
A common feature of neurodegenerative disorders, in particular Alzheimer's disease (AD), is a chronic neuroinflammation associated with aberrant neuroplasticity. Development of neuroinflammation affects efficacy of stem and progenitor cells proliferation, differentiation, migration, and integration of newborn cells into neural circuitry. However, precise mechanisms of neurogenesis alterations in neuroinflammation are not clear yet. It is well established that expression of NLRP3 inflammasomes in glial cells marks neuroinflammatory events, but less is known about contribution of NLRP3 to deregulation of neurogenesis within neurogenic niches and whether neural stem cells (NSCs), neural progenitor cells (NPCs) or immature neuroblasts may express inflammasomes in (patho)physiological conditions. Thus, we studied alterations of neurogenesis in rats with the AD model (intra-hippocampal injection of Aβ1-42). We found that in Aβ-affected brain, number of CD133+ cells was elevated after spatial training in the Morris water maze. The number of PSA-NCAM+ neuroblasts diminished by Aβ injection was completely restored by subsequent spatial learning. Spatial training leads to elevated expression of NLRP3 inflammasomes in the SGZ (subgranular zones): CD133+ and PSA-NCAM+ cells started to express NLRP3 in sham-operated, but not AD rats. Taken together, our data suggest that expression of NLRP3 inflammasomes in CD133+ and PSA-NCAM+ cells may contribute to stimulation of adult neurogenesis in physiological conditions, whereas Alzheimer's type neurodegeneration abolishes stimuli-induced overexpression of NLRP3 within the SGZ neurogenic niche.
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Affiliation(s)
- Yulia K Komleva
- The Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia. .,Research Institute of Molecular Medicine and Pathobiochemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia.
| | - O L Lopatina
- The Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - Ya V Gorina
- The Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - A I Chernykh
- Research Institute of Molecular Medicine and Pathobiochemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - L V Trufanova
- The Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - E F Vais
- The Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - E V Kharitonova
- The Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - E L Zhukov
- Department of Pathological Anatomy Named After Prof. P.G. Podzolkov, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - L Yu Vahtina
- Department of Human Anatomy, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - N N Medvedeva
- Department of Human Anatomy, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - A B Salmina
- The Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Ministry of Health of the Russian Federation, Professor V. F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
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3
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Sex Differences in Maturation and Attrition of Adult Neurogenesis in the Hippocampus. eNeuro 2020; 7:ENEURO.0468-19.2020. [PMID: 32586842 PMCID: PMC7369314 DOI: 10.1523/eneuro.0468-19.2020] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 12/13/2022] Open
Abstract
Sex differences exist in the regulation of adult neurogenesis in the hippocampus in response to hormones and cognitive training. Here, we investigated the trajectory and maturation rate of adult-born neurons in the dentate gyrus (DG) of male and female rats. Sprague Dawley rats were perfused 2 h, 24 h, one week (1w), 2w, or 3w after bromodeoxyuridine (BrdU) injection, a DNA synthesis marker that labels dividing progenitor cells and their progeny. Adult-born neurons (BrdU/NeuN-ir) matured faster in males compared with females. Males had a greater density of neural stem cells (Sox2-ir) in the dorsal, but not in the ventral, DG and had higher levels of cell proliferation (Ki67-ir) than non-proestrous females. However, males showed a greater reduction in neurogenesis between 1week and 2weeks after mitosis, whereas females showed similar levels of neurogenesis throughout the weeks. The faster maturation and greater attrition of new neurons in males compared with females suggests greater potential for neurogenesis to respond to external stimuli in males and emphasizes the importance of studying sex on adult hippocampal neurogenesis.
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Harris J, Mahone EM, Bjornsson HT. Molecularly confirmed Kabuki (Niikawa-Kuroki) syndrome patients demonstrate a specific cognitive profile with extensive visuospatial abnormalities. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2019; 63:489-497. [PMID: 30767315 PMCID: PMC6499655 DOI: 10.1111/jir.12596] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/13/2018] [Accepted: 01/07/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND Kabuki (Niikawa-Kuroki) syndrome (KS) is caused by disease-causing variants in either of two components (KMT2D and KDM6A) of the histone methylation machinery. Nearly all individuals with KS have cognitive difficulties, and most have intellectual disability. Recent studies on a mouse model of KS suggest disruption of normal adult neurogenesis in the granule cell layer of the dentate gyrus of the hippocampus. These mutant mice also demonstrate hippocampal memory defects compared with littermates, but this phenotype is rescued postnatally with agents that target the epigenetic machinery. If these findings are relevant to humans with KS, we would expect significant and disproportionate disruption of visuospatial functioning in these individuals. METHODS To test this hypothesis, we have compiled a battery to robustly explore visuospatial function. We prospectively recruited 22 patients with molecularly confirmed KS and 22 IQ-matched patients with intellectual disability. RESULTS We observed significant deficiencies in visual motor, visual perception and visual motor memory in the KS group compared with the IQ-matched group on several measures. In contrast, language function appeared to be marginally better in the KS group compared with the IQ-matched group in a sentence comprehension task. CONCLUSIONS Together, our data suggest specific disruption of visuospatial function, likely linked to the dentate gyrus, in individuals with KS and provide the groundwork for a novel and specific outcome measure for a clinical trial in a KS population.
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Affiliation(s)
- J Harris
- Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, USA
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - E M Mahone
- Department of Neuropsychology, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - H T Bjornsson
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
- Department of Genetics and Molecular Medicine, Landspitali University Hospital, Reykjavik, Iceland
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Galea LA, Roes MM, Dimech CJ, Chow C, Mahmoud R, Lieblich SE, Duarte-Guterman P. Premarin has opposing effects on spatial learning, neural activation, and serum cytokine levels in middle-aged female rats depending on reproductive history. Neurobiol Aging 2018; 70:291-307. [DOI: 10.1016/j.neurobiolaging.2018.06.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 06/23/2018] [Accepted: 06/24/2018] [Indexed: 01/28/2023]
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Baptista P, Andrade JP. Adult Hippocampal Neurogenesis: Regulation and Possible Functional and Clinical Correlates. Front Neuroanat 2018; 12:44. [PMID: 29922131 PMCID: PMC5996050 DOI: 10.3389/fnana.2018.00044] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 05/11/2018] [Indexed: 01/19/2023] Open
Abstract
The formation of new neurons in the adult central nervous system (CNS) has been recognized as one of the major findings in neuroanatomical research. The hippocampal formation (HF), one of the main targets of these investigations, holds a neurogenic niche widely recognized among several mammalian species and whose existence in the human brain has sparked controversy and extensive debate. Many cellular features from this region emphasize that hippocampal neurogenesis suffers changes with normal aging and, among regulatory factors, physical exercise and chronic stress provoke opposite effects on cell proliferation, maturation and survival. Considering the numerous functions attributable to the HF, increasing or decreasing the integration of new neurons in the delicate neuronal network might be significant for modulation of cognition and emotion. The role that immature and mature adult-born neurons play in this circuitry is still mostly unknown but it could prove fundamental to understand hippocampal-dependent cognitive processes, the pathophysiology of depression, and the therapeutic effects of antidepressant medication in modulating behavior and mental health.
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Affiliation(s)
- Pedro Baptista
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine of University of Porto, Porto, Portugal
| | - José P Andrade
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine of University of Porto, Porto, Portugal.,Center of Health Technology and Services Research (CINTESIS), Faculty of Medicine of University of Porto, Porto, Portugal
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A behavioral task with more opportunities for memory acquisition promotes the survival of new neurons in the adult dentate gyrus. Sci Rep 2018; 8:7369. [PMID: 29743494 PMCID: PMC5943398 DOI: 10.1038/s41598-018-25331-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/29/2018] [Indexed: 12/14/2022] Open
Abstract
It has been suggested that the dentate gyrus, particularly its new neurons generated via adult neurogenesis, is involved in memory acquisition and recall. Here, we trained rats in two types of Morris water maze tasks that are differentially associated with these two memory processes, and examined whether new neurons are differently affected by the two tasks performed during the second week of neuronal birth. Our results indicate that the task involving more opportunities to acquire new information better supports the survival of new neurons. Further, we assessed whether the two tasks differentially induce the expression of an immediate early gene, Zif268, which is known to be induced by neuronal activation. While the two tasks differentially induce Zif268 expression in the dentate gyrus, the proportions of new neurons activated were similar between the two tasks. Thus, we conclude that while the two tasks differentially activate the dentate gyrus, the task involving more opportunities for memory acquisition during the second week of the birth of new neurons better promotes the survival of the new neurons.
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8
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Lieberwirth C, Pan Y, Liu Y, Zhang Z, Wang Z. Hippocampal adult neurogenesis: Its regulation and potential role in spatial learning and memory. Brain Res 2016; 1644:127-40. [PMID: 27174001 PMCID: PMC5064285 DOI: 10.1016/j.brainres.2016.05.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 05/05/2016] [Accepted: 05/08/2016] [Indexed: 12/24/2022]
Abstract
Adult neurogenesis, defined here as progenitor cell division generating functionally integrated neurons in the adult brain, occurs within the hippocampus of numerous mammalian species including humans. The present review details various endogenous (e.g., neurotransmitters) and environmental (e.g., physical exercise) factors that have been shown to influence hippocampal adult neurogenesis. In addition, the potential involvement of adult-generated neurons in naturally-occurring spatial learning behavior is discussed by summarizing the literature focusing on traditional animal models (e.g., rats and mice), non-traditional animal models (e.g., tree shrews), as well as natural populations (e.g., chickadees and Siberian chipmunk).
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Affiliation(s)
| | - Yongliang Pan
- Program in Molecular and Translational Medicine, School of Medicine, Huzhou University, Huzhou 313000, PR China; State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing 100101, PR China.
| | - Yan Liu
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306-1270, USA
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing 100101, PR China
| | - Zuoxin Wang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306-1270, USA
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9
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Li G, Lv J, Wang J, Wan P, Li Y, Jiang H, Jin Q. GABA B receptors in the hippocampal dentate gyrus are involved in spatial learning and memory impairment in a rat model of vascular dementia. Brain Res Bull 2016; 124:190-7. [DOI: 10.1016/j.brainresbull.2016.05.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 04/20/2016] [Accepted: 05/11/2016] [Indexed: 11/24/2022]
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10
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Zeng J, Jiang X, Hu XF, Ma RH, Chai GS, Sun DS, Xu ZP, Li L, Bao J, Feng Q, Hu Y, Chu J, Chai DM, Hong XY, Wang JZ, Liu GP. Spatial training promotes short-term survival and neuron-like differentiation of newborn cells in Aβ1-42-injected rats. Neurobiol Aging 2016; 45:64-75. [PMID: 27459927 DOI: 10.1016/j.neurobiolaging.2016.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 05/05/2016] [Accepted: 05/07/2016] [Indexed: 01/22/2023]
Abstract
Neurogenesis plays a role in hippocampus-dependent learning and impaired neurogenesis may correlate with cognitive deficits in Alzheimer's disease. Spatial training influences the production and fate of newborn cells in hippocampus of normal animals, whereas the effects on neurogenesis in Alzheimer-like animal are not reported until now. Here, for the first time, we investigated the effect of Morris water maze training on proliferation, survival, apoptosis, migration, and differentiation of newborn cells in β-amyloid-treated Alzheimer-like rats. We found that spatial training could preserve a short-term survival of newborn cells generated before training, during the early phase, and the late phase of training. However, the training had no effect on the long-term survival of mature newborn cells generated at previously mentioned 3 different phases. We also demonstrated that spatial training promoted newborn cell differentiation preferentially to the neuron direction. These findings suggest a time-independent neurogenesis induced by spatial training, which may be indicative for the cognitive stimulation in Alzheimer's disease therapy.
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Affiliation(s)
- Juan Zeng
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China; Medicine Vocational and Technical School of Wuhan University, Wuhan, P. R. China
| | - Xia Jiang
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China; Department of Pathology, Hubei University of Chinese Medicine, Wuhan, P. R. China
| | - Xian-Feng Hu
- Wuhan Pu Ai Hospital, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Rong-Hong Ma
- Department of Laboratory Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Gao-Shang Chai
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China; Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, P. R. China
| | - Dong-Sheng Sun
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Zhi-Peng Xu
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Li Li
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Jian Bao
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Qiong Feng
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Yu Hu
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Jiang Chu
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Da-Min Chai
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Xiao-Yue Hong
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Jian-Zhi Wang
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, P. R. China
| | - Gong-Ping Liu
- Department of Pathophysiology, Key Laboratory of Neurological Diseases of Chinese Ministry of Education, the School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, P. R. China.
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11
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Gros A, Veyrac A, Laroche S. [Brain and memory: new neurons to remember]. Biol Aujourdhui 2016; 209:229-248. [PMID: 26820830 DOI: 10.1051/jbio/2015028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Indexed: 06/05/2023]
Abstract
A defining characteristic of the brain is its remarkable capacity to undergo activity-dependent functional and structural remodelling via mechanisms of plasticity that form the basis of our capacity to encode and retain memories. The prevailing model of how our brain stores new information about relationships between events or new abstract constructs suggests it resides in activity-driven modifications of synaptic strength and remodelling of neural networks brought about by cellular and molecular changes within the neurons activated during learning. To date, the idea that a form of activity-dependent synaptic plasticity known as long-term potentiation, or LTP, and the associated synaptic growth play a central role in the laying down of memories has received considerable support. Beyond this mechanism of plasticity at the synapse, adult neurogenesis, i.e. the birth and growth of new neurons, is another form of neural plasticity that occurs continuously in defined brain regions such as the dentate gyrus of the hippocampus. Here, based on work in the hippocampus, we review the processes and mechanisms of the generation and selection of new neurons in the adult brain and the accumulating evidence that supports the idea that this form of neural plasticity is essential to store and lead to retrievable hippocampal-dependent memories.
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Affiliation(s)
- Alexandra Gros
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Alexandra Veyrac
- Centre de Recherche en Neurosciences de Lyon, UMR 5292 CNRS, INSERM U1028, Université Lyon 1, 69366 Lyon, France
| | - Serge Laroche
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
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12
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Motta-Teixeira LC, Takada SH, Machado-Nils AV, Nogueira MI, Xavier GF. Spatial learning and neurogenesis: Effects of cessation of wheel running and survival of novel neurons by engagement in cognitive tasks. Hippocampus 2016; 26:794-803. [PMID: 26669934 DOI: 10.1002/hipo.22560] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2015] [Indexed: 01/01/2023]
Abstract
Physical exercise stimulates cell proliferation in the adult dentate gyrus and facilitates acquisition and/or retention of hippocampal-dependent tasks. It is established that regular physical exercise improves cognitive performance. However, it is unclear for how long these benefits last after its interruption. Independent groups of rats received both free access to either unlocked (EXE Treatment) or locked (No-EXE Treatment) running wheels for 7 days, and daily injections of bromodeoxyuridine (BrdU) in the last 3 days. After a time delay period of either 1, 3, or 6 weeks without training, the animals were tested in the Morris water maze (MWM) either in a working memory task dependent on hippocampal function (MWM-HD) or in a visible platform searching task, independent on hippocampal function (MWM-NH). Data confirmed that exposure of rats to 7 days of spontaneous wheel running increases cell proliferation and neurogenesis. In contrast, neurogenesis was not accompanied by significant improvements of performance in the working memory version of the MWM. Longer time delays between the end of exercise and the beginning of cognitive training in the MWM resulted in lower cell survival; that is, the number of novel surviving mature neurons was decreased when this delay was 6 weeks as compared with when it was 1 week. In addition, data showed that while exposure to the MWM-HD working memory task substantially increased survival of novel neurons, exposure to the MWM-NH task did not, thus indicating that survival of novel dentate gyrus neurons depends on the engagement of this brain region in performance of cognitive tasks. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Lívia Clemente Motta-Teixeira
- Department of Physiology, Institute of Biosciences, University of São Paulo, Rua Do Matão, Travessa 14, N. 101, São Paulo, 05508-090, SP, Brazil
| | - Silvia Honda Takada
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 2415, São Paulo, 05508-000, SP, Brazil
| | - Aline Vilar Machado-Nils
- Department of Physiology, Institute of Biosciences, University of São Paulo, Rua Do Matão, Travessa 14, N. 101, São Paulo, 05508-090, SP, Brazil
| | - Maria Inês Nogueira
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 2415, São Paulo, 05508-000, SP, Brazil
| | - Gilberto Fernando Xavier
- Department of Physiology, Institute of Biosciences, University of São Paulo, Rua Do Matão, Travessa 14, N. 101, São Paulo, 05508-090, SP, Brazil
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Jauregui-Huerta F, Zhang L, Yañez-Delgadillo G, Hernandez-Carrillo P, García-Estrada J, Luquín S. Hippocampal cytogenesis and spatial learning in senile rats exposed to chronic variable stress: effects of previous early life exposure to mild stress. Front Aging Neurosci 2015; 7:159. [PMID: 26347648 PMCID: PMC4539520 DOI: 10.3389/fnagi.2015.00159] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 07/31/2015] [Indexed: 12/01/2022] Open
Abstract
In this study, we exposed adult rats to chronic variable stress (CVS) and tested the hypothesis that previous early-life exposure to stress changes the manner in which older subjects respond to aversive conditions. To this end, we analyzed the cytogenic changes in the hippocampus and hippocampal-dependent spatial learning performance. The experiments were performed on 18-month-old male rats divided into four groups as follows: Control (old rats under standard laboratory conditions), Early-life stress (ELS; old rats who were exposed to environmental noise from postnatal days, PNDs 21–35), CVS + ELS (old rats exposed to a chronic stress protocol who were previously exposed to the early-life noise stress) and CVS (old rats who were exposed only to the chronic stress protocol). The Morris Water Maze (MWM) was employed to evaluate the spatial learning abilities of the rats at the end of the experiment. Immunohistochemistry against 5′Bromodeoxyuridine (BrdU) and glial fibrillar acidic protein (GFAP) was also conducted in the DG, CA1, CA2 and CA3 regions of the hippocampus. We confocally analyzed the cytogenic (BrdU-labeled cells) and astrogenic (BrdU + GFAP-labeled cells) changes produced by these conditions. Using this procedure, we found that stress diminished the total number of BrdU+ cells over the main proliferative area of the hippocampus (i.e., the dentate gyrus, DG) but increased the astrocyte phenotypes (GFAP + BrdU). The depleted BrdU+ cells were restored when the senile rats also experienced stress at the early stages of life. The MWM assessment demonstrated that stress also impairs the ability of the rats to learn the task. This impairment was not present when the stressful experience was preceded by the early-life exposure. Thus, our results support the idea that previous exposure to mild stressing agents may have beneficial effects on aged subjects.
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Affiliation(s)
- Fernando Jauregui-Huerta
- Departamento de Neurociencias, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara Guadalajara, Jalisco, Mexico
| | - Limei Zhang
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México México, Mexico
| | - Griselda Yañez-Delgadillo
- Departamento de Neurociencias, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara Guadalajara, Jalisco, Mexico
| | - Pamela Hernandez-Carrillo
- Departamento de Neurociencias, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara Guadalajara, Jalisco, Mexico
| | - Joaquín García-Estrada
- División de Neurociencias, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano del Seguro Social Guadalajara, Mexico
| | - Sonia Luquín
- Departamento de Neurociencias, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara Guadalajara, Jalisco, Mexico
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14
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Duarte-Guterman P, Yagi S, Chow C, Galea LAM. Hippocampal learning, memory, and neurogenesis: Effects of sex and estrogens across the lifespan in adults. Horm Behav 2015; 74:37-52. [PMID: 26122299 DOI: 10.1016/j.yhbeh.2015.05.024] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/29/2015] [Accepted: 05/26/2015] [Indexed: 01/12/2023]
Abstract
This article is part of a Special Issue "Estradiol and Cognition". There are sex differences in hippocampus-dependent cognition and neurogenesis suggesting that sex hormones are involved. Estrogens modulate certain forms of spatial and contextual memory and neurogenesis in the adult female rodent, and to a lesser extent male, hippocampus. This review focuses on the effects of sex and estrogens on hippocampal learning, memory, and neurogenesis in the young and aged adult rodent. We discuss how factors such as the type of estrogen, duration and dose of treatment, timing of treatment, and type of memory influence the effects of estrogens on cognition and neurogenesis. We also address how reproductive experience (pregnancy and mothering) and aging interact with estrogens to modulate hippocampal cognition and neurogenesis in females. Given the evidence that adult hippocampal neurogenesis plays a role in long-term spatial memory and pattern separation, we also discuss the functional implications of regulating neurogenesis in the hippocampus.
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Affiliation(s)
- Paula Duarte-Guterman
- Department of Psychology, Centre for Brain Health, Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Shunya Yagi
- Department of Psychology, Centre for Brain Health, Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Carmen Chow
- Department of Psychology, Centre for Brain Health, Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Liisa A M Galea
- Department of Psychology, Centre for Brain Health, Program in Neuroscience, University of British Columbia, Vancouver, Canada.
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15
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Storozheva ZI, Gruden MA, Proshin AT, Sewell RDE. Learning ability is a key outcome determinant of GSK-3 inhibition on visuospatial memory in rats. J Psychopharmacol 2015; 29:822-35. [PMID: 25735991 DOI: 10.1177/0269881115573805] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Learning aptitude has never been a focus of visuospatial performance studies, particularly on memory consolidation and reconsolidation. The aim of this study was to determine the consequences of learning ability on memory consolidation/reconsolidation following inhibition of glucose synthase kinase-3 (GSK-3) by 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8). The anxiety-like nature of rats was characterized in the elevated plus maze. The rats were then trained for four days in the Morris water maze (MWM) and classified as 'superior', 'intermediate' or 'inferior' learners. There were no major differences between superior, intermediate or inferior learners with respect to anxiety which might have influenced learning. After training (day-5), TDZD-8 (2.0 mg/kg) was administered and half of the cohort were exposed to a MWM retrieval trial. Ten days later, animals were subjected to repeated MWM learning. TDZD-8 without a retrieval trial impaired subsequent reconsolidation in inferior learners, but enhanced it in superior learners. There was no modification of performance in intermediate learners. In TDZD-8-treated subjects exposed to retrieval, the pattern of outcomes was identical whereby impairment of reconsolidation occurred in inferior learners, enhancement occurred in superior learners but there was no modification of performance in intermediate learners. Thus, learning ability was a key determinant of the qualitative outcome from GSK-3 inhibition on visuospatial memory.
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Affiliation(s)
- Zinaida I Storozheva
- Federal State Budgetary Scientific Institution, P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russian Federation Federal Medical Research Centre of Psychiatry and Narcology, Moscow, Russian Federation
| | - Marina A Gruden
- Federal State Budgetary Scientific Institution, P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russian Federation
| | - Andrey T Proshin
- Federal State Budgetary Scientific Institution, P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russian Federation
| | - Robert D E Sewell
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
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16
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Bjornsson HT, Benjamin JS, Zhang L, Weissman J, Gerber EE, Chen YC, Vaurio RG, Potter MC, Hansen KD, Dietz HC. Histone deacetylase inhibition rescues structural and functional brain deficits in a mouse model of Kabuki syndrome. Sci Transl Med 2015; 6:256ra135. [PMID: 25273096 DOI: 10.1126/scitranslmed.3009278] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Kabuki syndrome is caused by haploinsufficiency for either of two genes that promote the opening of chromatin. If an imbalance between open and closed chromatin is central to the pathogenesis of Kabuki syndrome, agents that promote chromatin opening might have therapeutic potential. We have characterized a mouse model of Kabuki syndrome with a heterozygous deletion in the gene encoding the lysine-specific methyltransferase 2D (Kmt2d), leading to impairment of methyltransferase function. In vitro reporter alleles demonstrated a reduction in histone 4 acetylation and histone 3 lysine 4 trimethylation (H3K4me3) activity in mouse embryonic fibroblasts from Kmt2d(+/βGeo) mice. These activities were normalized in response to AR-42, a histone deacetylase inhibitor. In vivo, deficiency of H3K4me3 in the dentate gyrus granule cell layer of Kmt2d(+/βGeo) mice correlated with reduced neurogenesis and hippocampal memory defects. These abnormalities improved upon postnatal treatment with AR-42. Our work suggests that a reversible deficiency in postnatal neurogenesis underlies intellectual disability in Kabuki syndrome.
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Affiliation(s)
- Hans T Bjornsson
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Joel S Benjamin
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Predoctoral Training Program in Human Genetics, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Li Zhang
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jacqueline Weissman
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Elizabeth E Gerber
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yi-Chun Chen
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Michelle C Potter
- Brain Science Institute, Neurology Department, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kasper D Hansen
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Biostatistics, Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Harry C Dietz
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Division of Pediatric Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Howard Hughes Medical Institute, Baltimore, MD 21205, USA
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17
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Prior high corticosterone exposure reduces activation of immature neurons in the ventral hippocampus in response to spatial and nonspatial memory. Hippocampus 2014; 25:329-44. [DOI: 10.1002/hipo.22375] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2014] [Indexed: 12/21/2022]
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18
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Darcy MJ, Trouche S, Jin SX, Feig LA. Ras-GRF2 mediates long-term potentiation, survival, and response to an enriched environment of newborn neurons in the hippocampus. Hippocampus 2014; 24:1317-29. [PMID: 24894950 DOI: 10.1002/hipo.22313] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2014] [Indexed: 01/04/2023]
Abstract
Hippocampal adult neurogenesis contributes to key functions of the dentate gyrus (DG), including contextual discrimination. This is due, at least in part, to the unique form of plasticity that new neurons display at a specific stage of their development when compared with the surrounding principal neurons. In addition, the contribution that newborn neurons make to dentate function can be enhanced by an increase in their numbers induced by a stimulating environment. However, signaling mechanisms that regulate these properties of newborn neurons are poorly understood. Here, we show that Ras-GRF2 (GRF2), a calcium-regulated exchange factor that can activate Ras and Rac GTPases, contributes to both of these properties of newborn neurons. Using Ras-GRF2 knockout mice and wild-type mice stereotactically injected with retrovirus containing shRNA against the exchange factor, we demonstrate that GRF2 promotes the survival of newborn neurons of the DG at approximately 1-2 weeks after their birth. GRF2 also controls the distinct form of long-term potentiation that is characteristic of new neurons of the hippocampus through its effector Erk MAP kinase. Moreover, the enhancement of neuron survival that occurs after mice are exposed to an enriched environment also involves GRF2 function. Consistent with these observations, GRF2 knockout mice display defective contextual discrimination. Overall, these findings indicate that GRF2 regulates both the basal level and environmentally induced increase of newborn neuron survival, as well as in the induction of a distinct form of synaptic plasticity of newborn neurons that contributes to distinct features of hippocampus-derived learning and memory.
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Affiliation(s)
- Michael J Darcy
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts
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19
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Galea LAM, Wainwright SR, Roes MM, Duarte-Guterman P, Chow C, Hamson DK. Sex, hormones and neurogenesis in the hippocampus: hormonal modulation of neurogenesis and potential functional implications. J Neuroendocrinol 2013; 25:1039-61. [PMID: 23822747 DOI: 10.1111/jne.12070] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 06/23/2013] [Accepted: 06/29/2013] [Indexed: 12/12/2022]
Abstract
The hippocampus is an area of the brain that undergoes dramatic plasticity in response to experience and hormone exposure. The hippocampus retains the ability to produce new neurones in most mammalian species and is a structure that is targeted in a number of neurodegenerative and neuropsychiatric diseases, many of which are influenced by both sex and sex hormone exposure. Intriguingly, gonadal and adrenal hormones affect the structure and function of the hippocampus differently in males and females. Adult neurogenesis in the hippocampus is regulated by both gonadal and adrenal hormones in a sex- and experience-dependent way. Sex differences in the effects of steroid hormones to modulate hippocampal plasticity should not be completely unexpected because the physiology of males and females is different, with the most notable difference being that females gestate and nurse the offspring. Furthermore, reproductive experience (i.e. pregnancy and mothering) results in permanent changes to the maternal brain, including the hippocampus. This review outlines the ability of gonadal and stress hormones to modulate multiple aspects of neurogenesis (cell proliferation and cell survival) in both male and female rodents. The function of adult neurogenesis in the hippocampus is linked to spatial memory and depression, and the present review provides early evidence of the functional links between the hormonal modulation of neurogenesis that may contribute to the regulation of cognition and stress.
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Affiliation(s)
- L A M Galea
- Department of Psychology, University of British Columbia, Vancouver, Canada
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20
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Chow C, Epp JR, Lieblich SE, Barha CK, Galea LAM. Sex differences in neurogenesis and activation of new neurons in response to spatial learning and memory. Psychoneuroendocrinology 2013; 38:1236-50. [PMID: 23219473 DOI: 10.1016/j.psyneuen.2012.11.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Revised: 10/30/2012] [Accepted: 11/07/2012] [Indexed: 11/29/2022]
Abstract
Adult hippocampal neurogenesis is often associated with hippocampus-dependent learning and memory. Throughout a new neuron's development, it is differentially sensitive to factors that can influence its survival and functionality. Previous research shows that spatial training that occurred 6-10 days after an injection of the DNA synthesis marker, bromodeoxyuridine (BrdU), increased cell survival in male rats. Because sex differences in spatial cognition and hippocampal neurogenesis have been reported, it is unclear whether spatial training would influence hippocampal neurogenesis in the same way in males and females. Therefore, this study examined sex differences in hippocampal neurogenesis following training in a spatial task. Male and female rats were trained in the spatial or cued version of the Morris water maze 6-10 days after one injection of BrdU (200mg/kg). Twenty days following BrdU injection, all animals were given a probe trial and perfused. Males performed better in the spatial, but not cue, task than females. Spatial training increased BrdU-labeled cells relative to cue training only in males, but both males and females showed greater activation of new cells (BrdU co-labeled with immediate early gene product zif268) after spatial training compared to cue training. Furthermore, performance during spatial training was positively correlated with cell activation in females but not males. This study shows that while spatial training differentially regulates hippocampal neurogenesis in males and females, the activity of new neurons in response to spatial memory retrieval is similar. These findings highlight the importance of sex on neural plasticity and cognition.
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Affiliation(s)
- Carmen Chow
- Program in Neuroscience, Department of Psychology, Brain Research Centre, University of British Columbia, Vancouver, BC, Canada
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21
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Fournier NM, Botterill JJ, Marks WN, Guskjolen AJ, Kalynchuk LE. Impaired recruitment of seizure-generated neurons into functional memory networks of the adult dentate gyrus following long-term amygdala kindling. Exp Neurol 2013; 244:96-104. [DOI: 10.1016/j.expneurol.2012.11.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 11/17/2012] [Accepted: 11/21/2012] [Indexed: 02/04/2023]
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22
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Epp JR, Chow C, Galea LAM. Hippocampus-dependent learning influences hippocampal neurogenesis. Front Neurosci 2013; 7:57. [PMID: 23596385 PMCID: PMC3627134 DOI: 10.3389/fnins.2013.00057] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 03/28/2013] [Indexed: 12/26/2022] Open
Abstract
The structure of the mammalian hippocampus continues to be modified throughout life by continuous addition of neurons in the dentate gyrus. Although the existence of adult neurogenesis is now widely accepted the function that adult generated granule cells play is a topic of intense debate. Many studies have argued that adult generated neurons, due to unique physiological characteristics, play a unique role in hippocampus-dependent learning and memory. However, it is not currently clear whether this is the case or what specific capability adult generated neurons may confer that developmentally generated neurons do not. These questions have been addressed in numerous ways, from examining the effects of increasing or decreasing neurogenesis to computational modeling. One particular area of research has examined the effects of hippocampus dependent learning on proliferation, survival, integration and activation of immature neurons in response to memory retrieval. Within this subfield there remains a range of data showing that hippocampus dependent learning may increase, decrease or alternatively may not alter these components of neurogenesis in the hippocampus. Determining how and when hippocampus-dependent learning alters adult neurogenesis will help to further clarify the role of adult generated neurons. There are many variables (such as age of immature neurons, species, strain, sex, stress, task difficulty, and type of learning) as well as numerous methodological differences (such as marker type, quantification techniques, apparatus size etc.) that could all be crucial for a clear understanding of the interaction between learning and neurogenesis. Here, we review these findings and discuss the different conditions under which hippocampus-dependent learning impacts adult neurogenesis in the dentate gyrus.
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Affiliation(s)
- Jonathan R. Epp
- *Correspondence: Jonathan R. Epp, Neurosciences and Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada. e-mail: ;
| | | | - Liisa A. M. Galea
- Department of Psychology, Program in Neuroscience, Brain Research Centre, University of British ColumbiaVancouver, BC, Canada
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23
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Luu P, Sill OC, Gao L, Becker S, Wojtowicz JM, Smith DM. The role of adult hippocampal neurogenesis in reducing interference. Behav Neurosci 2013; 126:381-91. [PMID: 22642883 DOI: 10.1037/a0028252] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Adult neurogenesis in the hippocampal dentate gyrus plays an important role in learning and memory. However, the precise contribution of the new neurons to hippocampal function remains controversial. Emerging evidence suggests that neurogenesis is important for pattern separation and for mitigating interference when similar items must be learned at different times. In the present study, we directly test this prediction using a recently developed olfactory memory task that has those specific features. In this task, rats learn two highly interfering lists of odor pairs, one after the other, in either the same or in different contexts. Consistent with our hypothesis, focal cranial irradiation, resulting in selective reduction of neurogenesis within the dentate gyrus, significantly impaired the ability to overcome interference during learning of the second list. The ability to learn a single odor list was unimpaired. We also show that irradiation had no effect on learning in a hippocampal-dependent spatial alternation task. Although both tasks involved learning interfering responses, the time course for learning the interfering items differed. Learning the interfering odor lists took place sequentially, over the course of several sessions, whereas learning the interfering spatial locations took place concurrently, within each session. Thus, the gradual addition of new neurons may have provided a pattern separation mechanism for the olfactory task but not for the maze task. These findings demonstrate a role for neurogenesis in resolving interference and they are consistent with models suggesting a critical role for neurogenesis in pattern separation.
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Affiliation(s)
- Paul Luu
- Department of Physiology, University of Toronto
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24
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Kumazawa-Manita N, Hama H, Miyawaki A, Iriki A. Tool use specific adult neurogenesis and synaptogenesis in rodent (Octodon degus) hippocampus. PLoS One 2013; 8:e58649. [PMID: 23516527 PMCID: PMC3596278 DOI: 10.1371/journal.pone.0058649] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 02/07/2013] [Indexed: 01/24/2023] Open
Abstract
We previously demonstrated that degus (Octodon degus), which are a species of small caviomorph rodents, could be trained to use a T-shaped rake as a hand tool to expand accessible spaces. To elucidate the neurobiological underpinnings of this higher brain function, we compared this tool use learning task with a simple spatial (radial maze) memory task and investigated the changes that were induced in the hippocampal neural circuits known to subserve spatial perception and learning. With the exposure to an enriched environment in home cage, adult neurogenesis in the dentate gyrus of the hippocampus was augmented by tool use learning, but not radial maze learning, when compared to control conditions. Furthermore, the proportion of new synapses formed in the CA3 region of the hippocampus, the target area for projections of mossy fiber axons emanating from newborn neurons, was specifically increased by tool use learning. Thus, active tool use behavior by rodents, learned through multiple training sessions, requires the hippocampus to generate more novel neurons and synapses than spatial information processing in radial maze learning.
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Affiliation(s)
- Noriko Kumazawa-Manita
- Laboratory for Symbolic Cognitive Development, RIKEN Brain Science Institute, Wako, Japan
| | - Hiroshi Hama
- Laboratory for Cell Function Dynamics, RIKEN Brain Science Institute, Wako, Japan
| | - Atsushi Miyawaki
- Laboratory for Cell Function Dynamics, RIKEN Brain Science Institute, Wako, Japan
| | - Atsushi Iriki
- Laboratory for Symbolic Cognitive Development, RIKEN Brain Science Institute, Wako, Japan
- * E-mail:
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25
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McClure RES, Barha CK, Galea LAM. 17β-Estradiol, but not estrone, increases the survival and activation of new neurons in the hippocampus in response to spatial memory in adult female rats. Horm Behav 2013; 63:144-57. [PMID: 23063473 DOI: 10.1016/j.yhbeh.2012.09.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 09/18/2012] [Accepted: 09/22/2012] [Indexed: 10/27/2022]
Abstract
Estrogens fluctuate across the lifespan in women, with circulating 17β-estradiol levels higher pre-menopause than estrone and circulating estrone levels higher postmenopause than 17β-estradiol. Estrone is a common component of hormone replacement therapies, but research shows that 17β-estradiol may have a greater positive impact on cognition. Previous studies show that acute estrone and 17β-estradiol impact hippocampus-dependent learning and cell proliferation in the dentate gyrus in a dose-dependent manner in adult female rats. The current study explores how chronic treatment with estrone and 17β-estradiol differentially influences spatial learning, hippocampal neurogenesis and activation of new neurons in response to spatial memory. Adult female rats received daily injections of vehicle (sesame oil), or a 10 μg dose of either 17β-estradiol or estrone for 20 days. One day following the first hormone injection all rats were injected with the DNA synthesis marker, bromodeoxyuridine. On days 11-15 after BrdU injection rats were trained on a spatial reference version of the Morris water maze, and five days later (day 20 of estrogens treatment) were given a probe trial to assess memory retention. Cell proliferation was assessed by the endogenous cell cycle marker, Ki67, cell survival was assessed by counting the number and density of BrdU-ir cells in the dentate gyrus and cell activation was assessed by the percentage of BrdU-ir cells that were co-labelled with the immediate early gene product zif268. There were no significant differences between groups in acquisition or retention of Morris water maze. However, the 17β-estradiol group had significantly higher, while the estrone group had significantly lower, levels of cell survival (BrdU-ir cells) in the dentate gyrus compared to controls. Furthermore, rats injected with 17β-estradiol showed significantly higher levels of activation of new neurons in response to spatial memory compared to controls. These results provide insight into how estrogens differentially influence the brain and behavior, and may provide insight into the development of hormone replacement therapies for women.
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Affiliation(s)
- Robyn E S McClure
- Department of Psychology, Graduate Program in Neuroscience, Brain Research Centre, University of British Columbia, Vancouver, BC, Canada
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26
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Barha CK, Galea LAM. The hormone therapy, Premarin, impairs hippocampus-dependent spatial learning and memory and reduces activation of new granule neurons in response to memory in female rats. Neurobiol Aging 2012; 34:986-1004. [PMID: 22938820 DOI: 10.1016/j.neurobiolaging.2012.07.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/29/2012] [Accepted: 07/11/2012] [Indexed: 12/25/2022]
Abstract
Estrogens have been implicated as possible therapeutic agents for improving cognition in postmenopausal women and have been linked to neurodegenerative disorders such as Alzheimer's disease. However, the utility of Premarin (Wyeth Pharmaceuticals, Markham, ON, Canada), a conjugated equine estrogen and the most commonly prescribed hormone therapy, has recently been questioned. The purpose of this study was to investigate the effects of Premarin at 2 different doses (10 or 20 μg) on hippocampus-dependent spatial learning and memory, hippocampal neurogenesis, and new neuronal activation using a rodent model of surgical menopause. Rats were treated daily with subcutaneous injections of Premarin and trained on the spatial working/reference memory version of the radial arm maze. Premarin impaired spatial reference and working learning and memory, increased hippocampal neurogenesis, but either decreased or increased activation of new neurons in response to memory retrieval as indexed by the expression of the immediate early gene product zif268, depending on the maturity of cells examined. This activation of new neurons was related to impaired performance in Premarin-treated but not control-treated female rats. These results indicate that Premarin may be impairing hippocampus-dependent learning and memory by negatively altering the neurogenic environment in the dentate gyrus thus disrupting normal activity of new neurons.
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Affiliation(s)
- Cindy K Barha
- Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada
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27
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McCormick CM, Thomas CM, Sheridan CS, Nixon F, Flynn JA, Mathews IZ. Social instability stress in adolescent male rats alters hippocampal neurogenesis and produces deficits in spatial location memory in adulthood. Hippocampus 2011; 22:1300-12. [PMID: 21805526 DOI: 10.1002/hipo.20966] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2011] [Indexed: 02/05/2023]
Abstract
The ongoing development of the hippocampus in adolescence may be vulnerable to stressors. The effects of social instability stress (SS) in adolescence (daily 1 h isolation and change of cage partner postnatal days 30-45) on cell proliferation in the dentate gyrus (DG) in adolescence (on days 33 and 46, experiment 1) and in adulthood (experiment 2) was examined in Long Evans male rats and compared to nonstressed controls (CTL). Additionally, in experiment 2, a separate group of SS and CTL rats was tested on either a spatial (hippocampal-dependent) or nonspatial (nonhippocampal dependent) version of an object memory test and also were used to investigate hippocampal expression of markers of synaptic plasticity. No memory impairment was evident until the SS rats were adults, and the impairment was only on the spatial test. SS rats initially (postnatal day 33) had increased cell proliferation based on counts of Ki67 immunoreactive (ir) cells and greater survival of immature neurons based on counts of doublecortin ir cells on day 46 and in adulthood, irrespective of behavioral testing. Counts of microglia in the DG did not differ by stress group, but behavioral testing was associated with reduced microglia counts compared to nontested rats. As adults, SS and CTL rats did not differ in hippocampal expression of synaptophysin, but compared to CTL rats, SS rats had higher expression of basal calcium/calmodulin-dependent kinase II (CamKII), and lower expression of the phosphorylated CamKII subunit threonine 286, signaling molecules related to synaptic plasticity. The results are contrasted with those from previous reports of chronic stress in adult rats, and we conclude that adolescent stress alters the ongoing development of the hippocampus leading to impaired spatial memory in adulthood, highlighting the heightened vulnerability to stressors in adolescence.
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Affiliation(s)
- Cheryl M McCormick
- Department of Psychology, Brock University, St Catharines, Ontario, Canada.
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Snyder JS, Cameron HA. Could adult hippocampal neurogenesis be relevant for human behavior? Behav Brain Res 2011; 227:384-90. [PMID: 21736900 DOI: 10.1016/j.bbr.2011.06.024] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 06/02/2011] [Accepted: 06/20/2011] [Indexed: 12/21/2022]
Abstract
Although the function of adult neurogenesis is still unclear, tools for directly studying the behavioral role of new hippocampal neurons now exist in rodents. Since similar studies are impossible to do in humans, it is important to assess whether the role of new neurons in rodents is likely to be similar to that in humans. One feature of adult neurogenesis that varies tremendously across species is the number of neurons that are generated, so a key question is whether there are enough neurons generated in humans to impact function. In this review we examine neuroanatomy and circuit function in the hippocampus to ask how many granule neurons are needed to impact hippocampal function and then discuss what is known about numbers of new neurons produced in adult rats and humans. We conclude that relatively small numbers of neurons could affect hippocampal circuits and that the magnitude of adult neurogenesis in adult rats and humans is probably larger than generally believed.
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Affiliation(s)
- Jason S Snyder
- Unit on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Building 35/3C911, MSC3718, Bethesda, MD 20892, USA.
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Complementary activation of hippocampal-cortical subregions and immature neurons following chronic training in single and multiple context versions of the water maze. Behav Brain Res 2011; 227:330-9. [PMID: 21736899 DOI: 10.1016/j.bbr.2011.06.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Revised: 05/31/2011] [Accepted: 06/20/2011] [Indexed: 11/22/2022]
Abstract
Neurobiological studies of memory typically involve single learning sessions that last minutes or days. In natural settings, however, animals are constantly learning. Here we investigated how several weeks of spatial water maze training influences subsequent activation of neocortical and hippocampal subregions, including adult-born neurons. Mice were either trained in a single context or in a variant of the task in which the spatial cues and platform location changed every 3 days, requiring constant new learning. On the final day, half of the mice in each training group were tested in a novel context and the other half were tested in their previous, familiar context. Two hours later mice were perfused to measure subregion-specific expression of the immediate-early gene zif268, a marker of neuronal activation. None of the training paradigms affected the magnitude of adult neurogenesis. However, different neuronal populations were activated depending on prior training history, final context novelty, or a combination of these 2 factors. The anterior cingulate cortex was more activated by novel context exposure, regardless of the type of prior training. The suprapyramidal blade of the dentate gyrus and region CA3 showed greater activation in mice trained in multiple contexts, primarily after exposure to a familiar context. In immature granule neurons, multiple context training enhanced activation regardless of final context novelty. CA1 showed no significant changes in zif268 expression across any training condition. In naïve control mice, training on the final day increased zif268 expression in CA3, CA1 and the anterior cingulate cortex, but not the dentate gyrus, relative to mice that remained in their cages (transport controls). Unexpectedly, immature granule cells showed a decrease in zif268 expression in naïve learners relative to transport controls. These findings suggest novel and complementary roles for hippocampal, neocortical, and immature neuronal populations in learning and memory.
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