Long-term exposure to a hypomagnetic field attenuates adult hippocampal neurogenesis and cognition

AbstractAdult hippocampal neurogenesis contributes to learning and memory, and is sensitive to a variety of environmental stimuli. Exposure to a hypomagnetic field (HMF) influences the cognitive processes of various animals, from insects to human beings. However, whether HMF exposure affect adult hippocampal neurogenesis and hippocampus-dependent cognitions is still an enigma. Here, we showed that male C57BL/6 J mice exposed to HMF by means of near elimination of the geomagnetic field (GMF) exhibit significant impairments of adult hippocampal neurogenesis and hippocampus-dependent learning, which is strongly correlated with a reduction in the content of reactive oxygen species (ROS). However, these deficits seen in HMF-exposed mice could be rescued either by elevating ROS levels through pharmacological inhibition of ROS removal or by returning them back to GMF. Therefore, our results suggest that GMF plays an important role in adult hippocampal neurogenesis through maintaining appropriate endogenous ROS levels.

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Elimination of the geomagnetic field impairs adult hippocampal neurogenesis and cognition

10.5194/egusphere-egu2020-18667 ◽

2020 ◽

Author(s):

Bingfang Zhang ◽

Lei Wang ◽

Aisheng Zhan ◽

Lanxiang Tian ◽

Min Wang ◽

...

Keyword(s):

Developmental Biology ◽

Geomagnetic Field ◽

Hippocampal Neurogenesis ◽

Adult Hippocampal Neurogenesis ◽

Human Beings ◽

Deep Space ◽

Chinese Academy Of Sciences ◽

Adult Hippocampus ◽

Academy Of Sciences

Elimination of the geomagnetic field impairs adult hippocampal neurogenesis and cognitionBingfang Zhang1,2,4, Lei Wang3,4, Aisheng Zhan1,2,4, Min Wang3, Lanxiang Tian1,2,*, Weixiang Guo3,4,*, Yongxin Pan1,2,4,1Biogeomagnetism group, Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China2Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing 100029, China3State Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China4University of Chinese Academy of Sciences, Beijing 100049, ChinaThe geomagnetic field (present-day intensity 25-65 &#956;T, GMF) plays a fundamental role in the survival and evolution of organisms, but organisms including human beings could be exposed to hypomagnetic field (HMF, intensity < 5 &#956;T), e.g., during geomagnetic polarity reversals, some artificial environments without GMF such as magnetic shielded room, and the prolonged periods in deep-space travelling. Previous studies have shown that HMF exposure could trigger central nervous system (CNS) dysfunction-like behavioral effects and influence the cognitive processes of various animals, from insects to human beings. However, the underlying mechanism is still an enigma. In general, adult hippocampus continuously generates new-born neurons throughout animals&#8217; life which are functionally integrated into hippocampal circuits and contribute to memory and learning, and the process of adult neurogenesis has been shown to be strongly influenced by a variety of environment stimuli. Here, we show that long-term HMF exposure markedly attenuates cell proliferation, influences multiple stages of neurogenesis of adult hippocampus, resulting in the impairments of hippocampal neurogenesis and hippocampus-dependent cognition of mice. This study provides new insights into the potential risk of long-term HMF exposure on adult hippocampus in deep space missions.

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Radical pairs may explain reactive oxygen species-mediated effects of hypomagnetic field on neurogenesis

10.1101/2021.10.24.465632 ◽

2021 ◽

Author(s):

Rishabh Rishabh ◽

Hadi Zadeh-Haghighi ◽

Dennis Salahub ◽

Christoph Simon

Keyword(s):

Reactive Oxygen Species ◽

Radical Pair ◽

Experimental Studies ◽

Reactive Oxygen ◽

Hippocampal Neurogenesis ◽

Adult Hippocampal Neurogenesis ◽

Radical Pair Mechanism ◽

Oxygen Species ◽

Field Effects ◽

Hypomagnetic Field

Exposures to a hypomagnetic field can affect biological processes. Recently, it has been observed that hypomagnetic field exposure can adversely affect adult hippocampal neurogenesis and hippocampus-dependent cognition in mice. In the same study, the role of reactive oxygen species (ROS) in hypomagnetic field effects has been demonstrated. However, the mechanistic reasons behind this effect are not clear. This study proposes a radical pair mechanism based on a flavin-superoxide radical pair to explain the modulation of ROS production and the attenuation of adult hippocampal neurogenesis in a hypomagnetic field. The results of our calculations favor a singlet-born radical pair over a triplet-born radical pair. Our model predicts hypomagnetic field effects on the triplet/singlet yield of comparable strength as the effects observed in experimental studies on adult hippocampal neurogenesis. Our predictions are also in qualitative agreement with experimental results on superoxide concentration and other observed ROS effects. We also predict the effects of applied magnetic fields and oxygen isotopic substitution on adult hippocampal neurogenesis. Our findings strengthen the idea that nature might harness quantum resources in the context of the brain.

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Potential Role of Adult Hippocampal Neurogenesis in Traumatic Brain Injury

Current Medicinal Chemistry ◽

10.2174/0929867328666210923143713 ◽

2021 ◽

Vol 28 ◽

Author(s):

Lucas Alexandre Santos Marzano ◽

Fabyolla Lúcia Macedo de Castro ◽

Caroline Amaral Machado ◽

João Luís Vieira Monteiro de Barros ◽

Thiago Macedo e Cordeiro ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Clinical Studies ◽

Molecular Mechanisms ◽

Hippocampal Neurogenesis ◽

Cognitive Outcomes ◽

Adult Hippocampal Neurogenesis ◽

The Brain

: Traumatic brain injury (TBI) is a serious cause of disability and death among young and adult individuals, displaying complex pathophysiology including cellular and molecular mechanisms that are not fully elucidated. Many experimental and clinical studies investigated the potential relationship between TBI and the process by which neurons are formed in the brain, known as neurogenesis. Currently, there are no available treatments for TBI’s long-term consequences being the search for novel therapeutic targets, a goal of highest scientific and clinical priority. Some studies evaluated the benefits of treatments aimed at improving neurogenesis in TBI. In this scenario, herein, we reviewed current pre-clinical studies that evaluated different approaches to improving neurogenesis after TBI while achieving better cognitive outcomes, which may consist in interesting approaches for future treatments.

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Long-Term Overconsumption of Sugar Starting at Adolescence Produces Persistent Hyperactivity and Neurocognitive Deficits in Adulthood

Frontiers in Neuroscience ◽

10.3389/fnins.2021.670430 ◽

2021 ◽

Vol 15 ◽

Author(s):

Kate Beecher ◽

Ignatius Alvarez Cooper ◽

Joshua Wang ◽

Shaun B. Walters ◽

Fatemeh Chehrehasa ◽

...

Keyword(s):

Dietary Habits ◽

Hippocampal Neurogenesis ◽

Neurocognitive Deficits ◽

Long Term Effects ◽

Sugar Consumption ◽

Food And Beverages ◽

Increased Risk ◽

Newborn Neurons ◽

Dependent Learning

Sugar has become embedded in modern food and beverages. This has led to overconsumption of sugar in children, adolescents, and adults, with more than 60 countries consuming more than four times (>100 g/person/day) the WHO recommendations (25 g/person/day). Recent evidence suggests that obesity and impulsivity from poor dietary habits leads to further overconsumption of processed food and beverages. The long-term effects on cognitive processes and hyperactivity from sugar overconsumption, beginning at adolescence are not known. Using a well-validated mouse model of sugar consumption, we found that long-term sugar consumption, at a level that significantly augments weight gain, elicits an abnormal hyperlocomotor response to novelty and alters both episodic and spatial memory. Our results are similar to those reported in attention deficit and hyperactivity disorders. The deficits in hippocampal-dependent learning and memory were accompanied by altered hippocampal neurogenesis, with an overall decrease in the proliferation and differentiation of newborn neurons within the dentate gyrus. This suggests that long-term overconsumption of sugar, as that which occurs in the Western Diet might contribute to an increased risk of developing persistent hyperactivity and neurocognitive deficits in adulthood.

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Estrogenic Regulation of Hippocampal Neurogenesis Throughout the Lifespan

Estrogens and Memory ◽

10.1093/oso/9780190645908.003.0016 ◽

2020 ◽

pp. 253-281

Author(s):

Shunya Yagi ◽

Rand S. Eid ◽

Wansu Qiu ◽

Paula Duarte-Guterman ◽

Liisa A. M. Galea

Keyword(s):

Steroid Hormones ◽

Cognitive Training ◽

Adult Female ◽

Ovarian Hormones ◽

Hippocampal Neurogenesis ◽

Adult Hippocampal Neurogenesis ◽

Maternal Experience ◽

Number Of Factors ◽

Estrogenic Regulation

Neurogenesis in the hippocampus exists across a number of species, including humans. Steroid hormones, such as estrogens, modulate neurogenesis dependent on age, reproductive experience and sex. Findings are discussed in the chapter with reference to how neurogenesis in the hippocampus is related to learning and memory. Natural fluctuations in ovarian hormones or removal of ovaries modulate neurogenesis in the short term but not in the long term. Maternal experience has long-lasting effects on neurogenesis in the hippocampus. Acute estrogens increase proliferation in adult female rodents, but influence survival of new neurons dependent on a number of factors including sex, cognitive training, type of estrogen, and whether or not cells were produced under estrogens. This chapter outlines findings indicating that estrogens can be strong modulators of adult hippocampal neurogenesis, which may have implications for disorders involving hippocampal dysfunction that target women.

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Acute and Fractionated Exposure to High-LET56Fe HZE-Particle Radiation Both Result in Similar Long-Term Deficits in Adult Hippocampal Neurogenesis

Radiation Research ◽

10.1667/rr13480.1 ◽

2013 ◽

Vol 180 (6) ◽

pp. 658-667 ◽

Cited By ~ 37

Author(s):

Phillip D. Rivera ◽

Hung-Ying Shih ◽

Junie A. LeBlanc ◽

Mara G. Cole ◽

Wellington Z. Amaral ◽

...

Keyword(s):

Hippocampal Neurogenesis ◽

Adult Hippocampal Neurogenesis ◽

Particle Radiation

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Correction: Long-Term Mild, rather than Intense, Exercise Enhances Adult Hippocampal Neurogenesis and Greatly Changes the Transcriptomic Profile of the Hippocampus

PLoS ONE ◽

10.1371/journal.pone.0133089 ◽

2015 ◽

Vol 10 (7) ◽

pp. e0133089 ◽

Cited By ~ 3

Author(s):

Koshiro Inoue ◽

Masahiro Okamoto ◽

Junko Shibato ◽

Min Chul Lee ◽

Takashi Matsui ◽

...

Keyword(s):

Hippocampal Neurogenesis ◽

Adult Hippocampal Neurogenesis ◽

Intense Exercise ◽

Transcriptomic Profile

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Adult Hippocampal Neurogenesis in Different Taxonomic Groups: Possible Functional Similarities and Striking Controversies

Cells ◽

10.3390/cells8020125 ◽

2019 ◽

Vol 8 (2) ◽

pp. 125 ◽

Cited By ~ 19

Author(s):

Marcus Augusto-Oliveira ◽

Gabriela Arrifano ◽

João Malva ◽

Maria Crespo-Lopez

Keyword(s):

Cognitive Processes ◽

Adult Neurogenesis ◽

Spatial Navigation ◽

Absolute Number ◽

Hippocampal Neurogenesis ◽

Adult Hippocampal Neurogenesis ◽

Consolidation Process ◽

Apparent Reduction ◽

Taxonomic Groups ◽

Intense Debate

Adult neurogenesis occurs in many species, from fish to mammals, with an apparent reduction in the number of both neurogenic zones and new neurons inserted into established circuits with increasing brain complexity. Although the absolute number of new neurons is high in some species, the ratio of these cells to those already existing in the circuit is low. Continuous replacement/addition plays a role in spatial navigation (migration) and other cognitive processes in birds and rodents, but none of the literature relates adult neurogenesis to spatial navigation and memory in primates and humans. Some models developed by computational neuroscience attribute a high weight to hippocampal adult neurogenesis in learning and memory processes, with greater relevance to pattern separation. In contrast to theories involving neurogenesis in cognitive processes, absence/rarity of neurogenesis in the hippocampus of primates and adult humans was recently suggested and is under intense debate. Although the learning process is supported by plasticity, the retention of memories requires a certain degree of consolidated circuitry structures, otherwise the consolidation process would be hampered. Here, we compare and discuss hippocampal adult neurogenesis in different species and the inherent paradoxical aspects.

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