Erin Gibson

All Publications

• Precise timing of audiovisual stimulation conquers chemobrain. Trends in cancer Mehl, L. C., Gibson, E. M. 2024

  Abstract

  In a recent study, Kim et al. utilized gamma entrainment using sensory stimuli (GENUS) to rescue cognitive impairment and glial dysregulation associated with cisplatin and methotrexate chemotherapy, specifically when applied both throughout and after chemotherapy administration. GENUS provides a time-dependent, non-invasive method for treating chemobrain, with broader implications for resolving neurodegenerative neuroinflammation.

  View details for DOI 10.1016/j.trecan.2024.04.002

  View details for PubMedID 38644103

• Oligodendrocytes: Myelination, Plasticity, and Axonal Support. Cold Spring Harbor perspectives in biology Simons, M., Gibson, E. M., Nave, K. A. 2024

  Abstract

  The myelination of axons has evolved to enable fast and efficient transduction of electrical signals in the vertebrate nervous system. Acting as an electric insulator, the myelin sheath is a multilamellar membrane structure around axonal segments generated by the spiral wrapping and subsequent compaction of oligodendroglial plasma membranes. These oligodendrocytes are metabolically active and remain functionally connected to the subjacent axon via cytoplasmic-rich myelinic channels for movement of metabolites and macromolecules to and from the internodal periaxonal space under the myelin sheath. Increasing evidence indicates that oligodendrocyte numbers, specifically in the forebrain, and myelin as a dynamic cellular compartment can both respond to physiological demands, collectively referred to as adaptive myelination. This review summarizes our current understanding of how myelin is generated, how its function is dynamically regulated, and how oligodendrocytes support the long-term integrity of myelinated axons.

  View details for DOI 10.1101/cshperspect.a041359

  View details for PubMedID 38621824

• Next Directions in the Neuroscience of Cancers Arising outside the CNS. Cancer discovery Amit, M., Anastasaki, C., Dantzer, R., Demir, I. E., Deneen, B., Dixon, K. O., Egeblad, M., Gibson, E. M., Hervey-Jumper, S. L., Hondermarck, H., Magnon, C., Monje, M., Na'ara, S., Pan, Y., Repasky, E. A., Scheff, N. N., Sloan, E. K., Talbot, S., Tracey, K. J., Trotman, L. C., Valiente, M., Van Aelst, L., Venkataramani, V., Venkatesh, H. S., Vermeer, P. D., Winkler, F., Wong, R. J., Gutmann, D. H., Borniger, J. C. 2024; 14 (4): 669-673

  Abstract

  The field of cancer neuroscience has begun to define the contributions of nerves to cancer initiation and progression; here, we highlight the future directions of basic and translational cancer neuroscience for malignancies arising outside of the central nervous system.

  View details for DOI 10.1158/2159-8290.CD-23-1495

  View details for PubMedID 38571430

• Review: therapeutic approaches for circadian modulation of the glioma microenvironment. Frontiers in oncology Nettnin, E. A., Nguyen, T., Arana, S., Barros Guinle, M. I., Garcia, C. A., Gibson, E. M., Prolo, L. M. 2023; 13: 1295030

  Abstract

  High-grade gliomas are malignant brain tumors that are characteristically hard to treat because of their nature; they grow quickly and invasively through the brain tissue and develop chemoradiation resistance in adults. There is also a distinct lack of targeted treatment options in the pediatric population for this tumor type to date. Several approaches to overcome therapeutic resistance have been explored, including targeted therapy to growth pathways (ie. EGFR and VEGF inhibitors), epigenetic modulators, and immunotherapies such as Chimeric Antigen Receptor T-cell and vaccine therapies. One new promising approach relies on the timing of chemotherapy administration based on intrinsic circadian rhythms. Recent work in glioblastoma has demonstrated temporal variations in chemosensitivity and, thus, improved survival based on treatment time of day. This may be due to intrinsic rhythms of the glioma cells, permeability of the blood brain barrier to chemotherapy agents, the tumor immune microenvironment, or another unknown mechanism. We review the literature to discuss chronotherapeutic approaches to high-grade glioma treatment, circadian regulation of the immune system and tumor microenvironment in gliomas. We further discuss how these two areas may be combined to temporally regulate and/or improve the effectiveness of immunotherapies.

  View details for DOI 10.3389/fonc.2023.1295030

  View details for PubMedID 38173841

  View details for PubMedCentralID PMC10762863

• CIRCADIAN REGULATION OF NEUROINFLAMMATION DRIVING CANCER THERAPY-RELATED COGNITIVE IMPAIRMENT Mehl, L., Gibson, E. OXFORD UNIV PRESS INC. 2023

  View details for Web of Science ID 001115245401023

• BMAL1 loss in oligodendroglia contributes to abnormal myelination and sleep. Neuron Rojo, D., Dal Cengio, L., Badner, A., Kim, S., Sakai, N., Greene, J., Dierckx, T., Mehl, L. C., Eisinger, E., Ransom, J., Arellano-Garcia, C., Gumma, M. E., Soyk, R. L., Lewis, C. M., Lam, M., Weigel, M. K., Damonte, V. M., Yalçın, B., Jones, S. E., Ollila, H. M., Nishino, S., Gibson, E. M. 2023

  Abstract

  Myelination depends on the maintenance of oligodendrocytes that arise from oligodendrocyte precursor cells (OPCs). We show that OPC-specific proliferation, morphology, and BMAL1 are time-of-day dependent. Knockout of Bmal1 in mouse OPCs during development disrupts the expression of genes associated with circadian rhythms, proliferation, density, morphology, and migration, leading to changes in OPC dynamics in a spatiotemporal manner. Furthermore, these deficits translate into thinner myelin, dysregulated cognitive and motor functions, and sleep fragmentation. OPC-specific Bmal1 loss in adulthood does not alter OPC density at baseline but impairs the remyelination of a demyelinated lesion driven by changes in OPC morphology and migration. Lastly, we show that sleep fragmentation is associated with increased prevalence of the demyelinating disorder multiple sclerosis (MS), suggesting a link between MS and sleep that requires further investigation. These findings have broad mechanistic and therapeutic implications for brain disorders that include both myelin and sleep phenotypes.

  View details for DOI 10.1016/j.neuron.2023.08.002

  View details for PubMedID 37657440

• Timing matters: A protective role of astrocyte reactivity in neurodegeneration. Neuron Rojo, D., Gibson, E. M. 2023; 111 (15): 2277-2279

  Abstract

  Sheehan and Nadarajah et al.1 identified that Bmal1 loss from astrocytes induces the expression of BAG3, a macroautophagy chaperone enriched in Alzheimer's disease patients and in disease-associated astrocytes, enhancing the phagocytosis of misfolded proteins and preventing tau and alpha-synuclein pathologies.

  View details for DOI 10.1016/j.neuron.2023.06.014

  View details for PubMedID 37536287

• Beyond the Symptom: The Biology of Fatigue. Sleep Raizen, D. M., Mullington, J., Anaclet, C., Clarke, G., Critchley, H., Dantzer, R., Davis, R., Drew, K. L., Fessel, J., Fuller, P. M., Gibson, E. M., Harrington, M., Lipkin, W. I., Klerman, E. B., Klimas, N., Komaroff, A. L., Koroshetz, W., Krupp, L., Kuppuswamy, A., Lasselin, J., Lewis, L. D., Magistretti, P. J., Matos, H. Y., Miaskowski, C., Miller, A. H., Nath, A., Nedergaard, M., Opp, M. R., Ritchie, M. D., Rogulja, D., Rolls, A., Salamone, J. D., Saper, C., Whittemore, V., Wylie, G., Younger, J., Zee, P. C., Heller, H. C. 2023

  Abstract

  A workshop titled "Beyond the Symptom: The Biology of Fatigue" was held virtually September 27-28, 2021. It was jointly organized by the Sleep Research Society and the Neurobiology of Fatigue Working Group of the NIH Blueprint Neuroscience Research Program. For access to the presentations and video recordings, see: https : //neuroscienceblueprint.nih.gov/about/event/beyond-symptom-biology-fatigue. The goals of this workshop were to bring together clinicians and scientists who use a variety of research approaches to understand fatigue in multiple conditions and to identify key gaps in our understanding of the biology of fatigue. This workshop summary distills key issues discussed in this workshop and provides a list of promising directions for future research on this topic. We do not attempt to provide a comprehensive review of the state of our understanding of fatigue, nor to provide a comprehensive reprise of the many excellent presentations. Rather, our goal is to highlight key advances and to focus on questions and future approaches to answering them.

  View details for DOI 10.1093/sleep/zsad069

  View details for PubMedID 37224457

• Circadian Control of Glial Cell Homeodynamics. Journal of biological rhythms Rojo, D., Badner, A., Gibson, E. M. 2022: 7487304221120966

  Abstract

  The molecular mechanisms that maintain circadian rhythms in mammalian as well as non-mammalian systems are well documented in neuronal populations but comparatively understudied in glia. Glia are highly dynamic in form and function, and the circadian clock provides broad dynamic ranges for the maintenance of this homeostasis, thus glia are key to understanding the role of circadian biology in brain function. Here, we highlight the implications of the molecular circadian clock on the homeodynamic nature of glia, underscoring the current gap in understanding the role of the circadian system in oligodendroglia lineage cells and subsequent myelination. Through this perspective, we will focus on the intersection of circadian and glial biology and how it interfaces with global circadian rhythm maintenance associated with normative and aberrant brain function.

  View details for DOI 10.1177/07487304221120966

  View details for PubMedID 36068711

• Microglia in brain development and regeneration. Development (Cambridge, England) Mehl, L. C., Manjally, A. V., Bouadi, O., Gibson, E. M., Leng Tay, T. 2022; 149 (8)

  Abstract

  It has recently emerged that microglia, the tissue-resident macrophages of the central nervous system, play significant non-innate immune roles to support the development, maintenance, homeostasis and repair of the brain. Apart from being highly specialized brain phagocytes, microglia modulate the development and functions of neurons and glial cells through both direct and indirect interactions. Thus, recognizing the elements that influence the homeostasis and heterogeneity of microglia in normal brain development is crucial to understanding the mechanisms that lead to early disease pathogenesis of neurodevelopmental disorders. In this Review, we discuss recent studies that have elucidated the physiological development of microglia and summarize our knowledge of their non-innate immune functions in brain development and tissue repair.

  View details for DOI 10.1242/dev.200425

  View details for PubMedID 35502782

• NF1 mutation drives neuronalactivity-dependent initiation of optic glioma. Nature Pan, Y., Hysinger, J. D., Barron, T., Schindler, N. F., Cobb, O., Guo, X., Yalcin, B., Anastasaki, C., Mulinyawe, S. B., Ponnuswami, A., Scheaffer, S., Ma, Y., Chang, K., Xia, X., Toonen, J. A., Lennon, J. J., Gibson, E. M., Huguenard, J. R., Liau, L. M., Goldberg, J. L., Monje, M., Gutmann, D. H. 2021

  Abstract

  Neurons have recently emerged as essential cellular constituents of the tumour microenvironment, and their activity has been shown to increase the growth of a diverse number of solid tumours1. Although the role of neurons in tumour progression has previously been demonstrated2, the importance of neuronal activity to tumour initiation is less clear-particularly in the setting of cancer predisposition syndromes. Fifteen per cent of individuals with theneurofibromatosis1 (NF1) cancer predisposition syndrome (in which tumours arise in close association with nerves) develop low-grade neoplasms of the optic pathway (known as optic pathway gliomas (OPGs)) during early childhood3,4, raising the possibility that postnatal light-induced activity of the optic nerve drives tumour initiation. Here we use an authenticated mouse model of OPG driven by mutations in the neurofibromatosis1 tumour suppressor gene (Nf1)5 to demonstrate that stimulation of optic nerve activity increases optic glioma growth, and that decreasing visual experience via light deprivation prevents tumour formation and maintenance. We show that the initiation of Nf1-driven OPGs (Nf1-OPGs) depends on visual experience during a developmental period in which Nf1-mutant mice are susceptible to tumorigenesis. Germline Nf1 mutation in retinal neurons results in aberrantly increased shedding of neuroligin3 (NLGN3) within the optic nerve in response to retinal neuronal activity. Moreover, genetic Nlgn3 loss or pharmacological inhibition of NLGN3 shedding blocks the formation and progression of Nf1-OPGs. Collectively, our studies establish an obligate role for neuronal activity in the development of some types of brain tumours, elucidate a therapeutic strategy to reduce OPG incidence or mitigate tumour progression, and underscore the role of Nf1mutation-mediated dysregulation of neuronal signalling pathways in mouse models of the NF1 cancer predisposition syndrome.

  View details for DOI 10.1038/s41586-021-03580-6

  View details for PubMedID 34040258

• Microglia in Cancer Therapy-Related Cognitive Impairment. Trends in neurosciences Gibson, E. M., Monje, M. 2021

  Abstract

  Millions of cancer survivors experience a persistent neurological syndrome that includes deficits in memory, attention, information processing, and mental health. Cancer therapy-related cognitive impairment can cause mild to severe disruptions to quality of life for these cancer survivors. Understanding the cellular and molecular underpinnings of this disorder will facilitate new therapeutic strategies aimed at ameliorating these long-lasting impairments. Accumulating evidence suggests that a range of cancer therapies induce persistent activation of the brain's resident immune cells, microglia. Cancer therapy-induced microglial activation disrupts numerous mechanisms of neuroplasticity, and emerging findings suggest that this impairment in plasticity is central to cancer therapy-related cognitive impairment. This review explores reactive microglial dysregulation of neural circuit structure and function following cancer therapy.

  View details for DOI 10.1016/j.tins.2021.02.003

  View details for PubMedID 33674135

• How Support of Early Career Researchers Can Reset Science in the Post-COVID19 World. Cell Gibson, E. M., Bennett, F. C., Gillespie, S. M., Guler, A. D., Gutmann, D. H., Halpern, C. H., Kucenas, S. C., Kushida, C. A., Lemieux, M., Liddelow, S., Macauley, S. L., Li, Q., Quinn, M. A., Roberts, L. W., Saligrama, N., Taylor, K. R., Venkatesh, H. S., Yalcin, B., Zuchero, J. B. 2020

  Abstract

  The COVID19 crisis has magnified the issues plaguing academic science, but it has also provided the scientific establishment with an unprecedented opportunity to reset. Shoring up the foundation of academic science will require a concerted effort between funding agencies, universities, and the public to rethink how we support scientists, with a special emphasis on early career researchers.

  View details for DOI 10.1016/j.cell.2020.05.045

  View details for PubMedID 32533917

• Getting personal. Science (New York, N.Y.) Gibson, E. 2020; 367 (6475): 334

  View details for DOI 10.1126/science.367.6475.334

  View details for PubMedID 31949082

• Treating cancer therapy-related cognitive impairment. Nature medicine Gibson, E. M., Monje, M. n. 2020

  View details for DOI 10.1038/s41591-020-1014-1

  View details for PubMedID 32733074

• Emerging mechanistic underpinnings and therapeutic targets for chemotherapy-related cognitive impairment. Current opinion in oncology Gibson, E. M., Monje, M. 2019

  Abstract

  PURPOSE OF REVIEW: Modern innovations in cancer therapy have dramatically increased the number of cancer survivors. An unfortunately frequent side-effect of cancer treatment is enduring neurological impairment. Persistent deficits in attention, concentration, memory, and speed of information processing afflict a substantial fraction of cancer survivors following completion of these life-saving therapies. Here, we highlight chemotherapy-related cognitive impairment (CRCI) and discuss the current understanding of mechanisms underlying CRCI.RECENT FINDINGS: New studies emphasize the deleterious impact of chemotherapeutic agents on glial-glial and neuron-glial interactions that shape the form, function and plasticity of the central nervous system. An emerging theme in cancer therapy-related cognitive impairment is therapy-induced microglial activation and consequent dysfunction of both neural precursor cells and mature neural cell types. Recent work has highlighted the complexity of dysregulated intercellular interactions involving oligodendrocyte lineage cells, microglia, astrocytes, and neurons following exposure to traditional cancer therapies such as methotrexate. This new understanding of the mechanistic underpinnings of CRCI has elucidated potential therapeutic interventions, including colony-stimulating factor 1 receptor inhibition, TrkB agonism, and aerobic exercise.SUMMARY: Traditional cancer therapies induce lasting alterations to multiple neural cell types. Therapy-induced microglial activation is a critical component of the cause of CRCI, contributing to dysregulation of numerous processes of neural plasticity. Therapeutic targeting of microglial activation or the consequent dysregulation of neural plasticity mechanisms are emerging.

  View details for DOI 10.1097/CCO.0000000000000578

  View details for PubMedID 31449084

• Loss of Adaptive Myelination Contributes to Methotrexate Chemotherapy-Related Cognitive Impairment. Neuron Geraghty, A. C., Gibson, E. M., Ghanem, R. A., Greene, J. J., Ocampo, A. n., Goldstein, A. K., Ni, L. n., Yang, T. n., Marton, R. M., Paşca, S. P., Greenberg, M. E., Longo, F. M., Monje, M. n. 2019

  Abstract

  Activity-dependent myelination is thought to contribute to adaptive neurological function. However, the mechanisms by which activity regulates myelination and the extent to which myelin plasticity contributes to non-motor cognitive functions remain incompletely understood. Using a mouse model of chemotherapy-related cognitive impairment (CRCI), we recently demonstrated that methotrexate (MTX) chemotherapy induces complex glial dysfunction for which microglial activation is central. Here, we demonstrate that remote MTX exposure blocks activity-regulated myelination. MTX decreases cortical Bdnf expression, which is restored by microglial depletion. Bdnf-TrkB signaling is a required component of activity-dependent myelination. Oligodendrocyte precursor cell (OPC)-specific TrkB deletion in chemotherapy-naive mice results in impaired cognitive behavioral performance. A small-molecule TrkB agonist rescues both myelination and cognitive impairment after MTX chemotherapy. This rescue after MTX depends on intact TrkB expression in OPCs. Taken together, these findings demonstrate a molecular mechanism required for adaptive myelination that is aberrant in CRCI due to microglial activation.

  View details for DOI 10.1016/j.neuron.2019.04.032

  View details for PubMedID 31122677

• How to tackle the childcare-conference conundrum PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Calisi, R. M., Working Grp Mothers Sci 2018; 115 (12): 2845–49

  View details for DOI 10.1073/pnas.1803153115

  View details for Web of Science ID 000427829500033

  View details for PubMedID 29507208

  View details for PubMedCentralID PMC5866621

• Bad wrap: Myelin and myelin plasticity in health and disease DEVELOPMENTAL NEUROBIOLOGY Gibson, E. M., Geraghty, A. C., Monje, M. 2018; 78 (2): 123–35

  Abstract

  Human central nervous system myelin development extends well into the fourth decade of life, and this protracted period underscores the potential for experience to modulate myelination. The concept of myelin plasticity implies adaptability in myelin structure and function in response to experiences during development and beyond. Mounting evidence supports this concept of neuronal activity-regulated changes in myelin-forming cells, including oligodendrocyte precursor cell proliferation, oligodendrogenesis and modulation of myelin microstructure. In healthy individuals, myelin plasticity in associative white matter structures of the brain is implicated in learning and motor function in both rodents and humans. Activity-dependent changes in myelin-forming cells may influence the function of neural networks that depend on the convergence of numerous neural signals on both a temporal and spatial scale. However, dysregulation of myelin plasticity can disadvantageously alter myelin microstructure and result in aberrant circuit function or contribute to pathological cell proliferation. Emerging roles for myelin plasticity in normal neurological function and in disease are discussed. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 123-135, 2018.

  View details for PubMedID 28986960

  View details for PubMedCentralID PMC5788316

• Methotrexate Chemotherapy Induces Persistent Tri-glial Dysregulation that Underlies Chemotherapy-Related Cognitive Impairment. Cell Gibson, E. M., Nagaraja, S. n., Ocampo, A. n., Tam, L. T., Wood, L. S., Pallegar, P. N., Greene, J. J., Geraghty, A. C., Goldstein, A. K., Ni, L. n., Woo, P. J., Barres, B. A., Liddelow, S. n., Vogel, H. n., Monje, M. n. 2018

  Abstract

  Chemotherapy results in a frequent yet poorly understood syndrome of long-term neurological deficits. Neural precursor cell dysfunction and white matter dysfunction are thought to contribute to this debilitating syndrome. Here, we demonstrate persistent depletion of oligodendrocyte lineage cells in humans who received chemotherapy. Developing a mouse model of methotrexate chemotherapy-induced neurological dysfunction, we find a similar depletion of white matter OPCs, increased but incomplete OPC differentiation, and a persistent deficit in myelination. OPCs from chemotherapy-naive mice similarly exhibit increased differentiation when transplanted into the microenvironment of previously methotrexate-exposed brains, indicating an underlying microenvironmental perturbation. Methotrexate results in persistent activation of microglia and subsequent astrocyte activation that is dependent on inflammatory microglia. Microglial depletion normalizes oligodendroglial lineage dynamics, myelin microstructure, and cognitive behavior after methotrexate chemotherapy. These findings indicate that methotrexate chemotherapy exposure is associated with persistent tri-glial dysregulation and identify inflammatory microglia as a therapeutic target to abrogate chemotherapy-related cognitive impairment.

  View details for PubMedID 30528430

• Myelin plasticity in the central nervous system. Neuropharmacology Purger, D., Gibson, E. M., Monje, M. 2016; 110: 563-573

  Abstract

  Myelin sheaths, specialized segments of oligodendrocyte (OL) plasma membranes in the central nervous system (CNS), facilitate fast, saltatory conduction of action potentials down axons. Changes to the fine structure of myelin in a neural circuit, including sheath thickness and internode length (length of myelin segments between nodes of Ranvier), are expected to affect conduction velocity of action potentials. Myelination of the mammalian CNS occurs in a stereotyped, progressive pattern and continues well into adulthood in humans. Recent evidence from zebrafish, rodents, non-human primates, and humans suggests that myelination may be sensitive to experiences during development and adulthood, and that varying levels of neuronal activity may underlie these experience-dependent changes in myelin and myelin-forming cells. Several cellular, molecular, and epigenetic mechanisms have been investigated as contributors to myelin plasticity. A deeper understanding of myelin plasticity and its underlying mechanisms may provide insights into diseases involving myelin damage or dysregulation. This article is part of the Special Issue entitled 'Oligodendrocytes in Health and Disease'.

  View details for DOI 10.1016/j.neuropharm.2015.08.001

  View details for PubMedID 26282119

• Neuronal Activity Promotes Glioma Growth through Neuroligin-3 Secretion CELL Venkatesh, H. S., Johung, T. B., Caretti, V., Noll, A., Tang, Y., Nagaraja, S., Gibson, E. M., Mount, C. W., Polepalli, J., Mitra, S. S., Woo, P. J., Malenka, R. C., Vogel, H., Bredel, M., Mallick, P., Monje, M. 2015; 161 (4): 803-816

  Abstract

  Active neurons exert a mitogenic effect on normal neural precursor and oligodendroglial precursor cells, the putative cellular origins of high-grade glioma (HGG). By using optogenetic control of cortical neuronal activity in a patient-derived pediatric glioblastoma xenograft model, we demonstrate that active neurons similarly promote HGG proliferation and growth in vivo. Conditioned medium from optogenetically stimulated cortical slices promoted proliferation of pediatric and adult patient-derived HGG cultures, indicating secretion of activity-regulated mitogen(s). The synaptic protein neuroligin-3 (NLGN3) was identified as the leading candidate mitogen, and soluble NLGN3 was sufficient and necessary to promote robust HGG cell proliferation. NLGN3 induced PI3K-mTOR pathway activity and feedforward expression of NLGN3 in glioma cells. NLGN3 expression levels in human HGG negatively correlated with patient overall survival. These findings indicate the important role of active neurons in the brain tumor microenvironment and identify secreted NLGN3 as an unexpected mechanism promoting neuronal activity-regulated cancer growth.

  View details for DOI 10.1016/j.cell.2015.04.012

  View details for PubMedID 25913192

• Neuronal Activity Promotes Oligodendrogenesis and Adaptive Myelination in the Mammalian Brain SCIENCE Gibson, E. M., Purger, D., Mount, C. W., Goldstein, A. K., Lin, G. L., Wood, L. S., Inema, I., Miller, S. E., Bieri, G., Zuchero, J. B., Barres, B. A., Woo, P. J., Vogel, H., Monje, M. 2014; 344 (6183): 487-?

  Abstract

  Myelination of the central nervous system requires the generation of functionally mature oligodendrocytes from oligodendrocyte precursor cells (OPCs). Electrically active neurons may influence OPC function and selectively instruct myelination of an active neural circuit. In this work, we use optogenetic stimulation of the premotor cortex in awake, behaving mice to demonstrate that neuronal activity elicits a mitogenic response of neural progenitor cells and OPCs, promotes oligodendrogenesis, and increases myelination within the deep layers of the premotor cortex and subcortical white matter. We further show that this neuronal activity-regulated oligodendrogenesis and myelination is associated with improved motor function of the corresponding limb. Oligodendrogenesis and myelination appear necessary for the observed functional improvement, as epigenetic blockade of oligodendrocyte differentiation and myelin changes prevents the activity-regulated behavioral improvement.

  View details for DOI 10.1126/science.1252304

  View details for Web of Science ID 000335157700034

  View details for PubMedCentralID PMC4096908

• Effect of cancer therapy on neural stem cells: implications for cognitive function CURRENT OPINION IN ONCOLOGY Gibson, E., Monje, M. 2012; 24 (6): 672-678

  Abstract

  Modern cancer therapies have allowed for a dramatic increase in the survival rates in both children and adults. However, a frequent and unfortunate side-effect of cancer therapy is a long-term decline in neurocognitive function. Specifically, cranial radiation therapy markedly alters memory processes, while chemotherapeutic agents are correlated with deficits in attention, concentration, and speed of information processing. Here, we describe the putative cellular etiologies of cancer treatment-induced cognitive decline, with an emphasis on the role of neural stem and precursor cell dysfunction.New studies highlight the lasting effects of chemotherapy on memory, executive function, attention, and speed of information processing up to 20 years following chemotherapy. Cognitive decrements are associated with decreased white-matter integrity as well as alterations in stem cell function in humans and rodent models of cancer therapy. Genetic polymorphisms may underlie differential sensitivity of certain individuals to the neurological consequences of chemotherapy. Increasing data support the concept that disruption of normal neural stem and precursor cell function is an important causative factor for the cognitive deficits that result from cancer therapy in both children and adults.Further studies are needed to elucidate the role of chemotherapy on cell-intrinsic processes and cellular microenvironments. Further, the effects of the new generation of targeted molecular therapies on neural stem and progenitor cell function remains largely untested. Understanding the mechanisms behind cancer therapy-induced damage to neural stem and precursor cell populations will elucidate neuroprotective and cell replacement strategies aimed at preserving cognition after cancer therapy.

  View details for DOI 10.1097/CCO.0b013e3283571a8e

  View details for Web of Science ID 000310361500011

  View details for PubMedID 22913969

• Experimental 'Jet Lag' Inhibits Adult Neurogenesis and Produces Long-Term Cognitive Deficits in Female Hamsters PLOS ONE Gibson, E. M., Wang, C., Tjho, S., Khattar, N., Kriegsfeld, L. J. 2010; 5 (12): e15267

  Abstract

  Circadian disruptions through frequent transmeridian travel, rotating shift work, and poor sleep hygiene are associated with an array of physical and mental health maladies, including marked deficits in human cognitive function. Despite anecdotal and correlational reports suggesting a negative impact of circadian disruptions on brain function, this possibility has not been experimentally examined.In the present study, we investigated whether experimental 'jet lag' (i.e., phase advances of the light:dark cycle) negatively impacts learning and memory and whether any deficits observed are associated with reductions in hippocampal cell proliferation and neurogenesis. Because insults to circadian timing alter circulating glucocorticoid and sex steroid concentrations, both of which influence neurogenesis and learning/memory, we assessed the contribution of these endocrine factors to any observed alterations. Circadian disruption resulted in pronounced deficits in learning and memory paralleled by marked reductions in hippocampal cell proliferation and neurogenesis. Significantly, deficits in hippocampal-dependent learning and memory were not only seen during the period of the circadian disruption, but also persisted well after the cessation of jet lag, suggesting long-lasting negative consequences on brain function.Together, these findings support the view that circadian disruptions suppress hippocampal neurogenesis via a glucocorticoid-independent mechanism, imposing pronounced and persistent impairments on learning and memory.

  View details for DOI 10.1371/journal.pone.0015267

  View details for Web of Science ID 000284821300019

  View details for PubMedID 21152025

  View details for PubMedCentralID PMC2995744

• Proximate mechanisms driving circadian control of neuroendocrine function: Lessons from the young and old Williams, W. P., Gibson, E. M., Wang, C., Tjho, S., Khattar, N., Bentley, G. E., Tsutsui, K., Kriegsfeld, L. J. OXFORD UNIV PRESS INC. 2009: 519–37

  Abstract

  Circadian rhythms impact a variety of behavioral and physiological functions contributing to longevity and successful reproduction. In their natural environments, individuals of a species are faced with a multitude of challenges and the coordination of internal processes and behavior with external pressures has been hypothesized to be an important target of natural selection. Several lines of evidence from cyanobacteria, Drosophila, and plants provide strong support for an important role of the circadian clock in survival and reproductive success. Similarly in mammals, disruptions in circadian function markedly impact reproduction and lifespan. The present review discusses research outlining the proximate and ultimate mechanisms responsible for the central and peripheral control of the reproductive axis. Because precise temporal coordination of the endocrine system is particularly crucial for reproduction by females, the present overview focuses on the role of circadian timing in this sex.

  View details for DOI 10.1093/icb/icp041

  View details for Web of Science ID 000271946500005

  View details for PubMedID 21665838

• Aging in the circadian system: Considerations for health, disease prevention and longevity Gibson, E. M., Williams, W. P., Kriegsfeld, L. J. PERGAMON-ELSEVIER SCIENCE LTD. 2009: 51–56

  Abstract

  The circadian system orchestrates internal physiology on a daily schedule to promote optimal health and maximize disease prevention. Chronic disruptions in circadian function are associated with an increase in a variety of disease states including, heart disease, ulcers and diabetes. With advanced age, the genes regulating circadian function at the cellular level become disorganized and the ability of the brain clock to entrain to local time diminishes. As a result, aged individuals exhibit a loss of temporal coordination among bodily systems, leading to deficits in homeostasis and sub-optimal functioning. Such disruptions in the circadian system appear to accelerate the aging process and contribute to senescence, with some systems being more vulnerable than others. This review explores aging-associated changes in circadian function and examines evidence linking such alterations to adverse health consequences in late life and promotion of the aging process.

  View details for DOI 10.1016/j.exger.2008.05.007

  View details for Web of Science ID 000262623800009

  View details for PubMedID 18579326

  View details for PubMedCentralID PMC2636858

• Age-related declines in exploratory behavior and markers of hippocampal plasticity are attenuated by prenatal choline supplementation in rats BRAIN RESEARCH Glenn, M. J., Kirby, E. D., Gibson, E. M., Wong-Goodrich, S. J., Mellott, T. J., Blusztajn, J. K., Williams, C. L. 2008; 1237: 110-123

  Abstract

  Supplemental choline in the maternal diet produces a lasting enhancement in memory in offspring that resists age-related decline and is accompanied by neuroanatomical, neurophysiological and neurochemical changes in the hippocampus. The present study was designed to examine: 1) if prenatal choline supplementation alters behaviors that contribute to risk or resilience in cognitive aging, and 2) whether, at old age (25 months), prenatally choline-supplemented rats show evidence of preserved hippocampal plasticity. A longitudinal design was used to look at exploration of an open field, with and without objects, at 1 and 24 months of age in male and female rats whose mothers were fed a diet supplemented with choline (SUP; 5 mg/kg choline chloride) or not supplemented (CON; 1.1 mg/kg choline chloride) on embryonic days 12-17. Aging caused a significant decline in open field exploration that was more pronounced in males but interest in novel objects was maintained in both sexes. Prenatal choline supplementation attenuated, but did not prevent age-related decline in exploration in males and increased object exploration in young females. Following behavioral assessment, rats were euthanized to assess markers of hippocampal plasticity. Aged SUP males and females had more newly proliferated cells in the hippocampal dentate gyrus and protein levels of vascular endothelial growth factor (VEGF) and neurotrophin-3 (NT-3) were significantly elevated in female SUP rats in comparison to all other groups. Taken together, these findings provide the first evidence that prenatal choline supplementation causes changes in exploratory behaviors over the lifespan and preserves some features of hippocampal plasticity that can be seen even at 2 years of age.

  View details for DOI 10.1016/j.brainres.2008.08.049

  View details for Web of Science ID 000260815600013

  View details for PubMedID 18786518

  View details for PubMedCentralID PMC2677022

• Alterations in RFamide-related peptide expression are coordinated with the preovulatory luteinizing hormone surge ENDOCRINOLOGY Gibson, E. M., Humber, S. A., Jain, S., Williams, W. P., Zhao, S., Bentley, G. E., Tsutsui, K., Kriegsfeld, L. J. 2008; 149 (10): 4958–69

  Abstract

  The preovulatory LH surge is triggered when the circadian pacemaker, the bilateral suprachiasmatic nucleus (SCN), stimulates the GnRH system in the presence of high estrogen concentrations (positive feedback). Importantly, during the remainder of the estrous cycle, estradiol inhibits LH release via negative feedback. We have recently documented the presence of a novel mammalian RFamide-related peptide (RFRP), a putative gonadotropin-inhibitory hormone (GnIH), that presumably acts upstream of GnRH to modulate the negative feedback effects of estrogen. The present series of studies used female Syrian hamsters to examine the possibility that, in addition to driving the LH surge positively, the SCN concomitantly coordinates the removal of steroid-mediated RFRP inhibition of the gonadotropic axis to permit the surge. We found that the SCN forms close appositions with RFRP cells, suggesting the possibility for direct temporal control of RFRP activity. During the time of the LH surge, immediate-early gene expression is reduced in RFRP cells, and this temporal regulation is estrogen dependent. To determine whether projections from the SCN regulate the timed reduction in activation of the RFRP system, we exploited the phenomenon of splitting. In split animals in which the SCN are active in antiphase, activation of the RFRP system is asymmetrical. Importantly, this asymmetry is opposite to the state of the GnRH system. Together, these findings point to novel circadian control of the RFRP system and potential participation in the circuitry controlling ovulatory function.

  View details for DOI 10.1210/en.2008-0316

  View details for Web of Science ID 000259400300021

  View details for PubMedID 18566114

  View details for PubMedCentralID PMC2582915

• Prenatal choline availability modulates hippocampal neurogenesis and neurogenic responses to enriching experiences in adult female rats EUROPEAN JOURNAL OF NEUROSCIENCE Glenn, M. J., Gibson, E. M., Kirby, E. D., Mellott, T. J., Blusztajn, J. K., Williams, C. L. 2007; 25 (8): 2473-2482

  Abstract

  Increased dietary intake of choline early in life improves performance of adult rats on memory tasks and prevents their age-related memory decline. Because neurogenesis in the adult hippocampus also declines with age, we investigated whether prenatal choline availability affects hippocampal neurogenesis in adult Sprague-Dawley rats and modifies their neurogenic response to environmental stimulation. On embryonic days (ED) 12-17, pregnant rats ate a choline-supplemented (SUP-5 g/kg), choline sufficient (SFF-1.1 g/kg), or choline-free (DEF) semisynthetic diet. Adult offspring either remained in standard housing or were given 21 daily visits to explore a maze. On the last ten exploration days, all rats received daily injections of 5-bromo-2-deoxyuridine (BrdU, 100 mg/kg). The number of BrdU+ cells was significantly greater in the dentate gyrus in SUP rats compared to SFF or DEF rats. While maze experience increased the number of BrdU+ cells in SFF rats to the level seen in the SUP rats, this enriching experience did not alter cell proliferation in DEF rats. Similar patterns of cell proliferation were obtained with immunohistochemical staining for neuronal marker doublecortin, confirming that diet and exploration affected hippocampal neurogenesis. Moreover, hippocampal levels of the brain-derived neurotrophic factor (BDNF) were increased in SUP rats as compared to SFF and DEF animals. We conclude that prenatal choline intake has enduring effects on adult hippocampal neurogenesis, possibly via up-regulation of BDNF levels, and suggest that these alterations of neurogenesis may contribute to the mechanism of life-long changes in cognitive function governed by the availability of choline during gestation.

  View details for DOI 10.1111/j.1460-9568.2007.05505.x

  View details for Web of Science ID 000245742300020

  View details for PubMedID 17445242

  View details for PubMedCentralID PMC2435208