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Daniel JM, Lindsey SH, Mostany R, Schrader LA, Zsombok A. Cardiometabolic health, menopausal estrogen therapy and the brain: How effects of estrogens diverge in healthy and unhealthy preclinical models of aging. Front Neuroendocrinol 2023; 70:101068. [PMID: 37061205 PMCID: PMC10725785 DOI: 10.1016/j.yfrne.2023.101068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/23/2023] [Accepted: 04/10/2023] [Indexed: 04/17/2023]
Abstract
Research in preclinical models indicates that estrogens are neuroprotective and positively impact cognitive aging. However, clinical data are equivocal as to the benefits of menopausal estrogen therapy to the brain and cognition. Pre-existing cardiometabolic disease may modulate mechanisms by which estrogens act, potentially reducing or reversing protections they provide against cognitive decline. In the current review we propose mechanisms by which cardiometabolic disease may alter estrogen effects, including both alterations in actions directly on brain memory systems and actions on cardiometabolic systems, which in turn impact brain memory systems. Consideration of mechanisms by which estrogen administration can exert differential effects dependent upon health phenotype is consistent with the move towards precision or personalized medicine, which aims to determine which treatment interventions will work for which individuals. Understanding effects of estrogens in both healthy and unhealthy models of aging is critical to optimizing the translational link between preclinical and clinical research.
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Affiliation(s)
- Jill M Daniel
- Department of Psychology and Brain Institute, Tulane University, New Orleans, LA, United States.
| | - Sarah H Lindsey
- Department of Pharmacology and Brain Institute, Tulane University, New Orleans, LA, United States
| | - Ricardo Mostany
- Department of Pharmacology and Brain Institute, Tulane University, New Orleans, LA, United States
| | - Laura A Schrader
- Department of Cell & Molecular Biology and Brain Institute, Tulane University, New Orleans, LA, United States
| | - Andrea Zsombok
- Department of Physiology and Brain Institute, Tulane University, New Orleans, LA, United States
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Kuang H, Liu T, Jiao C, Wang J, Wu S, Wu J, Peng S, Davidson AM, Zeng SX, Lu H, Mostany R. Genetic Deficiency of p53 Leads to Structural, Functional, and Synaptic Deficits in Primary Somatosensory Cortical Neurons of Adult Mice. Front Mol Neurosci 2022; 15:871974. [PMID: 35465090 PMCID: PMC9021533 DOI: 10.3389/fnmol.2022.871974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
The tumor suppressor p53 plays a crucial role in embryonic neuron development and neurite growth, and its involvement in neuronal homeostasis has been proposed. To better understand how the lack of the p53 gene function affects neuronal activity, spine development, and plasticity, we examined the electrophysiological and morphological properties of layer 5 (L5) pyramidal neurons in the primary somatosensory cortex barrel field (S1BF) by using in vitro whole-cell patch clamp and in vivo two-photon imaging techniques in p53 knockout (KO) mice. We found that the spiking frequency, excitatory inputs, and sag ratio were decreased in L5 pyramidal neurons of p53KO mice. In addition, both in vitro and in vivo morphological analyses demonstrated that dendritic spine density in the apical tuft is decreased in L5 pyramidal neurons of p53KO mice. Furthermore, chronic imaging showed that p53 deletion decreased dendritic spine turnover in steady-state conditions, and prevented the increase in spine turnover associated with whisker stimulation seen in wildtype mice. In addition, the sensitivity of whisker-dependent texture discrimination was impaired in p53KO mice compared with wildtype controls. Together, these results suggest that p53 plays an important role in regulating synaptic plasticity by reducing neuronal excitability and the number of excitatory synapses in S1BF.
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Affiliation(s)
- Haixia Kuang
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Tao Liu
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, United States
- *Correspondence: Tao Liu Hua Lu Ricardo Mostany
| | - Cui Jiao
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jianmei Wang
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Shinan Wu
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jing Wu
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Sicong Peng
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Andrew M. Davidson
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Shelya X. Zeng
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Hua Lu
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, United States
- *Correspondence: Tao Liu Hua Lu Ricardo Mostany
| | - Ricardo Mostany
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, United States
- Tulane Brain Institute, Tulane University, New Orleans, LA, United States
- *Correspondence: Tao Liu Hua Lu Ricardo Mostany
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McIntyre S, Nagi SS, McGlone F, Olausson H. The Effects of Ageing on Tactile Function in Humans. Neuroscience 2021; 464:53-58. [PMID: 33607227 DOI: 10.1016/j.neuroscience.2021.02.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 02/04/2021] [Accepted: 02/09/2021] [Indexed: 12/21/2022]
Abstract
Ageing is accompanied by a steady decline in touch sensitivity and acuity. Conversely, pleasant touch, such as experienced during a caress, is even more pleasant in old age. There are many physiological changes that might explain these perceptual changes, but researchers have not yet identified any specific mechanisms. Here, we review both the perceptual and structural changes to the touch system that are associated with ageing. The structural changes include reduced elasticity of the skin in older people, as well as reduced numbers and altered morphology of skin tactile receptors. Effects of ageing on the peripheral and central nervous systems include demyelination, which affects the timing of neural signals, as well as reduced numbers of peripheral nerve fibres. The ageing brain also undergoes complex changes in blood flow, metabolism, plasticity, neurotransmitter function, and, for touch, the body map in primary somatosensory cortex. Although several studies have attempted to find a direct link between perceptual and structural changes, this has proved surprisingly elusive. We also highlight the need for more evidence regarding age-related changes in peripheral nerve function in the hairy skin, as well as the social and emotional aspects of touch.
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Affiliation(s)
- Sarah McIntyre
- Center for Social and Affective Neuroscience, Linköping University, Sweden.
| | - Saad S Nagi
- Center for Social and Affective Neuroscience, Linköping University, Sweden
| | - Francis McGlone
- Research Centre in Brain & Behaviour, Liverpool John Moores University, Liverpool, United Kingdom
| | - Håkan Olausson
- Center for Social and Affective Neuroscience, Linköping University, Sweden
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Yap K, Drakew A, Smilovic D, Rietsche M, Paul MH, Vuksic M, Del Turco D, Deller T. The actin-modulating protein synaptopodin mediates long-term survival of dendritic spines. eLife 2020; 9:e62944. [PMID: 33275099 PMCID: PMC7717903 DOI: 10.7554/elife.62944] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/14/2020] [Indexed: 12/15/2022] Open
Abstract
Large spines are stable and important for memory trace formation. The majority of large spines also contains synaptopodin (SP), an actin-modulating and plasticity-related protein. Since SP stabilizes F-actin, we speculated that the presence of SP within large spines could explain their long lifetime. Indeed, using 2-photon time-lapse imaging of SP-transgenic granule cells in mouse organotypic tissue cultures we found that spines containing SP survived considerably longer than spines of equal size without SP. Of note, SP-positive (SP+) spines that underwent pruning first lost SP before disappearing. Whereas the survival time courses of SP+ spines followed conditional two-stage decay functions, SP-negative (SP-) spines and all spines of SP-deficient animals showed single-phase exponential decays. This was also the case following afferent denervation. These results implicate SP as a major regulator of long-term spine stability: SP clusters stabilize spines, and the presence of SP indicates spines of high stability.
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Affiliation(s)
- Kenrick Yap
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Alexander Drakew
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Dinko Smilovic
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
- Croatian Institute for Brain Research, School of Medicine, University of ZagrebZagrebCroatia
| | - Michael Rietsche
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Mandy H Paul
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Mario Vuksic
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
- Croatian Institute for Brain Research, School of Medicine, University of ZagrebZagrebCroatia
| | - Domenico Del Turco
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
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Popescu IR, Le KQ, Ducote AL, Li JE, Leland AE, Mostany R. Increased intrinsic excitability and decreased synaptic inhibition in aged somatosensory cortex pyramidal neurons. Neurobiol Aging 2020; 98:88-98. [PMID: 33249377 DOI: 10.1016/j.neurobiolaging.2020.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/02/2020] [Accepted: 10/08/2020] [Indexed: 10/23/2022]
Abstract
Sensorimotor performance declines during advanced age, partially due to deficits in somatosensory acuity. Cortical receptive field expansion contributes to somatosensory deficits, suggesting increased excitability or decreased inhibition in primary somatosensory cortex (S1) pyramidal neurons. To ascertain changes in excitability and inhibition, we measured both properties in neurons from vibrissal S1 in brain slices from young and aged mice. Because adapting and non-adapting neurons-the principal pyramidal types in layer 5 (L5)-differ in intrinsic properties and inhibitory inputs, we determined age-dependent changes according to neuron type. We found an age-dependent increase in intrinsic excitability in adapting neurons, caused by a decrease in action potential threshold. Surprisingly, in non-adapting neurons we found both an increase in excitability caused by increased input resistance, and a decrease in synaptic inhibition. Spike frequency adaptation, already small in non-adapting neurons, was further reduced by aging, whereas sag, a manifestation of Ih, was increased. Therefore, aging caused both decreased inhibition and increased intrinsic excitability, but these effects were specific to pyramidal neuron type.
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Affiliation(s)
- Ion R Popescu
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA.
| | - Kathy Q Le
- Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | - Alexis L Ducote
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | - Jennifer E Li
- Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | | | - Ricardo Mostany
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA
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Cheyne JE, Montgomery JM. The cellular and molecular basis of in vivo synaptic plasticity in rodents. Am J Physiol Cell Physiol 2020; 318:C1264-C1283. [PMID: 32320288 DOI: 10.1152/ajpcell.00416.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Plasticity within the neuronal networks of the brain underlies the ability to learn and retain new information. The initial discovery of synaptic plasticity occurred by measuring synaptic strength in vivo, applying external stimulation and observing an increase in synaptic strength termed long-term potentiation (LTP). Many of the molecular pathways involved in LTP and other forms of synaptic plasticity were subsequently uncovered in vitro. Over the last few decades, technological advances in recording and imaging in live animals have seen many of these molecular mechanisms confirmed in vivo, including structural changes both pre- and postsynaptically, changes in synaptic strength, and changes in neuronal excitability. A well-studied aspect of neuronal plasticity is the capacity of the brain to adapt to its environment, gained by comparing the brains of deprived and experienced animals in vivo, and in direct response to sensory stimuli. Multiple in vivo studies have also strongly linked plastic changes to memory by interfering with the expression of plasticity and by manipulating memory engrams. Plasticity in vivo also occurs in the absence of any form of external stimulation, i.e., during spontaneous network activity occurring with brain development. However, there is still much to learn about how plasticity is induced during natural learning and how this is altered in neurological disorders.
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Affiliation(s)
- Juliette E Cheyne
- Department of Physiology and Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Johanna M Montgomery
- Department of Physiology and Centre for Brain Research, University of Auckland, Auckland, New Zealand
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Lee CR, Najafizadeh L, Margolis DJ. Investigating learning-related neural circuitry with chronic in vivo optical imaging. Brain Struct Funct 2020; 225:467-480. [PMID: 32006147 DOI: 10.1007/s00429-019-02001-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 12/05/2019] [Indexed: 10/25/2022]
Abstract
Fundamental aspects of brain function, including development, plasticity, learning, and memory, can take place over time scales of days to years. Chronic in vivo imaging of neural activity with cellular resolution is a powerful method for tracking the long-term activity of neural circuits. We review recent advances in our understanding of neural circuit function from diverse brain regions that have been enabled by chronic in vivo cellular imaging. Insight into the neural basis of learning and decision-making, in particular, benefit from the ability to acquire longitudinal data from genetically identified neuronal populations, deep brain areas, and subcellular structures. We propose that combining chronic imaging with further experimental and computational innovations will advance our understanding of the neural circuit mechanisms of brain function.
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Affiliation(s)
- Christian R Lee
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Laleh Najafizadeh
- Department of Electrical and Computer Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - David J Margolis
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA.
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