1
|
Kim SC, Park JY, Hwang EM. Caspase-dependent apoptosis induces reactivation and gliogenesis of astrocytes in adult mice. Front Cell Neurosci 2022; 16:1054956. [DOI: 10.3389/fncel.2022.1054956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 11/15/2022] [Indexed: 12/05/2022] Open
Abstract
Astrocytes play an important role in increasing synaptic plasticity, regulating endogenous homeostasis, and contributing to neuroprotection but become overactivated or apoptotic in persistent neuroinflammatory responses or pathological conditions. Although gliogenesis under these conditions may be essential for neuronal protection, much remains unknown. Here, we generated new conditional transgenic mice (cTg) that can induce apoptosis via Cre-dependent active caspase-3 (taCasp3-2A-TEVp) without pathological conditions. We induced apoptosis of hippocampal CA1 astrocytes in cTg mice using GFAP promoter-driven adeno-associated virus (AAV) containing Cre recombinase. Activated caspase-3 was detected in astrocytes of the hippocampal CA1, and the number of astrocytes decreased sharply at 1 week but recovered at 2 weeks and was maintained until 4 weeks. Nuclear factor 1A (NF1A) mRNA, an important transcription factor for hippocampal reactive astrocytes, was significantly increased only at week 1. Interestingly, all reactive markers (pan, A1, A2) increased despite the decreased number of astrocytes at week 1, and there was no change in monoamine oxidase B (MAOB) observed in astrocytes of animal models of degenerative brain disease. Extensive CA1 astrocyte depletion at week 1 induced cognitive deficits; however, both recovered at weeks 2 and 4. Overall, transient hippocampal astrocyte depletion caused by apoptosis restored cell number and function within 2 weeks and did not induce significant neurotoxicity. Therefore, cTg mice are valuable as an in vivo animal model for studying gliogenesis in multiple regions of the adult brain.
Collapse
|
2
|
Polykretis I, Michmizos KP. The role of astrocytes in place cell formation: A computational modeling study. J Comput Neurosci 2022; 50:505-518. [PMID: 35840871 PMCID: PMC9671849 DOI: 10.1007/s10827-022-00828-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 05/20/2022] [Accepted: 07/12/2022] [Indexed: 11/30/2022]
Abstract
Place cells develop spatially-tuned receptive fields during the early stages of novel environment exploration. The generative mechanism underlying these spatially-selective responses remains largely elusive, but has been associated with theta rhythmicity. An important factor implicating the transformation of silent cells to place cells is a spatially-uniform depolarization that is mediated by a persistent sodium current. This neuronal current is modulated by extracellular calcium concentration, which, in turn, is actively controlled by astrocytes. However, there is no established relationship between the neuronal depolarization and astrocytic activity. To consider this link, we designed a bioplausible computational model of a neuronal-astrocytic network, where astrocytes induced the transient emergence of place fields in silent cells, and accelerated the plasticity-induced consolidation of place cells. Interestingly, theta oscillations emerged naturally at the network level, resulting from the astrocytic modulation of subcellular neuronal properties. Our results suggest that astrocytes participate in spatial mapping and exploration, and further highlight the computational roles of these cells in the brain.
Collapse
Affiliation(s)
- Ioannis Polykretis
- Computational Brain Lab, Department of Computer Science, Rutgers University, New Brunswick, New Jersey, USA
| | - Konstantinos P Michmizos
- Computational Brain Lab, Department of Computer Science, Rutgers University, New Brunswick, New Jersey, USA.
| |
Collapse
|
3
|
Tao XD, Liu ZR, Zhang YQ, Zhang XH. Connexin43 hemichannels contribute to working memory and excitatory synaptic transmission of pyramidal neurons in the prefrontal cortex of rats. Life Sci 2021; 286:120049. [PMID: 34662549 DOI: 10.1016/j.lfs.2021.120049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 10/08/2021] [Accepted: 10/08/2021] [Indexed: 11/30/2022]
Abstract
The gap junction is essential for the communication between astrocytes and neurons by various connexins. Connexin43 hemichannels (Cx43 HCs), one of important subunits of gap junction protein, is highly expressed in astrocytes. It has been demonstrated that Cx43 HCs is involved in synaptic plasticity and learning and memory. However, whether the role of Cx43 HCs in the prefrontal cortex (PFC), a key brain region mediating cognitive and executive functions including working memory, still remains unclear. Here, we investigate that the role of Cx43 HCs in working memory through pharmacological inhibition of Cx43 HCs in the PFC. Gap26, a specific hemichannels blocker for Cx43 HCs, was bilaterally infused into the prelimbic (PrL) area of the PFC and then spatial working memory was examined in delayed alternation task in T-maze. Furthermore, the effect of Gap26 on synaptic transmission of prefrontal pyramidal neurons was examined using whole-cell patch recording in slice containing PFC. The demonstrate that inhibition of prefrontal cortex Cx43 HCs impairs the working memory and excitatory synaptic transmission of PFC neurons, suggesting that Cx43 HCs in the PFC contributes to working memory and excitatory synaptic transmission of neurons in rats.
Collapse
Affiliation(s)
- Xiao-Dong Tao
- Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Zhao-Rui Liu
- Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Yu-Qiu Zhang
- Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Xue-Han Zhang
- Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China.
| |
Collapse
|
4
|
Irwin AB, Bahabry R, Lubin FD. A putative role for lncRNAs in epigenetic regulation of memory. Neurochem Int 2021; 150:105184. [PMID: 34530054 PMCID: PMC8552959 DOI: 10.1016/j.neuint.2021.105184] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 08/29/2021] [Accepted: 08/31/2021] [Indexed: 12/12/2022]
Abstract
The central dogma of molecular genetics is defined as encoded genetic information within DNA, transcribed into messenger RNA, which contain the instructions for protein synthesis, thus imparting cellular functionality and ultimately life. This molecular genetic theory has given birth to the field of neuroepigenetics, and it is now well established that epigenetic regulation of gene transcription is critical to the learning and memory process. In this review, we address a potential role for a relatively new player in the field of epigenetic crosstalk - long non-coding RNAs (lncRNAs). First, we briefly summarize epigenetic mechanisms in memory formation and examine what little is known about the emerging role of lncRNAs during this process. We then focus discussions on how lncRNAs interact with epigenetic mechanisms to control transcriptional programs under various conditions in the brain, and how this may be applied to regulation of gene expression necessary for memory formation. Next, we explore how epigenetic crosstalk in turn serves to regulate expression of various individual lncRNAs themselves. To highlight the importance of further exploring the role of lncRNA in epigenetic regulation of gene expression, we consider the significant relationship between lncRNA dysregulation and declining memory reserve with aging, Alzheimer's disease, and epilepsy, as well as the promise of novel therapeutic interventions. Finally, we conclude with a discussion of the critical questions that remain to be answered regarding a role for lncRNA in memory.
Collapse
Affiliation(s)
- Ashleigh B Irwin
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Rudhab Bahabry
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Farah D Lubin
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
| |
Collapse
|
5
|
Perez DM. α 1-Adrenergic Receptors in Neurotransmission, Synaptic Plasticity, and Cognition. Front Pharmacol 2020; 11:581098. [PMID: 33117176 PMCID: PMC7553051 DOI: 10.3389/fphar.2020.581098] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/11/2020] [Indexed: 12/14/2022] Open
Abstract
α1-adrenergic receptors are G-Protein Coupled Receptors that are involved in neurotransmission and regulate the sympathetic nervous system through binding and activating the neurotransmitter, norepinephrine, and the neurohormone, epinephrine. There are three α1-adrenergic receptor subtypes (α1A, α1B, α1D) that are known to play various roles in neurotransmission and cognition. They are related to two other adrenergic receptor families that also bind norepinephrine and epinephrine, the β- and α2-, each with three subtypes (β1, β2, β3, α2A, α2B, α2C). Previous studies assessing the roles of α1-adrenergic receptors in neurotransmission and cognition have been inconsistent. This was due to the use of poorly-selective ligands and many of these studies were published before the characterization of the cloned receptor subtypes and the subsequent development of animal models. With the availability of more-selective ligands and the development of animal models, a clearer picture of their role in cognition and neurotransmission can be assessed. In this review, we highlight the significant role that the α1-adrenergic receptor plays in regulating synaptic efficacy, both short and long-term synaptic plasticity, and its regulation of different types of memory. We will also present evidence that the α1-adrenergic receptors, and particularly the α1A-adrenergic receptor subtype, are a potentially good target to treat a wide variety of neurological conditions with diminished cognition.
Collapse
Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, United States
| |
Collapse
|
6
|
Hassanpoor H, Saidi M. An investigation into the effective role of astrocyte in the hippocampus pattern separation process: A computational modeling study. J Theor Biol 2020; 487:110114. [PMID: 31836505 DOI: 10.1016/j.jtbi.2019.110114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 11/15/2019] [Accepted: 12/09/2019] [Indexed: 11/29/2022]
Abstract
A physiologically realistic three layer neuron-astrocyte network model is used to evaluate the biological mechanism in pattern separation. The innovative feature of the model is the use of a combination of three elements: neuron, interneuron and astrocyte. In the input layer, a pyramidal neuron receives input patterns from stimulus current, while in the middle layer there are two pyramidal neurons coupled with two inhibitory interneurons and an astrocyte. Finally, in the third layer, a pyramidal neuron produces the output of the model by integrating the output of two neurons from the middle layer resulting from inhibitory and excitatory connections among neurons, interneurons and the astrocyte. Results of computer simulations show that the neuron-astrocyte network within the hippocampal dentate gyrus can generate diverse, complex and different output patterns to given inputs. It is concluded that astrocytes within the dentate gyrus play an important role in the pattern separation process.
Collapse
Affiliation(s)
- Hossein Hassanpoor
- Department of Cognitive Science, Dade Pardazi, Shenakht Mehvar, Atynegar (DSA) Institute, Tehran, Iran.
| | - Maryam Saidi
- Department of Cognitive Science, Dade Pardazi, Shenakht Mehvar, Atynegar (DSA) Institute, Tehran, Iran
| |
Collapse
|
7
|
Bondan EF, Cardoso CV, Martins MDFM, Otton R. Memory impairments and increased GFAP expression in hippocampal astrocytes following hypercaloric diet in rats. ARQUIVOS DE NEURO-PSIQUIATRIA 2019; 77:601-608. [DOI: 10.1590/0004-282x20190091] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 05/02/2019] [Indexed: 01/11/2023]
Abstract
ABSTRACT Objective: Hypothalamic inflammation and glial fibrillary acidic protein (GFAP) overexpression in astrocytes are well described in obese animals, as are some cognitive and memory deficits. As the hippocampus plays important roles in the consolidation of information, this investigation aimed to observe the memory function and the astrocyte expression of GFAP in the hippocampus of rats that received either a hypercaloric or a normocaloric diet. Methods: Adult male Wistar rats received a high-fat (cafeteria) or a standard diet for 60 days. On the 61st day, the rats were submitted to the novel object recognition (NOR) test at three and 24 hours after the first contact with objects, to assess short-term and long-term memory, respectively. Thereafter, the rats were euthanized and their brains were collected for GFAP immunohistochemical investigation in the hippocampus (CA1, CA2, CA3 areas) and hypothalamus (periventricular and arcuate nuclei). Astrocytic reactivity was assessed by morphometry. Different white adipose tissue depots and brown adipose tissue were weighed to calculate the adiposity index. Results: The hypercaloric diet increased body weight gain, adiposity index, white adipose tissue weight (epididymal, subcutaneous and retroperitoneal) and brown adipose tissue weight. Rats fed with the hypercaloric diet showed short-term and long-term memory impairments in the NOR test, as well as increased GFAP expression in astrocytes from all analyzed hypothalamic and hippocampal areas. Conclusion: This astrogliosis suggests that the neuroinflammatory response also occurs in the hippocampus and may be involved in the memory losses observed in obese/overweight animals.
Collapse
|
8
|
El Khiat A, Tamegart L, Draoui A, El Fari R, Sellami S, Rais H, El Hiba O, Gamrani H. Kinetic deterioration of short memory in rat with acute hepatic encephalopathy: Involvement of astroglial and neuronal dysfunctions. Behav Brain Res 2019; 367:201-209. [DOI: 10.1016/j.bbr.2019.03.046] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/25/2019] [Accepted: 03/26/2019] [Indexed: 02/07/2023]
|
9
|
Xu C, Li Q, Efimova O, He L, Tatsumoto S, Stepanova V, Oishi T, Udono T, Yamaguchi K, Shigenobu S, Kakita A, Nawa H, Khaitovich P, Go Y. Human-specific features of spatial gene expression and regulation in eight brain regions. Genome Res 2018; 28:1097-1110. [PMID: 29898898 PMCID: PMC6071643 DOI: 10.1101/gr.231357.117] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 06/04/2018] [Indexed: 01/22/2023]
Abstract
Molecular maps of the human brain alone do not inform us of the features unique to humans. Yet, the identification of these features is important for understanding both the evolution and nature of human cognition. Here, we approached this question by analyzing gene expression and H3K27ac chromatin modification data collected in eight brain regions of humans, chimpanzees, gorillas, a gibbon, and macaques. An analysis of spatial transcriptome trajectories across eight brain regions in four primate species revealed 1851 genes showing human-specific transcriptome differences in one or multiple brain regions, in contrast to 240 chimpanzee-specific differences. More than half of these human-specific differences represented elevated expression of genes enriched in neuronal and astrocytic markers in the human hippocampus, whereas the rest were enriched in microglial markers and displayed human-specific expression in several frontal cortical regions and the cerebellum. An analysis of the predicted regulatory interactions driving these differences revealed the role of transcription factors in species-specific transcriptome changes, and epigenetic modifications were linked to spatial expression differences conserved across species.
Collapse
Affiliation(s)
- Chuan Xu
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Qian Li
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Olga Efimova
- Skolkovo Institute of Science and Technology, Moscow 143026, Russia
| | - Liu He
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Shoji Tatsumoto
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi 4448585, Japan
| | - Vita Stepanova
- Skolkovo Institute of Science and Technology, Moscow 143026, Russia
| | - Takao Oishi
- Primate Research Institute, Kyoto University, Inuyama, Aichi 4848506, Japan
| | - Toshifumi Udono
- Kumamoto Sanctuary, Wildlife Research Center, Kyoto University, Uki, Kumamoto 8693201, Japan
| | - Katsushi Yamaguchi
- NIBB Core Research Facilities, National Institute for Basic Biology, Okazaki, Aichi 4448585, Japan
| | - Shuji Shigenobu
- NIBB Core Research Facilities, National Institute for Basic Biology, Okazaki, Aichi 4448585, Japan.,School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 4448585, Japan
| | - Akiyoshi Kakita
- Brain Research Institute, Niigata University, Niigata 9518585, Japan
| | - Hiroyuki Nawa
- Brain Research Institute, Niigata University, Niigata 9518585, Japan
| | - Philipp Khaitovich
- Skolkovo Institute of Science and Technology, Moscow 143026, Russia.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China.,Comparative Biology Laboratory, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 200031, China
| | - Yasuhiro Go
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi 4448585, Japan.,School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 4448585, Japan.,Department of Physiological Sciences, National Institute for Physiological Sciences, Okazaki, Aichi 4448585, Japan
| |
Collapse
|
10
|
Perez EJ, Tapanes SA, Loris ZB, Balu DT, Sick TJ, Coyle JT, Liebl DJ. Enhanced astrocytic d-serine underlies synaptic damage after traumatic brain injury. J Clin Invest 2017; 127:3114-3125. [PMID: 28714867 DOI: 10.1172/jci92300] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 05/26/2017] [Indexed: 01/09/2023] Open
Abstract
After traumatic brain injury (TBI), glial cells have both beneficial and deleterious roles in injury progression and recovery. However, few studies have examined the influence of reactive astrocytes in the tripartite synapse following TBI. Here, we have demonstrated that hippocampal synaptic damage caused by controlled cortical impact (CCI) injury in mice results in a switch from neuronal to astrocytic d-serine release. Under nonpathological conditions, d-serine functions as a neurotransmitter and coagonist for NMDA receptors and is involved in mediating synaptic plasticity. The phasic release of neuronal d-serine is important in maintaining synaptic function, and deficiencies lead to reductions in synaptic function and plasticity. Following CCI injury, hippocampal neurons downregulated d-serine levels, while astrocytes enhanced production and release of d-serine. We further determined that this switch in the cellular source of d-serine, together with the release of basal levels of glutamate, contributes to synaptic damage and dysfunction. Astrocyte-specific elimination of the astrocytic d-serine-synthesizing enzyme serine racemase after CCI injury improved synaptic plasticity, brain oscillations, and learning behavior. We conclude that the enhanced tonic release of d-serine from astrocytes after TBI underlies much of the synaptic damage associated with brain injury.
Collapse
Affiliation(s)
- Enmanuel J Perez
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Stephen A Tapanes
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Zachary B Loris
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Darrick T Balu
- Translational Psychiatry Laboratory, McLean Hospital, Belmont, Massachusetts, USA
| | - Thomas J Sick
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Joseph T Coyle
- Laboratory of Psychiatric and Molecular Neuroscience, McLean Hospital, Belmont, Massachusetts, USA
| | - Daniel J Liebl
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| |
Collapse
|
11
|
Prada Jardim A, Liu J, Baber J, Michalak Z, Reeves C, Ellis M, Novy J, de Tisi J, McEvoy A, Miserocchi A, Targas Yacubian EM, Sisodiya S, Thompson P, Thom M. Characterising subtypes of hippocampal sclerosis and reorganization: correlation with pre and postoperative memory deficit. Brain Pathol 2017; 28:143-154. [PMID: 28380661 PMCID: PMC5893935 DOI: 10.1111/bpa.12514] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 03/28/2017] [Indexed: 01/16/2023] Open
Abstract
Neuropathological subtypes of hippocampal sclerosis (HS) in temporal lobe epilepsy (The 2013 International League Against Epilepsy classification) are based on the qualitative assessment of patterns of neuronal loss with NeuN. In practice, some cases appear indeterminate between type 1 (CA1 and CA4 loss) and type 2 HS (CA1 loss) and we predicted that MAP2 would enable a more stringent classification. HS subtypes, as well as the accompanying alteration of axonal networks, regenerative capacity and neurodegeneration have been previously correlated with outcome and memory deficits and may provide prognostic clinical information. We selected 92 cases: 52 type 1 HS, 15 type 2 HS, 18 indeterminate‐HS and 7 no‐HS. Quantitative analysis was carried out on NeuN and MAP2 stained sections and a labeling index (LI) calculated for six hippocampal subfields. We also evaluated hippocampal regenerative activity (MCM2, nestin, olig2, calbindin), degeneration (AT8/phosphorylated tau) and mossy‐fiber pathway re‐organization (ZnT3). Pathology measures were correlated with clinical epilepsy history, memory and naming test scores and postoperative outcomes, at 1 year following surgery. MAP2 LI in indeterminate‐HS was statistically similar to type 2 HS but this clustering was not shown with NeuN. Moderate verbal and visual memory deficits were noted in all HS types, including 54% and 69% of type 2 HS. Memory deficits correlated with several pathology factors including lower NeuN or MAP2 LI in CA4, CA1, dentate gyrus (DG) and subiculum and poor preservation of the mossy fiber pathway. Decline in memory at 1 year associated with AT8 labeling in the subiculum and DG but not HS type. We conclude that MAP2 is a helpful addition in the classification of HS in some cases. Classification of HS subtype, however, did not significantly correlate with outcome or pre‐ or postoperative memory dysfunction, which was associated with multiple pathology factors including hippocampal axonal pathways, regenerative capacity and degenerative changes.
Collapse
Affiliation(s)
- Anaclara Prada Jardim
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Department of Neurology and Neurosurgery, Universidade Federal de Sao Paulo, UNIFESP, Sao Paulo, Brazil
| | - Joan Liu
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Jack Baber
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK
| | - Zuzanna Michalak
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Cheryl Reeves
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Matthew Ellis
- Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Jan Novy
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK.,Service de Neurologie, Département des Neurosciences Cliniques, CHUV, University of Lausanne, Switzerland
| | - Jane de Tisi
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK
| | - Andrew McEvoy
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Anna Miserocchi
- Departments of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | | | - Sanjay Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK.,Epilepsy Society, Epilepsy Society Research Centre, Buckinghamshire, SL9 0RJ, UK
| | - Pamela Thompson
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropsychology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK.,Epilepsy Society, Epilepsy Society Research Centre, Buckinghamshire, SL9 0RJ, UK
| | - Maria Thom
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| |
Collapse
|
12
|
Walrave L, Vinken M, Albertini G, De Bundel D, Leybaert L, Smolders IJ. Inhibition of Connexin43 Hemichannels Impairs Spatial Short-Term Memory without Affecting Spatial Working Memory. Front Cell Neurosci 2016; 10:288. [PMID: 28066184 PMCID: PMC5168429 DOI: 10.3389/fncel.2016.00288] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 12/02/2016] [Indexed: 12/15/2022] Open
Abstract
Astrocytes are active players in higher brain function as they can release gliotransmitters, which are essential for synaptic plasticity. Various mechanisms have been proposed for gliotransmission, including vesicular mechanisms as well as non-vesicular ones, for example by passive diffusion via connexin hemichannels (HCs). We here investigated whether interfering with connexin43 (Cx43) HCs influenced hippocampal spatial memory. We made use of the peptide Gap19 that blocks HCs but not gap junction channels and is specific for Cx43. To this end, we microinfused transactivator of transcription linked Gap19 (TAT-Gap19) into the brain ventricle of male NMRI mice and assessed spatial memory in a Y maze. We found that the in vivo blockade of Cx43 HCs did not affect the locomotor activity or spatial working memory in a spontaneous alternation Y maze task. Cx43 blockade did however significantly impair the spatial short-term memory in a delayed spontaneous alternation Y maze task. These results indicate that Cx43 HCs play a role in spatial short-term memory.
Collapse
Affiliation(s)
- Laura Walrave
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Center for Neurosciences, Vrije Universiteit Brussel Brussels, Belgium
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel Brussels, Belgium
| | - Giulia Albertini
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Center for Neurosciences, Vrije Universiteit Brussel Brussels, Belgium
| | - Dimitri De Bundel
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Center for Neurosciences, Vrije Universiteit Brussel Brussels, Belgium
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Ghent University Ghent, Belgium
| | - Ilse J Smolders
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Center for Neurosciences, Vrije Universiteit Brussel Brussels, Belgium
| |
Collapse
|
13
|
Pearson-Leary J, Osborne DM, McNay EC. Role of Glia in Stress-Induced Enhancement and Impairment of Memory. Front Integr Neurosci 2016; 9:63. [PMID: 26793072 PMCID: PMC4707238 DOI: 10.3389/fnint.2015.00063] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/05/2015] [Indexed: 12/20/2022] Open
Abstract
Both acute and chronic stress profoundly affect hippocampally-dependent learning and memory: moderate stress generally enhances, while chronic or extreme stress can impair, neural and cognitive processes. Within the brain, stress elevates both norepinephrine and glucocorticoids, and both affect several genomic and signaling cascades responsible for modulating memory strength. Memories formed at times of stress can be extremely strong, yet stress can also impair memory to the point of amnesia. Often overlooked in consideration of the impact of stress on cognitive processes, and specifically memory, is the important contribution of glia as a target for stress-induced changes. Astrocytes, microglia, and oligodendrocytes all have unique contributions to learning and memory. Furthermore, these three types of glia express receptors for both norepinephrine and glucocorticoids and are hence immediate targets of stress hormone actions. It is becoming increasingly clear that inflammatory cytokines and immunomodulatory molecules released by glia during stress may promote many of the behavioral effects of acute and chronic stress. In this review, the role of traditional genomic and rapid hormonal mechanisms working in concert with glia to affect stress-induced learning and memory will be emphasized.
Collapse
Affiliation(s)
- Jiah Pearson-Leary
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia Philadelphia, PA, USA
| | | | - Ewan C McNay
- Behavioral Neuroscience and Biology, University at Albany Albany, NY, USA
| |
Collapse
|