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Merino‐Serrais P, Plaza‐Alonso S, Hellal F, Valero‐Freitag S, Kastanauskaite A, Plesnila N, DeFelipe J. Structural changes of CA1 pyramidal neurons after stroke in the contralesional hippocampus. Brain Pathol 2024; 34:e13222. [PMID: 38012061 PMCID: PMC11007010 DOI: 10.1111/bpa.13222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/30/2023] [Indexed: 11/29/2023] Open
Abstract
Significant progress has been made with regard to understanding how the adult brain responds after a stroke. However, a large number of patients continue to suffer lifelong disabilities without adequate treatment. In the present study, we have analyzed possible microanatomical alterations in the contralesional hippocampus from the ischemic stroke mouse model tMCAo 12-14 weeks after transient middle cerebral artery occlusion. After individually injecting Lucifer yellow into pyramidal neurons from the CA1 field of the hippocampus, we performed a detailed three-dimensional analysis of the neuronal complexity, dendritic spine density, and morphology. We found that, in both apical (stratum radiatum) and basal (stratum oriens) arbors, CA1 pyramidal neurons in the contralesional hippocampus of tMCAo mice have a significantly higher neuronal complexity, as well as reduced spine density and alterations in spine volume and spine length. Our results show that when the ipsilateral hippocampus is dramatically damaged, the contralesional hippocampus exhibits several statistically significant selective alterations. However, these alterations are not as significant as expected, which may help to explain the recovery of hippocampal function after stroke. Further anatomical and physiological studies are necessary to better understand the modifications in the "intact" contralesional lesioned brain regions, which are probably fundamental to recover functions after stroke.
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Affiliation(s)
- Paula Merino‐Serrais
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología BiomédicaUniversidad Politécnica de MadridMadridSpain
- Departamento de Neurobiología Funcional y de SistemasInstituto Cajal, CSICMadridSpain
| | - Sergio Plaza‐Alonso
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología BiomédicaUniversidad Politécnica de MadridMadridSpain
- Departamento de Neurobiología Funcional y de SistemasInstituto Cajal, CSICMadridSpain
| | - Farida Hellal
- Laboratory of Experimental Stroke Research, Institute for Stroke and Dementia Research (ISD), University Hospital, Ludwig‐Maximilians‐University Munich (LMU)MunichGermany
- iTERM, Helmholtz CenterMunichGermany
- Munich Cluster of Systems Neurology (Synergy)MunichGermany
| | - Susana Valero‐Freitag
- Laboratory of Experimental Stroke Research, Institute for Stroke and Dementia Research (ISD), University Hospital, Ludwig‐Maximilians‐University Munich (LMU)MunichGermany
| | - Asta Kastanauskaite
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología BiomédicaUniversidad Politécnica de MadridMadridSpain
- Departamento de Neurobiología Funcional y de SistemasInstituto Cajal, CSICMadridSpain
| | - Nikolaus Plesnila
- Laboratory of Experimental Stroke Research, Institute for Stroke and Dementia Research (ISD), University Hospital, Ludwig‐Maximilians‐University Munich (LMU)MunichGermany
- Munich Cluster of Systems Neurology (Synergy)MunichGermany
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología BiomédicaUniversidad Politécnica de MadridMadridSpain
- Departamento de Neurobiología Funcional y de SistemasInstituto Cajal, CSICMadridSpain
- CIBER de Enfermedades Neurodegenerativas, Instituto de Salud Carlos IIIMadridSpain
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A realistic morpho-anatomical connection strategy for modelling full-scale point-neuron microcircuits. Sci Rep 2022; 12:13864. [PMID: 35974119 PMCID: PMC9381785 DOI: 10.1038/s41598-022-18024-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 08/03/2022] [Indexed: 01/03/2023] Open
Abstract
The modeling of extended microcircuits is emerging as an effective tool to simulate the neurophysiological correlates of brain activity and to investigate brain dysfunctions. However, for specific networks, a realistic modeling approach based on the combination of available physiological, morphological and anatomical data is still an open issue. One of the main problems in the generation of realistic networks lies in the strategy adopted to build network connectivity. Here we propose a method to implement a neuronal network at single cell resolution by using the geometrical probability volumes associated with pre- and postsynaptic neurites. This allows us to build a network with plausible connectivity properties without the explicit use of computationally intensive touch detection algorithms using full 3D neuron reconstructions. The method has been benchmarked for the mouse hippocampus CA1 area, and the results show that this approach is able to generate full-scale brain networks at single cell resolution that are in good agreement with experimental findings. This geometric reconstruction of axonal and dendritic occupancy, by effectively reflecting morphological and anatomical constraints, could be integrated into structured simulators generating entire circuits of different brain areas facilitating the simulation of different brain regions with realistic models.
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Merino-Serrais P, Plaza-Alonso S, Hellal F, Valero-Freitag S, Kastanauskaite A, Muñoz A, Plesnila N, DeFelipe J. Microanatomical study of pyramidal neurons in the contralesional somatosensory cortex after experimental ischemic stroke. Cereb Cortex 2022; 33:1074-1089. [PMID: 35353195 PMCID: PMC9930620 DOI: 10.1093/cercor/bhac121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 11/13/2022] Open
Abstract
At present, many studies support the notion that after stroke, remote regions connected to the infarcted area are also affected and may contribute to functional outcome. In the present study, we have analyzed possible microanatomical alterations in pyramidal neurons from the contralesional hemisphere after induced stroke. We performed intracellular injections of Lucifer yellow in pyramidal neurons from layer III in the somatosensory cortex of the contralesional hemisphere in an ischemic stroke mouse model. A detailed 3-dimensional analysis of the neuronal complexity and morphological alterations of dendritic spines was then performed. Our results demonstrate that pyramidal neurons from layer III in the somatosensory cortex of the contralesional hemisphere show selective changes in their dendritic arbors, namely, less dendritic complexity of the apical dendritic arbor-but no changes in the basal dendritic arbor. In addition, we found differences in spine morphology in both apical and basal dendrites comparing the contralesional hemisphere with the lesional hemisphere. Our results show that pyramidal neurons of remote areas connected to the infarct zone exhibit a series of selective changes in neuronal complexity and morphological distribution of dendritic spines, supporting the hypothesis that remote regions connected to the peri-infarcted area are also affected after stroke.
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Affiliation(s)
- Paula Merino-Serrais
- Corresponding author: Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Campus Montegancedo S/N, Pozuelo de Alarcón, Madrid 28223/Instituto Cajal (CSIC), Avenida Doctor Arce, 37, Madrid 28002, Spain.
| | - Sergio Plaza-Alonso
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28223, Spain,Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal, CSIC, Madrid 28002, Spain
| | - Farida Hellal
- Institute for Stroke and Dementia Research (ISD), University of Munich, Munich 81337, Germany,iTERM, Helmholtz center, Munich 85764, Germany
| | - Susana Valero-Freitag
- Institute for Stroke and Dementia Research (ISD), University of Munich, Munich 81337, Germany
| | - Asta Kastanauskaite
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28223, Spain,Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal, CSIC, Madrid 28002, Spain
| | - Alberto Muñoz
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28223, Spain,Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal, CSIC, Madrid 28002, Spain,Departamento de Biología Celular, Universidad Complutense, Madrid 28040, Spain
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research (ISD), University of Munich, Munich 81337, Germany,Munich Cluster of Systems Neurology (Synergy), Munich 85764, Germany
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28223, Spain,Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal, CSIC, Madrid 28002, Spain,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas. (CIBERNED), ISCIII, Madrid 28031, Spain
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