Impaired Functional Connectivity Underlies Fragile X Syndrome
Fragile X syndrome (FXS), the most common form of inherited intellectual disability, is caused by a developmentally regulated silencing of the <i>FMR1</i> gene, but its effect on human neuronal network development and function is not fully understood. Here, we isolated isogenic human emb...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-02-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/23/4/2048 |
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| author | Lital Gildin Rossana Rauti Ofir Vardi Liron Kuznitsov-Yanovsky Ben M. Maoz Menahem Segal Dalit Ben-Yosef |
| author_facet | Lital Gildin Rossana Rauti Ofir Vardi Liron Kuznitsov-Yanovsky Ben M. Maoz Menahem Segal Dalit Ben-Yosef |
| author_sort | Lital Gildin |
| collection | DOAJ |
| description | Fragile X syndrome (FXS), the most common form of inherited intellectual disability, is caused by a developmentally regulated silencing of the <i>FMR1</i> gene, but its effect on human neuronal network development and function is not fully understood. Here, we isolated isogenic human embryonic stem cell (hESC) subclones—one with a full FX mutation and one that is free of the mutation (control) but shares the same genetic background—differentiated them into induced neurons (iNs) by forced expression of <i>NEUROG-1</i>, and compared the functional properties of the derived neuronal networks. High-throughput image analysis demonstrates that FX-iNs have significantly smaller cell bodies and reduced arborizations than the control. Both FX- and control-neurons can discharge repetitive action potentials, and FX neuronal networks are also able to generate spontaneous excitatory synaptic currents with slight differences from the control, demonstrating that iNs generate more mature neuronal networks than the previously used protocols. MEA analysis demonstrated that FX networks are hyperexcitable with significantly higher spontaneous burst-firing activity compared to the control. Most importantly, cross-correlation analysis enabled quantification of network connectivity to demonstrate that the FX neuronal networks are significantly less synchronous than the control, which can explain the origin of the development of intellectual dysfunction associated with FXS. |
| first_indexed | 2024-03-09T21:44:56Z |
| format | Article |
| id | doaj.art-5549077711264e5baf7bc5c2ce49e4de |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-09T21:44:56Z |
| publishDate | 2022-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-5549077711264e5baf7bc5c2ce49e4de2023-11-23T20:19:02ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672022-02-01234204810.3390/ijms23042048Impaired Functional Connectivity Underlies Fragile X SyndromeLital Gildin0Rossana Rauti1Ofir Vardi2Liron Kuznitsov-Yanovsky3Ben M. Maoz4Menahem Segal5Dalit Ben-Yosef6Wolfe PGD Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital Tel-Aviv Sourasky Medical Center, Tel-Aviv 64239, IsraelDepartment of Biomedical Engineering, Tel-Aviv University, Tel-Aviv 69978, IsraelDepartment of Biomedical Engineering, Tel-Aviv University, Tel-Aviv 69978, IsraelWolfe PGD Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital Tel-Aviv Sourasky Medical Center, Tel-Aviv 64239, IsraelDepartment of Biomedical Engineering, Tel-Aviv University, Tel-Aviv 69978, IsraelDepartment of Brain Sciences, The Weizmann Institute, Rehovot 76100, IsraelWolfe PGD Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital Tel-Aviv Sourasky Medical Center, Tel-Aviv 64239, IsraelFragile X syndrome (FXS), the most common form of inherited intellectual disability, is caused by a developmentally regulated silencing of the <i>FMR1</i> gene, but its effect on human neuronal network development and function is not fully understood. Here, we isolated isogenic human embryonic stem cell (hESC) subclones—one with a full FX mutation and one that is free of the mutation (control) but shares the same genetic background—differentiated them into induced neurons (iNs) by forced expression of <i>NEUROG-1</i>, and compared the functional properties of the derived neuronal networks. High-throughput image analysis demonstrates that FX-iNs have significantly smaller cell bodies and reduced arborizations than the control. Both FX- and control-neurons can discharge repetitive action potentials, and FX neuronal networks are also able to generate spontaneous excitatory synaptic currents with slight differences from the control, demonstrating that iNs generate more mature neuronal networks than the previously used protocols. MEA analysis demonstrated that FX networks are hyperexcitable with significantly higher spontaneous burst-firing activity compared to the control. Most importantly, cross-correlation analysis enabled quantification of network connectivity to demonstrate that the FX neuronal networks are significantly less synchronous than the control, which can explain the origin of the development of intellectual dysfunction associated with FXS.https://www.mdpi.com/1422-0067/23/4/2048Fragile X syndromedisease modelinghuman embryonic stem cellsneural differentiationMEAelectrophysiology |
| spellingShingle | Lital Gildin Rossana Rauti Ofir Vardi Liron Kuznitsov-Yanovsky Ben M. Maoz Menahem Segal Dalit Ben-Yosef Impaired Functional Connectivity Underlies Fragile X Syndrome International Journal of Molecular Sciences Fragile X syndrome disease modeling human embryonic stem cells neural differentiation MEA electrophysiology |
| title | Impaired Functional Connectivity Underlies Fragile X Syndrome |
| title_full | Impaired Functional Connectivity Underlies Fragile X Syndrome |
| title_fullStr | Impaired Functional Connectivity Underlies Fragile X Syndrome |
| title_full_unstemmed | Impaired Functional Connectivity Underlies Fragile X Syndrome |
| title_short | Impaired Functional Connectivity Underlies Fragile X Syndrome |
| title_sort | impaired functional connectivity underlies fragile x syndrome |
| topic | Fragile X syndrome disease modeling human embryonic stem cells neural differentiation MEA electrophysiology |
| url | https://www.mdpi.com/1422-0067/23/4/2048 |
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