1
|
Surala M, Soso-Zdravkovic L, Munro D, Rifat A, Ouk K, Vida I, Priller J, Madry C. Lifelong absence of microglia alters hippocampal glutamatergic networks but not synapse and spine density. EMBO Rep 2024:10.1038/s44319-024-00130-9. [PMID: 38589666 DOI: 10.1038/s44319-024-00130-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/13/2024] [Accepted: 03/20/2024] [Indexed: 04/10/2024] Open
Abstract
Microglia sculpt developing neural circuits by eliminating excess synapses in a process called synaptic pruning, by removing apoptotic neurons, and by promoting neuronal survival. To elucidate the role of microglia during embryonic and postnatal brain development, we used a mouse model deficient in microglia throughout life by deletion of the fms-intronic regulatory element (FIRE) in the Csf1r locus. Surprisingly, young adult Csf1rΔFIRE/ΔFIRE mice display no changes in excitatory and inhibitory synapse number and spine density of CA1 hippocampal neurons compared with Csf1r+/+ littermates. However, CA1 neurons are less excitable, receive less CA3 excitatory input and show altered synaptic properties, but this does not affect novel object recognition. Cytokine profiling indicates an anti-inflammatory state along with increases in ApoE levels and reactive astrocytes containing synaptic markers in Csf1rΔFIRE/ΔFIRE mice. Notably, these changes in Csf1rΔFIRE/ΔFIRE mice closely resemble the effects of acute microglial depletion in adult mice after normal development. Our findings suggest that microglia are not mandatory for synaptic pruning, and that in their absence pruning can be achieved by other mechanisms.
Collapse
Affiliation(s)
- Michael Surala
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Neurophysiology, Charitéplatz 1, 10117, Berlin, Germany
| | - Luna Soso-Zdravkovic
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Neurophysiology, Charitéplatz 1, 10117, Berlin, Germany
| | - David Munro
- University of Edinburgh and UK Dementia Research Institute, Edinburgh, EH16 4TJ, UK
| | - Ali Rifat
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Neurophysiology, Charitéplatz 1, 10117, Berlin, Germany
- Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Koliane Ouk
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Neuropsychiatry and Laboratory of Molecular Psychiatry, Charitéplatz 1, 10117, Berlin, Germany
| | - Imre Vida
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute for Integrative Neuroanatomy, Charitéplatz 1, 10117, Berlin, Germany
| | - Josef Priller
- University of Edinburgh and UK Dementia Research Institute, Edinburgh, EH16 4TJ, UK.
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Neuropsychiatry and Laboratory of Molecular Psychiatry, Charitéplatz 1, 10117, Berlin, Germany.
- DZNE Berlin, 10117, Berlin, Germany.
- Department of Psychiatry and Psychotherapy; School of Medicine and Health, Technical University of Munich and German Center for Mental Health (DZPG), 81675, Munich, Germany.
| | - Christian Madry
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Neurophysiology, Charitéplatz 1, 10117, Berlin, Germany.
| |
Collapse
|