C1q and immunoglobulins mediate activity-dependent synapse loss in the adult brain

G Gerard Crowley M Minjung Kim (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) N Nathanael O’Neill (Research Department of Epilepsy, Queen Square Institute of Neurology, University College London, London, UK.) E Emir Turkes (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) F Fateme Ghasemi (A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.) L Luca Giudice (A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.) S Sebastiaan De Schepper B Benjy J. Y. Tan (Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, UK.) B Benito Maffei (Research Department of Epilepsy, Queen Square Institute of Neurology, University College London, London, UK.) L Laís S. S. Ferreira (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) J Julie Rebejac (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) J Javier Rueda-Carrasco M Margarita Toneva (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) J John Christian Fajardo (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) J Judy Z. Ge (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) Z Zhengyue Grace Yang (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) P Paula Korhonen (A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.) P Phillip Muckett (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) D Damaris Bennett (The Francis Crick Institute, London, UK.) C Camille Paoletti (UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.) T Tammie T. M. Sow (Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, UK.) D David A. Posner (Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, UK.) A Annerieke Sierksma D Dimitra Sokolova V Viktoras Konstantellos L Leen Ali (Brain and Systems Immunology Laboratory, Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium.) K Kiavash Movahedi A Andrew F. MacAskill (Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.) V Victor L. J. Tybulewicz (The Francis Crick Institute, London, UK.) T Tarja Malm (A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.) G Gabriele Lignani (Research Department of Epilepsy, Queen Square Institute of Neurology, University College London, London, UK.) M Menna R. Clatworthy S Soyon Hong

Abstract

Complement component 1q (C1q), the initiator of the classical complement cascade, mediates synaptic elimination in development and disease, yet the triggers for its deposition on synapses remain unclear. Using in vivo chemogenetics, we demonstrate that neuronal hyperactivity induces region-specific, C1q-dependent synapse loss in the adult hippocampus. Suppressing perforant pathway hyperactivity in a mouse model of Alzheimer’s disease reduced local amyloid-β amounts and C1q deposition and partially rescued synapse loss. Combining spatial transcriptomics, live cell tracking, and super-resolution microscopy, we identified association of antibody-secreting B-lineage cells in the adult hippocampus with activity-dependent, C1q-mediated synapse loss under physiological conditions. Together, these findings link neuronal hyperactivity to C1q-mediated synapse loss in the adult brain and implicate immunoglobulins as players in this process.

Article Details

Journal Science
Volume / Issue Vol. 393, Issue 6807
Published July 09, 2026
ISSN 0036-8075
Publisher American Association for the Advancement of Science

Journal Info

Science

American Association for the Advancement of Science

ISSN: 0036-8075 Social Sciences

Authors (33)

G

Gerard Crowley

M

Minjung Kim

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

N

Nathanael O’Neill

Research Department of Epilepsy, Queen Square Institute of Neurology, University College London, London, UK.

E

Emir Turkes

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

F

Fateme Ghasemi

A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.

L

Luca Giudice

A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.

S

Sebastiaan De Schepper

B

Benjy J. Y. Tan

Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, UK.

B

Benito Maffei

Research Department of Epilepsy, Queen Square Institute of Neurology, University College London, London, UK.

L

Laís S. S. Ferreira

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

J

Julie Rebejac

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

J

Javier Rueda-Carrasco

M

Margarita Toneva

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

J

John Christian Fajardo

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

J

Judy Z. Ge

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

Z

Zhengyue Grace Yang

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

P

Paula Korhonen

A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.

P

Phillip Muckett

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

D

Damaris Bennett

The Francis Crick Institute, London, UK.

C

Camille Paoletti

UK Dementia Research Institute, Institute of Neurology, University College London, London, UK.

T

Tammie T. M. Sow

Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, UK.

D

David A. Posner

Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, UK.

A

Annerieke Sierksma

D

Dimitra Sokolova

V

Viktoras Konstantellos

L

Leen Ali

Brain and Systems Immunology Laboratory, Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium.

K

Kiavash Movahedi

A

Andrew F. MacAskill

Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.

V

Victor L. J. Tybulewicz

The Francis Crick Institute, London, UK.

T

Tarja Malm

A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.

G

Gabriele Lignani

Research Department of Epilepsy, Queen Square Institute of Neurology, University College London, London, UK.

M

Menna R. Clatworthy

S

Soyon Hong