The classical complement cascade mediates CNS synapse elimination.
Document Type
Article
Publication Date
2007
Keywords
Animals-Newborn, Astrocytes, Central-Nervous-System, Complement-Activation, Complement-C1q, Complement-C3, Geniculate-Bodies, Glaucoma, Long-Term-Synaptic-Depression, Mice, Mice-Inbred-DBA, Mice-Knockout, RNA-Messenger, Retina, Retinal-Ganglion-Cells, Synapses, Up-Regulation
First Page
1164
Last Page
1178
JAX Source
Cell 2007 Dec; 131(6):1164-78.
Abstract
During development, the formation of mature neural circuits requires the selective elimination of inappropriate synaptic connections. Here we show that C1q, the initiating protein in the classical complement cascade, is expressed by postnatal neurons in response to immature astrocytes and is localized to synapses throughout the postnatal CNS and retina. Mice deficient in complement protein C1q or the downstream complement protein C3 exhibit large sustained defects in CNS synapse elimination, as shown by the failure of anatomical refinement of retinogeniculate connections and the retention of excess retinal innervation by lateral geniculate neurons. Neuronal C1q is normally downregulated in the adult CNS; however, in a mouse model of glaucoma, C1q becomes upregulated and synaptically relocalized in the adult retina early in the disease. These findings support a model in which unwanted synapses are tagged by complement for elimination and suggest that complement-mediated synapse elimination may become aberrantly reactivated in neurodegenerative disease.
Recommended Citation
Stevens B,
Allen NJ,
Vazquez LE,
Howell GR,
Christopherson KS,
Nouri N,
Micheva KD,
Mehalow AK,
Huberman AD,
Stafford B,
Sher A,
Litke AM,
Lambris JD,
Smith SJ,
John SW,
Barres BA.
The classical complement cascade mediates CNS synapse elimination. Cell 2007 Dec; 131(6):1164-78.