We describe here the identification and molecular characterization of a new brain protein that we named SV2C because it is homologous to the synaptic vesicle proteins SV2A and SV2B, and because it is also recognized by the monoclonal SV2 antibody that led to the initial discovery of SV2A and SV2B.

SV2A PET measures are correlated with functional connectivity across brain networks, and a number of other measures of brain function, including glucose metabolism.

SV2A, one of three isoforms of SV2, is ubiquitously expressed throughout the brain and is present in GABAergic and glutamatergic presynaptic nerve terminals 66.

In intact postmortem tissue, SV2C localizes to terminals and somata in mouse, macaque, and human brain. In accordance with previous reports, we found that in mice, SV2C is expressed primarily in the basal ganglia and colocalizes with markers of dopaminergic, GABAergic, and cholinergic neurons.

The immunofluorescence staining of SV2 was enhanced by the catalyzed reporter deposition (CARD) method with biotinyl tyramide 21,22 as described below. For double-immunofluorescence staining, the sections were incubated with a cocktail of two antibodies: SV2 (anti-mouse) plus polyclonal antibody overnight at room temperature → biotinylated ...