Fig. 3.

Extensive labeling of C1q within dendritic shafts in postsynaptic compartments in aged monkey dlPFC layer III. a–d C1q immunolabeling is found accumulating in the dendritic shafts, and the label is often associated with abnormal mitochondria-on-a-string (MOAS) profiles in aged monkey dlPFC layer III. a The immunolabeling shows association with synapses and postsynaptic density and associated with MOAS-like profile. b The immunolabeling is associated with the inner aspect of the shaft plasmalemma, and the label appears subjacent to the plasma membrane. c, d C1q labeling is visualized in association with microtubules in the intracellular space, in close proximity to MOAS-like profiles. Synapses are between arrows and arrowheads (symmetric synapses). Color-coded arrowheads (purple) point to C1q immunoreactivity. Profiles are pseudocolored for clarity. Ax, axon; Den, dendrite; Mit, mitochondria; G, glia. Scale bars, 200 nm