Skip to main content
. 2023 Jun 6;78(9):1523–1534. doi: 10.1093/gerona/glad134

Figure 3.

Figure 3.

Age-related alterations in complement cascade C1q signaling in dorsolateral prefrontal cortex Layer III. C1q expression accumulates in glia and postsynaptically in dendritic spines and dendritic shafts, with a sparser expression in axon terminals. Within dendritic spines, C1q aggregates in perisynaptic and extrasynaptic subcompartments in association with the spine apparatus of glutamatergic synapses. Within dendritic shafts, C1q aggregates in close proximity to dysmorphic mitochondria. We hypothesize that the rise in complement C1q signaling in the aged dlPFC may be due to age-related dysregulation of feedforward cAMP-PKA-calcium signaling but may also cause calcium overload of mitochondria and the initiation of inflammatory actions to eliminate dysfunctional neuronal elements and synapses by microglia-mediated phagocytosis (144).