Accumulation of murine subretinal macrophages: effects of age, pigmentation and CX3CR1

Neurobiol Aging. 2012 Aug;33(8):1769-76. doi: 10.1016/j.neurobiolaging.2011.03.010. Epub 2011 May 13.


Macrophages or activated microglia in the subretinal space are considered a hallmark of some retinal pathologies. We investigated the effects of age, pigmentation and CX(3)CR1 deficiency on the accumulation of macrophages/activated microglia in the outer retina of young and old Cx(3)cr1(gfp/gfp) (CX(3)CR1-deficient) or Cx(3)cr1(gfp/+) mice on either a pigmented (C57BL/6) or albino (BALB/c) background. Quantitative analysis of immunostained retinal-choroidal whole mounts revealed an increase in subretinal macrophage (SRMΦ) numbers in young Cx(3)cr1(gfp/gfp) mice compared with Cx(3)cr1(gfp/+) mice, however the increase was more marked in albino Cx(3)cr1(gfp/gfp) mice. In aged mice, large numbers of SRMΦ/activated microglia replete with autofluorescent debris were noted in both old pigmented Cx(3)cr1(gfp/gfp) and Cx(3)cr1(gfp/+) mice proving this accumulation was not CX(3)CR1-dependent. While CX(3)CR1 deficiency leads to an early onset of SRMΦ accumulation, our data reveal that this change occurs in both aged Cx(3)cr1(gfp/+) and Cx(3)cr1(gfp/gfp) pigmented mice in the absence of marked retinal degeneration and is likely a normal response to aging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / metabolism*
  • Aging / pathology*
  • Animals
  • CX3C Chemokine Receptor 1
  • Female
  • Macrophages / cytology*
  • Macrophages / metabolism*
  • Male
  • Mice
  • Mice, Knockout
  • Microglia
  • Receptors, Chemokine / genetics
  • Receptors, Chemokine / metabolism*
  • Retina / cytology
  • Retina / metabolism*
  • Retinal Pigments / metabolism*


  • CX3C Chemokine Receptor 1
  • Cx3cr1 protein, mouse
  • Receptors, Chemokine
  • Retinal Pigments