Specific accumulation
of LPNP-Au-555 in microglial cells in the
rat hypothalamus. (A1–A3) Colocalization of LPNP-Au-555 (red)
and ionized calcium-binding adaptor molecule 1 immunoreactivity (Iba1-ir,
green) in microglial cells. The dotted lines in panels (A1, A2) show
the diffusion of LPNP-Au-555 at a radius of ≈300 μm around
the injection spot (asterisk in panels A1, A2). An arrowhead in panel
(A1) shows an Iba1-ir microglial cell that does not contain LPNP-Au.
(A4) NeuroTrace histochemical staining (blue) in the same area of
panels (A1–A3). (B1–B4) High-magnification images of
the area framed in panels (A1, A2, A4). Arrows in panel (B1) show
Iba1-ir microglia containing LPNP-Au-555. Microglia located at the
edge of the area diffused by LPNP-Au-555 are indicated by arrowheads
in panel (B1). Panels (B3, B4) show no accumulation of LPNP-Au-555
in the NeuroTrace-stained neurons. (C1–C4) No accumulation
of LPNP-Au-555 is observed in glial fibrillary acidic protein-ir (GFAP-ir)
astrocytes (cyan). Arrows in panel (C1) show microglia containing
both LPNP-Au-555 and Iba1-ir. n = 4. Scale bar: 100
μm in panels (A1–A4) and 20 μm in panels (B1–B4)
and (C1–C4).