Table 1.
Primary antibodies used for immunohistochemical analysis.
Figure 1.
The antibody CT20 detects APP-immunoreactive protein in WT but not APP-KO retina.
(A) Immunohistochemistry on a transverse retinal section from an adult WT mouse shows CT20 labels APP immunoreactivity in the outer plexiform layer (OPL), inner nuclear layer (INL), inner plexiform layer (IPL) and ganglion cell layer (GCL) but not in the outer nuclear layer (ONL). (B) The APP-KO retina does not label with the CT20 antibody, suggesting that the antibody is specific for APP in retinal sections. Scale, 20 microns.
Figure 2.
APP-immunoreactivity (IR) in the WT mouse retina colocalises with horizontal cells and cone bipolar cells but not rod bipolar cells.
Immunohistochemistry on a transverse retinal section from an adult WT mouse for (A) horizontal cells labelled with Calbindin, and (B) APP-IR, showing (C) colocalisation. Immunohistochemistry for (D) rod bipolar cells labelled with PKCα and (E) APP-IR, showing that the markers do not colocalise (F). Immunohistochemistry for (G) cone bipolar cells (Type 2 and 6) labelled with a ZNP-1 and (H) APP-IR, showing (I) colocalisation. Arrows indicate examples of colocalisation. Outer plexiform layer (OPL), inner nuclear layer (INL), inner plexiform layer (IPL) and ganglion cell layer (GCL). Scale, 50 microns.
Figure 3.
APP-immunoreactivity (IR) in the WT mouse retina colocalises with with calretinin positive- and GABA positive-amacrine cells, as well as ganglion cells.
Immunohistochemistry on a transverse retinal section from an adult WT mouse for (A) amacrine cells labelled with Calretinin, and (B) APP-IR, showing (C) colocalisation. Immunohistochemistry for (D) GABAergic amacrine labelled with an antibody against GABA and (E) APP-IR, showing (F) colocalisation. Immunohistochemistry for (G) ganglion cells labelled with an antibody against GFP to localise YFP positive cells in the thy1-HYFP mouse and (H) APP-IR, showing (I) colocalisation. Arrows indicate examples of colocalisation, while * indicates a calretinin positive cell not labelled for APP-IR. Inner nuclear layer (INL), inner plexiform layer (IPL) and ganglion cell layer (GCL). Scale, 50 microns.
Figure 4.
The function of the rod pathway is altered in the adult APP-KO mouse.
(A) Representative waveforms of the rod ERG recorded from dark adapted, 3 month old WT (black) and APP-KO (grey) mice in response to a 2.1 log cd.s/m2 intensity flash. The photoreceptor derived, rod PIII was not altered in either (B) amplitude or (C) sensitivity in the APP-KO mouse when compared with the WT response. The post-photoreceptor response, the rod PII (D) was significantly smaller in amplitude in the APP-KO mouse. (E) Representative waveforms of the oscillatory potentials (OPs) extracted from rod ERG in WT (n = 16) and APP-KO (n = 14) mice. (F) All of the inner retinal derived OPs measured were significantly enhanced in the APP-KO mouse. Results expressed as mean +/− SEM, *, p<0.05, **, p<0.01; ***, p<0.001.
Figure 5.
The function of the cone pathway is altered in the APP-KO mouse.
(A) Representative waveforms of the cone ERG recorded from 3 month old WT (black) and APP-KO (grey) mice in response to the second flash of a twin flash paradigm ERG (2.1 log cd.s/m2 flash intensity). (B) The cone pathway post-photoreceptor response, the cone PII was found to be smaller in amplitude in APP-KO mice when compared with the WT response. (C) The photopic visual acuity, assessed using the optokinetic reflex to determine the spatial frequency threshold, was physiologically similar between APP-KO and WT mice with age. Results expressed as mean +/− SEM. **, p<0.01.
Figure 6.
The number and morphology of inner retinal neurons is similar in adult WT and APP-KO mice.
Immunohistochemistry using various cell markers was used to probe for gross changes in retinal cell classes in the APP-KO mice. Similar cell profiles were observed for: horizontal cells labelled with Calbindin in (A) WT and (B) APP-KO; rod bipolar cells labelled with PKCα in (C) WT and (D) APP-KO mice; cone bipolar cells (type 2 and 6) labelled with ZNP-1 in (E) WT and (F) APP-KO mice; calretinin-positive amacrine cells in (G) WT and (H) APP-KO mice; GABAergic amacrine cells labelled for GABA in (I) WT and (J) APP-KO mice and; ganglion cells and GABAergic amacrine cells labelled with NueN in (K) WT and (L) APP-KO mice. Outer nuclear layer (ONL), outer plexiform layer (OPL), inner nuclear layer (INL), inner plexiform layer (IPL) and ganglion cell layer (GCL). Scale, 50 microns.