Ng a Zeiss light microscope (Axioskop, Oberkochen, Germany) interfaced with a

Ng a Zeiss light microscope (Axioskop, Oberkochen, Germany) interfaced with a CCD video camera (Kodak Megaplus, Rochester, NY, USA). Images of stained retinas were obtained at X40 magnification. The width of each retinal layer was quantified and analyzed using the Image-Pro Plus System for image analysis (v. 5.1, Media Cybernetics). 8?0 retinas of apoE3 and apoE4 retinas (three sections of each retina per slide) were stained and analyzed together. Each such staining was performed on retinas from two different sets of mice.Immunofluorescence and Confocal MicroscopyRetinal slices were washed X3 in PBS, after which they were blocked using PBS with 0.2 Tween and 0.2 Gelatine (PBSTG) for 2 hrs and washed with PBS. The slides were then incubated with the indicated primary antibody overnight at 4uC, after which they were washed (X3 with PBS-TG followed by X3 with PBS), incubated with secondary antibody for 2 hr at room temperature, and washed again (X3 with PBS-TG followed by X3 with PBS). The immunostained sections were then covered with coverslips utilizing Fluoroshield Mounting Medium that contained the nuclear stain DAPI (Abcam). The sections were immunostained with the following primary antibodies: Photoreceptors – rabbit anti-recoverin 1:1000 (Chemicon); Epigenetics Epigenetic Reader Domain Amacrine cells – rabbit anti-Pax6 1:400 (Covance), Bipolar cells – 16985061 sheep anti-CHX10 1:1000 (Xalpha), Rod bipolar cells – rabbit anti-PKCa 1:1200 (Santa cruz); Horizontal cells – rabbit antiCalbindin 1:1000 (Chemicon), Synapses – mouse anti-Synaptophysin 1:250 (Sigma); Guinea pig anti-VGluT1 1:2000 (Millipore) mouse anti-VGaT 1:250 (Synaptic systems) and rabbit antiVAChT 1:200 (Synaptic systems), which are markers for glutamatergic, GABAergic and cholinergic nerve terminals, respectively, Goat anti-human apoE 1:5000 (Calbiochem) and mouse anti-Glutamine Synthetase (GS) 1:300 (Millipore) which is a marker for Muller cells. The sections were visualized using a Confocal scanning laser microscope (Zeiss, LSM 510). Images (102461024 pixels at X25 or X40 magnification) were obtained by averaging 4 scans per slice. The intensities of immunofluorescence staining, expressed as the percentage of the area stained above a fixed threshold background, were calculated utilizing the Image-Pro Plus System (version 5.1, Media Cybernetics) as previously described [34]. 8?10 retinas of apoE3 and apoE4 retinas (three sections of each retina per slide) were stained and analyzed together. Each such staining was performed on retinas from two different sets of mice. All the images for each immunostaining were obtained under identical conditions, and their quantitative analyses were performed with no further handling.Materials and Methods Ethics StatementThe experiments were approved by the Tel-Aviv University Animal Care Committee (Permit # L-11-041). Every effort was made to reduce animal stress and to minimize animal usage.Transgenic MiceApoE-targeted replacement mice, in which the endogenous mouse apoE was replaced by either human apoE3 or apoE4, were created by gene targeting, as described in [31]. The mice used were purchased from Taconic (Germantown, NY). Mice were back-crossed to C57BL/6J (Harlan 2BL/610) for ten generations and were homozygous for the apoE3 (3/3) or apoE4 (4/4) alleles; hereafter, these mice are referred to as apoE3 and apoE4 mice, respectively. The apoE genotype of the mice was confirmed by PCR analysis, as described previously [32,33]. All the experiments were performed on age-matched.Ng a Zeiss light microscope (Axioskop, Oberkochen, Germany) interfaced with a CCD video camera (Kodak Megaplus, Rochester, NY, USA). Images of stained retinas were obtained at X40 magnification. The width of each retinal layer was quantified and analyzed using the Image-Pro Plus System for image analysis (v. 5.1, Media Cybernetics). 8?0 retinas of apoE3 and apoE4 retinas (three sections of each retina per slide) were stained and analyzed together. Each such staining was performed on retinas from two different sets of mice.Immunofluorescence and Confocal MicroscopyRetinal slices were washed X3 in PBS, after which they were blocked using PBS with 0.2 Tween and 0.2 Gelatine (PBSTG) for 2 hrs and washed with PBS. The slides were then incubated with the indicated primary antibody overnight at 4uC, after which they were washed (X3 with PBS-TG followed by X3 with PBS), incubated with secondary antibody for 2 hr at room temperature, and washed again (X3 with PBS-TG followed by X3 with PBS). The immunostained sections were then covered with coverslips utilizing Fluoroshield Mounting Medium that contained the nuclear stain DAPI (Abcam). The sections were immunostained with the following primary antibodies: Photoreceptors – rabbit anti-recoverin 1:1000 (Chemicon); Amacrine cells – rabbit anti-Pax6 1:400 (Covance), Bipolar cells – 16985061 sheep anti-CHX10 1:1000 (Xalpha), Rod bipolar cells – rabbit anti-PKCa 1:1200 (Santa cruz); Horizontal cells – rabbit antiCalbindin 1:1000 (Chemicon), Synapses – mouse anti-Synaptophysin 1:250 (Sigma); Guinea pig anti-VGluT1 1:2000 (Millipore) mouse anti-VGaT 1:250 (Synaptic systems) and rabbit antiVAChT 1:200 (Synaptic systems), which are markers for glutamatergic, GABAergic and cholinergic nerve terminals, respectively, Goat anti-human apoE 1:5000 (Calbiochem) and mouse anti-Glutamine Synthetase (GS) 1:300 (Millipore) which is a marker for Muller cells. The sections were visualized using a Confocal scanning laser microscope (Zeiss, LSM 510). Images (102461024 pixels at X25 or X40 magnification) were obtained by averaging 4 scans per slice. The intensities of immunofluorescence staining, expressed as the percentage of the area stained above a fixed threshold background, were calculated utilizing the Image-Pro Plus System (version 5.1, Media Cybernetics) as previously described [34]. 8?10 retinas of apoE3 and apoE4 retinas (three sections of each retina per slide) were stained and analyzed together. Each such staining was performed on retinas from two different sets of mice. All the images for each immunostaining were obtained under identical conditions, and their quantitative analyses were performed with no further handling.Materials and Methods Ethics StatementThe experiments were approved by the Tel-Aviv University Animal Care Committee (Permit # L-11-041). Every effort was made to reduce animal stress and to minimize animal usage.Transgenic MiceApoE-targeted replacement mice, in which the endogenous mouse apoE was replaced by either human apoE3 or apoE4, were created by gene targeting, as described in [31]. The mice used were purchased from Taconic (Germantown, NY). Mice were back-crossed to C57BL/6J (Harlan 2BL/610) for ten generations and were homozygous for the apoE3 (3/3) or apoE4 (4/4) alleles; hereafter, these mice are referred to as apoE3 and apoE4 mice, respectively. The apoE genotype of the mice was confirmed by PCR analysis, as described previously [32,33]. All the experiments were performed on age-matched.