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1. Amphetamine-induced c-fos and egr-1 expression in the striatum was used as a model in which to study the effects of antisense oligodeoxynucleotides (ODNs) directed at c-fos. Using direct infusions of ODNs into the striata of animals we have demonstrated that c-fos antisense ODNs retain most of their biological activity with 2- or 3-base substitutions. The c-fos antisense and mismatch ODNs attenuated Fos immunoreactivity but had little effect on Egr-1 immunoreactivity. 2. In another group of studies examining the role of c-fos in amygdala kindling, we have demonstrated that ODNs cause neurotoxic damage following repeated daily infusions into the amygdala. The damage observed was greatly diminished when the time interval between infusions was extended.

PURPOSE. We implemented optical coherence tomography angiography (OCT-A) in mice to: (1) develop quantitative parameters from OCT-A images, (2) measure the reproducibility of the parameters, and (3) determine the impact of experimental models of inner and outer retinal damage on OCT-A findings. METHODS. OCT-A images were acquired with a customized system (Spectralis Multiline OCT2). To assess reproducibility, imaging was performed five times over 1 month. Inner retinal damage was induced with optic nerve transection, crush, or intravitreal N-methyl-d-aspartic acid injection in transgenic mice with fluorescently labeled retinal ganglion cells (RGCs). Light-induced retinal damage was induced in albino mice. Mice were imaged at baseline and serially post injury. Perfusion density, vessel length, and branch points were computed from OCT-A images of the superficial, intermediate, and deep vascular plexuses. RESULTS. The range of relative differences measured between sessions across the vascular plexuses were: perfusion density (2.8%-7.0%), vessel length (1.9%-4.1%), and branch points (1.9%-5.0%). In mice with progressive RGC loss, imaged serially and culminating in around 70% loss in the fluorescence signal and 18% loss in inner retinal thickness, there were no measurable changes in any OCT-A parameter up to 4 months post injury that exceeded measurement variability. However, light-induced retinal damage elicited a progressive loss of the deep vascular plexus signal, starting as early as 3 days post injury. CONCLUSIONS. Vessel length and branch points were generally the most reproducible among the parameters. Injury causing RGC loss in mice did not elicit an early change in the OCT-A signal.

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Citation: Blandford SN, Hooper ML, Yabana T, Chauhan BC, Baldridge WH, Farrell SRM. Retinal characterization of the Thy1-GCaMP3 transgenic mouse line after optic nerve transection. Invest Ophthalmol Vis Sci. 2019;60:183-191. https://doi.org/ 10.1167/iovs.18-25861PURPOSE. GCaMP3 is a genetically encoded calcium indicator for monitoring intracellular calcium dynamics. We characterized the expression pattern and functional properties of GCaMP3 in the Thy1-GCaMP3 transgenic mouse retina. METHODS.To determine the specificity of GCaMP3 expression, Thy1-GCaMP3 (B6; CBA-Tg(Thy1-GCaMP3)6Gfng/J) retinas were processed for immunohistochemistry with anti-green fluorescent protein (anti-GFP, to enhance GCaMP3 fluorescence), anti-RBPMS (retinal ganglion cell [RGC]-specific marker), and antibodies against amacrine cell markers (ChAT, GABA, GAD67, syntaxin). Calcium imaging was used to characterize functional responses of GCaMP3-expressing (GCaMPþ) cells by recording calcium transients evoked by superfusion of kainic acid (KA; 10, 50, or 100 lM). In a subset of animals, optic nerve transection (ONT) was performed 3, 5, or 7 days prior to calcium imaging. RESULTS. GFP immunoreactivity colocalized with RBPMS but not amacrine cell markers in bothONT and non-ONT (control) groups. Calcium transients evoked by KA were reduced after ONT (50 lM KA; DF/F 0 [SD]; control: 1.00 [0.67], day 3: 0.50 [0.35], day 5: 0.31 [0.28], day 7: 0.35 [0.36]; P < 0.05 versus control). There was also a decrease in the number of GCaMP3þ cells after ONT (cells/mm 2 [SD]; control: 2198 [453], day 3: 2224 [643], day 5: 1383 [375], day 7: 913 [178]; P < 0.05). Furthermore, the proportion of GCaMP3þ cells that responded to KA decreased after ONT (50 lM KA, 97%, 54%, 47%, and 58%; control, 3, 5, and 7 days, respectively). CONCLUSIONS.Following ONT, functional RGC responses are lost prior to the loss of RGC somata, suggesting that anatomical markers of RGCs may underestimate the extent of RGC dysfunction.