The impact of oral escitalopram treatment on the function of retinal interneurons in the rat model of retinal ischemia – a pilot study

Abstract

AbstractPurposeTo evaluate the impact of oral treatment with SSRI – escitalopram (EC) on the function of interneurons (IN) assessed in electroretinography.MethodsSix Long Evans rats were treated orally with SSRI‐escitalopram (n=3) or phosphate buffered saline‐PBS (n=3) for 6 weeks daily. After 4 weeks transient elevation of intraocular pressure (IOP) was inducted in the right eye of every rat in order to induce retinal ischemia (IC). Electroretinography (ERG) was performed using Celeris device and oscillatory potentials were analysed (OPs) in 4 time points ‐ before drug administration, before IC induction and 7 & 14 days after it. After 6 weeks rats were sacrificed, retinas were isolated in order to conduct the histological assessment and cell counts. Western Blot analysis was performed in order to assess BDNF and connexin 36 content in retinas and brains.ResultsThe mean peak IOP was 24 mmHg in the right eye and 12 mmHg in the left eye and was similar in treated and control groups. In both groups no loss of RGC density was noted between the eye with induced IC and the healthy one (80 ± 31 vs 76 ± 20 cells/visual field for EC and 55 ± 10 vs 55 ± 11 for PBS; p > 0.05). In the functional measurements in the EC group amplitudes of all scotopic OPs (OP1‐5) were significantly higher 14 days after IC induction when compared to control group (p < 0.05), where deep disturbance of IN function was observed, specifically for OP2‐4, expressed in significant reduction of OP amplitudes (p < 0.05). Similar changes were not observed in photopic conditions.ConclusionsOral treatment with EC prevents desynchronization of retinal IN function during ischemic conditions in a rat. Observations presented above may become crucial for new therapeutic methods for vascular pathologies of the retina.