Effects of Subretinal Electrical Stimulation in Mer-KO Mice

Mocko, Julie A.; Kim, Moon J.; Faulkner, Amanda E.; Cao, Yang; Ciavatta, Vincent T.; Pardue, Machelle T.

doi:10.1167/iovs.10-6750

Cited by 23 publications

(24 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[52][53][54] Responses were recorded to flash stimuli presented in order of increasing intensity using a signal averaging system (UTAS 3000; LKC Technologies, Gaithersburg, MD). ERG stimuli consisted of a 10-step dark-adapted series (À3.4 to 2.1 log cd s/m 2 ) to isolate rod-dominated 55 and rod/cone mixed responses.…”

Section: Erg Testing and Analysis In Ratsmentioning

confidence: 99%

Rodent Hyperglycemia-Induced Inner Retinal Deficits are Mirrored in Human Diabetes

Pardue

Barnes

Kim

et al. 2014

Trans. Vis. Sci. Tech.

Self Cite

View full text Add to dashboard Cite

Citation: Pardue MT, Barnes CS, Kim MK, et al. Rodent hyperglycemiainduced inner retinal defects are mirrored in human diabetes. Tran Vis Sci Tech. 2014;3(3):6, http:// tvstjournal.org/doi/full/10. 1167/tvst. 3.3.6, doi:10.1167/tvst.3.3.6 Purpose: To evaluate the utility of low luminance stimuli to functionally probe inner retinal rod pathways in the context of diabetes mellitus in both rat and human subjects.Methods: Inner retinal dysfunction was assessed using oscillatory potential (OP) delays in diabetic rats. Scotopic electroretinograms (ERGs) in response to a series of increasing flash luminances were recorded from streptozotocin (STZ)-treated and control Sprague-Dawley rats after 7, 14, 20, and 29 weeks of hyperglycemia. We then evaluated OP delays in human diabetic subjects with (DR) and without (DM) diabetic retinopathy using the International Society for Clinical Electrophysiology in Vision (ISCEV) standard scotopic protocol and two additional dim test flashes.Results: Beginning 7 weeks after STZ, OP implicit times in diabetic rats were progressively delayed in response to dim, but not bright stimuli. In many diabetic subjects the standard ISCEV dim flash failed to illicit measureable OPs. However, OPs became measurable using a brighter, nonstandard dim flash (Test Flash 1, À1.43 log cd s/m 2 ), and exhibited prolonged implicit times in the DM group compared with control subjects (CTRL).Conclusions: Delays in scotopic OP implicit times are an early response to hyperglycemia in diabetic rats. A similar, inner retinal, rod-driven response was detected in diabetic human subjects without diabetic retinopathy, only when a nonstandard ISCEV flash intensity was employed during ERG testing.Translational Relevance: The addition of a dim stimulus to standard ISCEV flashes with assessment of OP latency during ERG testing may provide a detection method for early retinal dysfunction in diabetic patients.

show abstract

Section: Erg Testing and Analysis In Ratsmentioning

confidence: 99%

Rodent Hyperglycemia-Induced Inner Retinal Deficits are Mirrored in Human Diabetes

Pardue

Barnes

Kim

et al. 2014

Trans. Vis. Sci. Tech.

Self Cite

View full text Add to dashboard Cite

show abstract

“…We assessed retinal function every four weeks starting from baseline, using ERG as previously detailed (Mocko et al, 2011). Briefly, rats were dark-adapted overnight and anesthetized [ketamine (60 mg/kg)/xylazine (7.5 mg/kg)] under dim red light.…”

Section: Methodsmentioning

confidence: 99%

“…Amplitudes were manually measured for a- and b-waves, PII and oscillatory potentials (OP1-4), as previously described (Mocko et al, 2011). Dark-adapted a-waves, which originates in the rod photoreceptors (Hood and Birch, 1990), were measured from the baseline to the trough of the first negative wave.…”

Section: Methodsmentioning

confidence: 99%

“…OPs were digitally filtered using the ERG system software (75–500 Hz; EM Version 8.1.2, 2008; LKC), and manually measured from trough to peak. Scotopic PII was also filtered and measured, as previously described (Mocko et al, 2011). Baseline ERG testing was conducted before commencement of treatment, and then at 4 weeks, 8 weeks, 12 weeks, and 17 weeks during treatment.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Whole-eye electrical stimulation therapy preserves visual function and structure in P23H-1 rats

Hanif

Kim

Thomas

et al. 2016

Experimental Eye Research

Self Cite

View full text Add to dashboard Cite

Low-level electrical stimulation to the eye has been shown to be neuroprotective against retinal degeneration in both human and animal subjects, using approaches such as subretinal implants and transcorneal electrical stimulation. In this study, we investigated the benefits of whole-eye electrical stimulation (WES) in a rodent model of retinitis pigmentosa. Transgenic rats with a P23H-1 rhodopsin mutation were treated with 30 min of low-level electrical stimulation (4 μA at 5 Hz; n = 10) or sham stimulation (Sham group; n = 15), twice per week, from 4 to 24 weeks of age. Retinal and visual functions were assessed every 4 weeks using electroretinography and optokinetic tracking, respectively. At the final time point, eyes were enucleated and processed for histology. Separate cohorts were stimulated once for 30 min, and retinal tissue harvested at 1 h and 24 h post-stimulation for real-time PCR detection of growth factors and inflammatory and apoptotic markers. At all time-points after treatment, WES-treated rat eyes exhibited significantly higher spatial frequency thresholds than untreated eyes. Inner retinal function, as measured by ERG oscillatory potentials (OPs), showed significantly improved OP amplitudes at 8 and 12 weeks post-WES compared to Sham eyes. Additionally, while photoreceptor segment and nuclei thicknesses in P23H-1 rats did not change between treatment groups, WES-treated eyes had significantly greater numbers of retinal ganglion cell nuclei than Sham eyes at 20 weeks post-WES. Gene expression levels of brain-derived neurotrophic factor (BDNF), caspase 3, fibroblast growth factor 2 (FGF2), and glutamine synthetase (GS) were significantly higher at 1 h, but not 24 h after WES treatment. Our findings suggest that WES has a beneficial effect on visual function in a rat model of retinal degeneration and that post-receptoral neurons may be particularly responsive to electrical stimulation therapy.

show abstract

“…Visual responses were more robust within the area of the implant when compared to control RCS rats. In contrast, the Mertk mouse, which has a similar mutation as the RCS rat, did not show a neuroprotective effect from an implanted mPVA (Mocko et al, 2011). In addition to effects of prosthetic devices, electrical stimulation has been reported to protect axotomized RGCs (Morimoto et al, 2005), preserve photoreceptors (Ni et al, 2009, Morimoto et al, 2012 and increase ERG amplitudes (Ni et al 2009).…”

Section: Neuroprotective Effects Of Prosthetic Devices and Electricalmentioning

confidence: 98%

The retina-prosthesis interface in two rat models of retinitis pigmentosa and functional changes associated with photoreceptor loss.

Fransen

View full text Add to dashboard Cite

Effects of Subretinal Electrical Stimulation in Mer-KO Mice

Cited by 23 publications

References 64 publications

Rodent Hyperglycemia-Induced Inner Retinal Deficits are Mirrored in Human Diabetes

Rodent Hyperglycemia-Induced Inner Retinal Deficits are Mirrored in Human Diabetes

Whole-eye electrical stimulation therapy preserves visual function and structure in P23H-1 rats

The retina-prosthesis interface in two rat models of retinitis pigmentosa and functional changes associated with photoreceptor loss.

Contact Info

Product

Resources

About