Document Detail

Chronic Delivery of Low-Level Exogenous CurrentPreserves Retinal Functionin Pigmented P23H Rat.
MedLine Citation:
PMID:  23147691     Owner:  NLM     Status:  Publisher    
Diffuse electrical currents delivered to the eye were investigated in a rat model of retinitis pigmentosa for potentially therapeutic effects. Low-level currents were passed between electrodes placed on the cornea and in the mouth during 30-minute sessions two times per week from 4-16 weeks of age. Single-flash electroretinograms (ERG) were recorded and analyzed for amplitude and measures of sensitivity, and basic histology was performed. ERG a-wave amplitudes were slightly greater in treated vs. age-matched controls at 16 wks of age, but the combined thicknesses of the outer nuclear layer and outer segment layer were similar at this age. Treated animals exhibited a significant preservation of b-wave amplitudes, and a striking preservation of rod sensitivity, measured as the stimulus strength required to reach half-saturation of the a-wave. Analysis of the leading edge of the a-wave using a delayed Gaussian function revealed a decrease in the parameter reflecting gain of the phototransduction cascade over the 12-week course of treatment, and no significant change in control animals over the same period. These results suggest that while the exogenous currents failed to preserve the number or gross structure of rods, the responsivity of individual photoreceptors was relatively preserved, perhaps via an increase in efficiency of photon capture (R∗ / photon). This preserved functionality may delay the retraction of bipolar cell dendrites from degenerating photoreceptors.
Safa Rahmani; Les Bogdanowicz; Joel Thomas; John R Hetling
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-11-9
Journal Detail:
Title:  Vision research     Volume:  -     ISSN:  1878-5646     ISO Abbreviation:  Vision Res.     Publication Date:  2012 Nov 
Date Detail:
Created Date:  2012-11-13     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0417402     Medline TA:  Vision Res     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2012. Published by Elsevier Ltd.
Department of Bioengineering, University of Illinois at Chicago.
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