mfERG in normal and lesioned rabbit retina

Abstract

This study shows that the mfERG technique can be used as a tool in experimental retinal research involving the rabbit eye, where retinal lesions down to at least 1 mm can be detected. One difficulty involves scattering light emanating from the relatively large optic disc and the myelinated nerve fibers, which makes the use of a mfERG system, in which the fundus can be visualized during stimulation, mandatory.

Retinal function and PKC alpha expression after focal laser photocoagulation

“…The rabbit retina, however, does not include a macula, but instead a horizontally oriented visual streak where the cone concentration peaks at a mere 18000 cells/mm 2 [7]. Due to this comparatively low concentration of cones, a relatively severe lesion is required to obtain significant changes in the mfERG amplitudes [10]. We interpret the prolonged increased latency in mfERG recordings as an indicator of cone system related pathology related to cone photoreceptor damage induced by the laser treatment and conclude that this local effect, at least in the short term, is not reversible.…”

“…Postoperative examinations were made after 1, 3 and 5 weeks. The protocols for ERG and mfERG examination in the rabbit eye have been previously described, and will only be summarized here [10,11].…”

“…We also wanted to explore cellular mechanisms behind any change in PKC alpha expression, and if possible relate such change to GFAP expression. To this end, we have used standardized protocols for full-field ERG and mfERG before and after treatment, combined with PKC alpha and GFAP immunohistochemistry as well as PKC alpha real-time PCR [10,11].…”

Pharmacological dissection of multifocal electroretinograms of rabbits with Pro347Leu rhodopsin mutation

“…The pharmacological dissection of the mfERGs shows that the ON-bipolar cell response was enhanced in the Tg rabbits despite rod photoreceptor degeneration, while the OFFbipolar cell response was not signifi cantly different between Tg and WT rabbits. Gjörloff et al [20][21][22][23] applied multifocal electroretinography to rabbits with normal as well as diseased retinas, and showed it to be a useful tool for detecting local lesions in rabbit eyes. As best we know, our work is the fi rst study which pharmacologically dissects the mfERGs from rabbits.…”

“…However, it has mfERGs OF P347L RABBITS been reported that scattered light refl ected from the optic disc and myelinated nerve fi ber can obscure these two landmarks in rabbits. 21 The monitoring of the stimulus on the fundus during the recordings allowed us to stimulate the retina more precisely. We analyzed the latter part of the baseline mfERGs, such as P3, where the induced component could be contaminated.…”