Abnormalities in rod photoreceptors, amacrine cells, and horizontal cells in human retinas with retinitis pigmentosa.
OBJECTIVE
To evaluate changes in the rods and amacrine cells and horizontal cells in human retinas with retinitis pigmentosa.


METHODS
Seven retinas from patient donors with retinitis pigmentosa and 14 age- and postmortem-matched normal human retinas were processed for immunocytochemistry and confocal microscopy. The following cell-specific antibodies were used: anti-rhodopsin (rods), anti-gamma-aminobutyric acid (amacrine cells), anticalbindin (cones and horizontal cells), anti-glial fibrillary acidic protein (astrocytes and reactive Müller cells), and anti-synaptophysin and anti-SV2 (synaptic vesicles).


RESULTS
In retinal regions with significant photoreceptor loss, the rods, gamma-aminobutyric acid-positive amacrine cells, and calbindin-positive horizontal cells had undergone neurite sprouting. The rod, amacrine and horizontal cell neurites were associated with the surfaces of glial fibrillary acidic protein-immunoreactive Müller cells. Most rod neurites that projected into the inner retina contacted the somata of gamma-aminobutyric acid-positive amacrine cells.


CONCLUSIONS
Rods, amacrine and horizontal cells undergo neurite sprouting in human retinas with retinitis pigmentosa. These changes in the retinal neurons may contribute to the electroretinographic abnormalities and progressive decline in vision noted by patients with retinitis pigmentosa. These alterations may also complicate strategies for treatment of retinitis pigmentosa.
Fariss
R N
RN
Department of Ophthalmology, University of Washington, Seattle, USA.
Li
Z Y
ZY
Milam
A H
AH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D064026:Calbindins; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D016501:Neurites / Q000378:metabolism / Q000473:pathology*; D009475:Neurons, Afferent / Q000378:metabolism / Q000473:pathology*; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism / Q000473:pathology*; D012174:Retinitis Pigmentosa / Q000378:metabolism / Q000473:pathology*; D012243:Rhodopsin / Q000378:metabolism; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D013572:Synaptic Vesicles / Q000378:metabolism; D016708:Synaptophysin / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D064026:Calbindins; D005904:Glial Fibrillary Acidic Protein; D064030:S100 Calcium Binding Protein G; D016708:Synaptophysin; D005680:gamma-Aminobutyric Acid; D012243:Rhodopsin