Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-7-20
pubmed:abstractText
We have used the P23H line 1 homozygous albino rat to study how progressive photoreceptor degeneration affects rod and cone relay pathways. We examined P23H retinas at different stages of degeneration by confocal microscopy of immunostained sections and electroretinogram (ERG) recordings. By 21 days of age in the P23H rat retina, there is already substantial loss of rods and reduction in rod bipolar dendrites along with reduction of metabotropic glutamate receptor 6 (mGluR6) and rod-associated bassoon staining. The cone pathway is relatively unaffected. By 150 days, when rods are absent from much of the retina, some rod bipolars remain and dendrites of rod and cone bipolar cells form synaptic complexes associated with cones and horizontal cell processes. These complexes include foci of mGluR6 and bassoon staining; they develop further by 270 days of age. Over the course of degeneration, beginning at 21 days, bipolar axon terminals atrophy and the inner retina undergoes further changes including a reduced and disorganized AII amacrine cell population and thinning of the inner plexiform layer. Electroretinogram (ERG) results at 23 days show reductions in a-wave amplitude, in rod and cone-associated b-waves (using a double flash paradigm) and in the amplitude of oscillatory potentials (OPs). By 38 days, rod scotopic a-wave responses and OPs are lost. B-wave amplitudes decline until 150 days, at which point they are purely cone-driven and remain stable up to 250 days. The results show that during the course of photoreceptor loss in the P23H rat, there are progressive degenerative changes, particularly in the rod relay pathway, and these are reflected in the changing ERG response patterns. Later reactive changes involving condensation of cone terminals and neurotransmitter receptors associated with rod and cone bipolar dendrites and with horizontal cell processes suggest that at this stage, there are likely to be complex changes in the relay of sensory information through the retina.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
127
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
301-17
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:15262321-Amacrine Cells, pubmed-meshheading:15262321-Animals, pubmed-meshheading:15262321-Animals, Genetically Modified, pubmed-meshheading:15262321-Dendrites, pubmed-meshheading:15262321-Disease Models, Animal, pubmed-meshheading:15262321-Electroretinography, pubmed-meshheading:15262321-Immunohistochemistry, pubmed-meshheading:15262321-Membrane Potentials, pubmed-meshheading:15262321-Microscopy, Confocal, pubmed-meshheading:15262321-Nerve Degeneration, pubmed-meshheading:15262321-Nerve Tissue Proteins, pubmed-meshheading:15262321-Neural Pathways, pubmed-meshheading:15262321-Presynaptic Terminals, pubmed-meshheading:15262321-Rats, pubmed-meshheading:15262321-Rats, Sprague-Dawley, pubmed-meshheading:15262321-Receptors, Metabotropic Glutamate, pubmed-meshheading:15262321-Retinal Cone Photoreceptor Cells, pubmed-meshheading:15262321-Retinal Degeneration, pubmed-meshheading:15262321-Retinal Rod Photoreceptor Cells, pubmed-meshheading:15262321-Vision, Ocular
pubmed:year
2004
pubmed:articleTitle
Regressive and reactive changes in the connectivity patterns of rod and cone pathways of P23H transgenic rat retina.
pubmed:affiliation
Departamento de Biotecnologia, Universidad de Alicante, San Vicente, del Raspeig, 3060, Alicante, Spain.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't