Purpose: To determine the extent of retinal ganglion cell loss and morphologic abnormalities in surviving ganglion cells in Ins2 Akita/+ diabetic mice.
Methods: Mice that expressed cyan fluorescent protein (CFP) or yellow fluorescent protein (YFP) reporter genes under the transcriptional control of the Thy1 promoter were crossed with Ins2 Akita/+ mice. After 3 months of diabetes, the number and morphology of retinal ganglion cells was analyzed by confocal microscopy. The number of CFP-positive retinal ganglion cells was quantified in retinas of Ins2(Akita/+) Thy1-CFP mice. The morphology of surviving cells was examined, and dendritic density was quantified in Ins2 Akita/+ Thy1-YFP mice by using the Sholl analysis.
Results: Thy1-CFP expression was limited to retinal ganglion cell bodies. There was a 16.4% reduction in the density of CFP-positive ganglion cells in the peripheral retina of Ins2 Akita/+ mice compared with wild-type control retinas (P < 0.017), but no significant change in the central retina. Thy1-YFP expression occurred throughout the entire structure of a smaller number of cells, including their soma, axons, and dendrites. Six different morphologic clusters of cells were identified in the mouse retinas. The structure of dendrites of ON-type retinal ganglion cells was affected by diabetes, having 32.4% more dendritic terminals (P < 0.05), 18.6% increase in total dendrite length (P < 0.05), and 15.3% greater dendritic density compared with control retinas, measured by Scholl analysis. Abnormal swelling on somas, axons, and dendrites were noted in all subtypes of ganglion cells including those expressing melanopsin.
Conclusions: The data show that retinal ganglion cells are lost from the peripheral retina of mice within the first 3 months of diabetes and that the dendrites of surviving large ON-type cells undergo morphologic changes. These abnormalities may explain some of the early anomalies in visual function induced by diabetes.
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http://dx.doi.org/10.1167/iovs.07-0683 | DOI Listing |
Nat Commun
December 2024
Department of Ophthalmology and Stein Eye Institute, UCLA David Geffen School of Medicine, Los Angeles, CA, USA.
The lamprey, a primitive jawless vertebrate whose ancestors diverged from all other vertebrates over 500 million years ago, offers a unique window into the ancient formation of the retina. Using single-cell RNA-sequencing, we characterize retinal cell types in the lamprey and compare them to those in mouse, chicken, and zebrafish. We find six cell classes and 74 distinct cell types, many shared with other vertebrate species.
View Article and Find Full Text PDFNat Commun
December 2024
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Currently there are no effective treatments for an array of neurodegenerative disorders to a large part because cell-based models fail to recapitulate disease. Here we develop a reproducible human iPSC-based model where laser axotomy causes retrograde axon degeneration leading to neuronal cell death. Time-lapse confocal imaging revealed that damage triggers an apoptotic wave of mitochondrial fission proceeding from the site of injury to the soma.
View Article and Find Full Text PDFJ Neurosci Res
January 2025
International School of Medicine, University of Health Sciences, Istanbul, Turkey.
Neurological diseases are central nervous system (CNS) disorders affecting the whole body. Early diagnosis of the diseases is difficult due to the lack of disease-specific tests. Adding new biomarkers external to the CNS facilitates the diagnosis of neurological diseases.
View Article and Find Full Text PDFJ Neurosci Res
January 2025
Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico, Mexico.
Lateralization of motor behavior, a common phenomenon in humans and several species, is modulated by the basal ganglia, a site pointed out for the interhemispheric differences related to lateralization. Our study aims to shed light on the potential role of the striatonigral D1 receptor in functional asymmetry in normal conditions through neurochemical and behavioral means. We found that D1 receptor activation and D1/D3 receptor coactivation in striatonigral neurons leads to more cAMP production by adenylyl cyclase in the striatum and GABA release in their terminals in the right hemisphere compared to the left.
View Article and Find Full Text PDFMol Med
December 2024
Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, 197 Ruijin er Road, Shanghai, 200025, China.
Background: Glaucoma is a group of heterogeneous neurodegenerative diseases with abnormal energy metabolism and imbalanced neuroinflammation in the retina. Thioredoxin-interacting protein (TXNIP) is involved in glucose and lipid metabolism, and associated with oxidative stress and inflammation, however, not known whether to be involved in glaucoma neuropathy and its underlying mechanisms.
Methods: To establish the chronic ocular hypertension (COH) mice model.
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