Purchase this article with an account.
G. Xu, Y. Qin, W. Wang; Morphology of Single Retinal Ganglion Cells in the First Three Months of Streptozotocin –Induced Diabetes . Invest. Ophthalmol. Vis. Sci. 2005;46(13):430.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To examine the morphological changes of rat retinal ganglion cells (RGCs) , including dendritic field and soma, at 1 month and 3 months after diabetes induced. Methods: The rat model of diabetes was confirmed by assaying the glucose concentration in blood with glucose levels of greater than 16.7mmol/L 3 days after intraperitoneal injection of streptozotocin. 20 diabetic rats at each time and 20 adult normal rats were sacrified. The retinae were isolated and a BioRad PDS–10000 He Biolistic particle delivery system (gene gun) was used to propel the DiI dye–coated tungsten particles into the wholemount retina. After the somata and dendritic fields of the RGCs labeled, images of RGCs were collected using a Leica DMRA microscope equipped with a Spot cooled CCD camera . RGCs were identified by the unequivocal presence of an axon. To quantify soma size, a circle was fit to the soma and its area was calculated using a graphic program MetaMorph (Universal Imaging, West Chester, PA). For dendritic–field size, a convex polygon was drawn by linking the tips of dendrites, and the area calculated. We classified RGCs with a large soma and a large dendritic field as RGA, cells with a small– to medium–sized soma and a small– to medium–sized dendritic field as RGB, and cells with a small– to medium–sized soma but a medium–to–large dendritic field RGC. Results: Totally 351 RGCs from 40 retinae in the normal rats, 223 RGCs from 35 retinae in the 1–month diabetic rats and 369 RGCs from 36 retinae in the 3–month diabetic rats were imaged and classified into RGA, RGB and RGC .Increases , decreases and obvious damage in dendritic fields were all observed in early diabetic rat RGCs and RGCs with one part dendrites shrinking while another part expanding, but without obvious soma changes, were also found in this study. The dendritic changes we observed were more sensitive to diabetes than soma and significant increases in the mean diameter of dendritic fields of classified RGAs (P=0.00042) and RGCs (P=0.0063) were detected, but not RGBs (P= 0.082) in 3–month diabetic rats . Conclusions: In short term diabetes, injuries of RGCs were confirmed and dendrites of RGCs showed good plasticity in adult diabetic rats .The injury and response was different as to RGC types ,with RGAs> RGCs >RGBs. Dying and surviving RGCs with compensatory coexist in the same retina. The dendritic change preceded anatomic change at the level of the cell soma indicates that the onset of RGC injury in diabetes occurred earlier than previous thought, based on estimates of RGCs loss alone and also suggests a window of opportunity for effective neuroprotection.
This PDF is available to Subscribers Only