DENDRITE LABELED FULL
DENDRITE LABELED TRIAL

12Fluorescence videos were acquired with confocal pinhole diameters of 6.2 μm and 9.3 μm at the retina or 3.97 and 5.95 Airy disc radii. Because of the weak fluorescence signal from the retina, 400 to 1000 raw video frames were dual registered and averaged using methods described in Gray et al. The images in monkeys 1 and 2 were taken at eccentricities of approximately 20° to 30°, where ganglion cell dendrites are typically larger and have wider branching patterns than locations closer to the fovea.

DENDRITE LABELED TRIAL

Standard ophthalmic trial lenses were used to correct residual astigmatism and defocus to values that could be corrected with the deformable mirror (typically <0.75 μm root mean square (RMS) over a 5.8- to 6.1-mm pupil in both monkeys). Each monkey was fitted with a rigid, gas-permeable contact lens to reduce astigmatism and defocus. Over a 6-mm entrance pupil diameter, the equivalent NA was between 0.229 and 0.238, compared with 0.18 for a typical human eye. 10However, the functional role of many other retinal ganglion cell types cannot easily be disentangled in this way, prompting the need for a better method to distinguish these cells in the living eye.ġ/ − 1/power(D)} × 10 6, where the power in diopters has been calculated by linearly scaling eye size by the measured axial length. It has been possible to examine the different functional contributions of the parvocellular and magnocellular pathways to vision because they are anatomically segregated in the lateral geniculate nucleus (LGN), allowing psychophysical measurements in monkeys after selective lesioning. 7 ), and these studies must be supplemented by investigations in the living primate. The function of primate retinal ganglion cells has received detailed scrutiny recently with the use of in vitro methods (see, for example, Dacey et al. Detailed description of the morphology and physiology of primate ganglion cells have been carried out by Rodieck and Watanabe, 4Watanabe and Rodieck, 5and Dacey et al., 6 7 8 9resulting in the identification of more than 20 different retinal ganglion cell types. Imaging retinal ganglion cells is of special importance because it offers the possibility of directly observing the function of myelinated, spiking neurons of the central nervous system in the normal and diseased retina. Similar approaches may be applied to image other relatively transparent retinal structures, providing a potentially valuable tool for microscopic examination of the normal and diseased living retina. This in vivo method applied to ganglion cells demonstrates that structures smaller than the somas of typical retinal cells can be accessible in living eyes. The axial positional accuracy of fluorescence- labeled objects was approximately 4 μm.Ĭonclusions.

DENDRITE LABELED FULL

The full width at half maximum of the transverse line spread function (LSF) was 1.6 μm, and that of the axial point spread function (PSF) was 115 μm. Axons and dendritic arborization could be resolved in primate retinal ganglion cells in vivo, comparing favorably in detail with ex vivo confocal images of the same cells.

Fluorescence images of the ganglion cells were obtained in vivo with an adaptive optics scanning laser ophthalmoscope. Macaque retinal ganglion cells were labeled with retrograde transport of rhodamine dextran injected into the lateral geniculate nucleus. The extent to which the fine structure of single ganglion cells, such as dendrites and axons, can be resolved in retinal images obtained from the living primate eye was investigated.

Dendrite labeled