Showing papers on "Retinal ganglion cell published in 1970"
TL;DR: It is suggested that the amacrine cell is involved in mediating complex visual transformations in certain vertebrate retinas in those animals which are known to have relatively complex retinal ganglion cell receptive field properties.
Abstract: The inner plexiform layer of human, monkey, cat, rat, rabbit, ground squirrel, frog and pigeon retinas was studied by electron microscopy. All showed the same qualitative synaptic arrangements: bipolar cells made dyad ribbon synapses onto amacrine and ganglion cells; amacrine cells made conventional synaptic contacts onto bipolar, ganglion cells; amacrine cells montage of electron micrographs through the full thickness of the inner plexiform layer were made for each species and were scored for synaptic contacts. Both absolute and relative quantitative differences were found between species. The ratio of amacrine cell (conventional) synapses to bipolar cell (ribbon) synapses, the absolute number of amacrine cell synapses and the number of inter-amacrine cell synapses were all found to be higher in those animals which are known to have relatively complex retinal ganglion cell receptive field properties. It is suggested that the amacrine cell is involved in mediating complex visual transformations in certain vertebrate retinas.
285 citations
TL;DR: Response characteristics of the previously categorized four types of cat retinal ganglion cells were investigated using light and dark spot stimuli by recordings of unit discharges from the optic tract, and phasic and tonic nature of these four type of cells were further clarified.
Abstract: Response characteristics of the previously categorized four types of cat retinal ganglion cells (ON-I, OFF-I, ON-II and OFF-II) were investigated using light and dark spot stimuli by recordings of unit discharges from the optic tract, and phasic and tonic nature of these four types of cells were further clarified. ON-I and OFF-I are phasic in nature and respond to only a transient increase and decrease in luminance, respectively. ON-II and OFF-II are tonic and continue to respond to a stationary light and dark contrast, respectively. Besides, a difference is also found between ON-I and ON-II in the firing patterns of the transient response to a bright spot stimulus. ON-I responds to the onset of a bright spot with an initial burst followed by dispersed discharges. In ON-II's transient response, initial discharge rate is as high as that of ON-I's burst, but in contrast with the case of ON-I's response, the discharge rate gradually decreases toward a mean rate of sustained responses to the spot.
43 citations
TL;DR: In tadpole frog retina, the development of four classes of visual form detectors matched the growth of four types of ganglion cell dendritic trees, which provides the code for detection of visual shapes.
Abstract: In tadpole frog retina, the development of four classes of visual form detectors matched the growth of four types of ganglion cell dendritic trees. From this correlation of electrophysiology and anatomy we concluded that the structure of retinal ganglion cell dendritic trees provides the code for detection of visual shapes.
34 citations
TL;DR: It is concluded that the cat retinal ganglion cell gives a more precise representation of intensity changes in the low contrast range than in the high contrast range and that the intensity code is non-linear for theLow contrast range.
28 citations
TL;DR: The organization of the ‘Westheimer function’ in the retina has been further analysed and it is placed that the locus of the measured inhibitory component of the Westheimer function most probably in the inner retina.
Abstract: The organization of the ‘Westheimer function’ in the retina has been further analysed. Patients with sharp visual field cuts caused by chiasmal and cortical lesions have been studied. Data were generally obtained from points approximately 10°–15° from the fovea (where areas of spatial interaction and the magnitude of the inhibitory component were large). The center of the three field display was placed just within the boundary of the sighted area of the visual field. Hence, a substantial part of the background field fell on nonsighted areas, which presumably retained retinal function. If the inhibitory part of the function originates proximal to the retinal ganglion cell layer (or the underlying retina was nonfunctional), then the basic ‘Westheimer function’ probably would be altered when these data are compared with findings obtained at a normal point in the visual field of the affected eye. All cases measured to date exhibited essentially unaltered functions. This finding, plus previous studies of patients with inner retinal diseases, places the locus of the measured inhibitory component of the Westheimer function most probably in the inner retina.
19 citations