AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Plexiform layers11/30/2023 ![]() This scheme is also paralleled by synapse density ( Koontz and Hendrickson, 1987), and dendritic tree distributions of cell types such as midget ganglion cells ( Dacey, 1993). In the primate retina, bipolar cell ramifications ( Mariani, 1984 Boycott and Wässle, 1991 Kolb et al., 1992), assessed by Golgi staining, and neurotransmitters ( Marc, 1986), assessed by autoradiography and immunostaining, support a pentalaminar organization. This pentalaminar scheme for describing the IPL, initially based on Müller glia transverse processes ( Cajal, 1893 Polyak, 1941), has now become a de facto convention. The IPL is often further divided into 5 strata of approximately equal thickness, with the two innermost strata corresponding to the ON pathway (sublamina A), the two outermost strata corresponding to the OFF pathway (sublamina B), and the middle stratum designated as either ON or as a watershed zone ( Balasubramanian and Gan, 2014). Additionally, each synaptic layer is further stratified the OPL is divided into rod and cone synapses ( Kolb, 1977), while the IPL is divided into ON (sublamina B) and OFF (sublamina A) bipolar cell axon terminations, which give rise to ON and OFF channels ( Famiglietti and Kolb, 1976 Nelson et al., 1978) that nominally respond to light increments and decrements, respectively. The IPL contains synapses between bipolar cells, amacrine cells, and the output ganglion cells. The OPL contains synapses between the rod and cone photoreceptors and bipolar cells, with lateral interactions provided by horizontal cells. For example, synapses are segregated from cell somas along the depth axis of the retina, being organized into two major layers: the outer plexiform layer (OPL) and the inner plexiform layer (IPL). The function of the retina naturally gives rise to retinal stratification ( Wassle, 2004), or laminar organization of neural circuitry that processes visual signals. The retina transmits and filters light-evoked signals from the two-dimensional photoreceptor mosaic to the output ganglion cells that relay visual signals to the brain. Topographic variations should be carefully considered when designing studies in development or diseases of the visual system. This proposed correlate of IPL stratification is accessible through non-invasive ocular imaging in living humans. We characterize the topography of this reflectivity pattern non-invasively in a cohort of normal, young adult human subjects. Here, employing ultrahigh resolution visible light Optical Coherence Tomography (OCT) imaging in humans, we report a stereotyped reflectivity pattern of the inner plexiform layer (IPL) that parallels IPL stratification. Yet, to our knowledge, there is no way to directly assess this anatomical stratification in vivo. ![]() These two pathways are spatially segregated along the depth axis of the retina. 5Tech4Health Institute, NYU Langone Health, New York, NY, United Statesįrom the bipolar cells to higher brain visual centers, signals in the vertebrate visual system are transmitted along parallel on and off pathways.4Department of Radiology, NYU Langone Health, New York, NY, United States.3Department of Ophthalmology, NYU Langone Health, New York, NY, United States.2Department of Ophthalmology and Vision Science, School of Medicine, University of California, Davis, Sacramento, CA, United States.1Department of Biomedical Engineering, University of California, Davis, Davis, CA, United States. ![]()
0 Comments
Read More
Leave a Reply. |