We thank the Lions NSW Vision Lender at Sydney Vision Hospital for making human donor eyes available

We thank the Lions NSW Vision Lender at Sydney Vision Hospital for making human donor eyes available. photopic spatial acuity, supporting the view that this P pathway underlies high-acuity spatial vision. Outside the fovea, array acuity of both OFF-midget Pungiolide A and OFF-DB cells exceeds psychophysical steps of photopic spatial acuity. We conclude that parasol and midget pathway bipolar cells deliver high-acuity spatial signals to the inner plexiform layer, but outside the fovea, this spatial resolution is usually lost at the level of ganglion cells. SIGNIFICANCE STATEMENT We make accurate maps of the spatial density and distribution of neurons in the human retina to aid in understanding human spatial vision, interpretation of diagnostic assessments, and the implementation of therapies for retinal diseases. Here, we map neurons involved with the midget-parvocellular (P pathway) and parasol-magnocellular (M pathway) through Pungiolide A human retina. We find that P-type bipolar cells outnumber M-type bipolar cells at all eccentricities. We show that cone photoreceptors and P-type pathway bipolar cells are tightly connected throughout the retina, but that spatial resolution is usually lost at the level of the ganglion cells. Overall, the results support the view that this P pathway is usually specialized to serve both high acuity vision and red-green color vision. is cell density, is the bin width, and is depth in the is usually cell density (cells/mm2), are exponential coefficients, and are multiplicative coefficients, and is eccentricity (mm). Unfavorable fit values in the fovea were set to zero. Cumulative density across the horizontal meridian was calculated by circular integration of spatial densities within annuli of defined eccentricity ranges, radiating from the foveal center in a bullseye pattern. The following formula was applied to calculate the number of cells within each annulus: represents the radius of the outer border and represents the radius of the inner border of the eccentricity range in question. Table 3. Best fit Gja4 parameters for pooled data was calculated for each measured cell populace using the formula is the Nyquist limit (cycles per degree), is the retinal magnification factor, and is the intercell distance. Intercell distance was calculated as is the populace spatial density (cells/mm2). For simplicity, we ignored the nonlinear relation of retinal magnification to eccentricity (Drasdo and Fowler, 1974); we used a constant magnification factor of 0.29 mm/. This simplification introduces maximum 10% overestimate of retinal magnification at 30; exact magnification values can be recovered by reference to Drasdo and Fowler (1974; Pungiolide A their Determine 5). Receptoral and postreceptoral displacement Receptoral displacement (Henle fiber Pungiolide A length) in temporal retina was decided using stacks of confocal images to trace the axons of individual cone photoreceptors to their synaptic terminal (cone pedicle). The horizontal distance between the cone pedicle and the soma was measured. Postreceptoral displacement Pungiolide A was measured as the horizontal distance from the midline of the dendritic tree (presumed location of the cone pedicle) of the bipolar cell to the midline of the bipolar axon terminal. Terminology Based on previous studies (Hendrickson, 2005; Provis et al., 2013; Strettoi et al., 2018; Lee et al., 2019), we employ the following definitions: foveal retina refers to a radius of 0.8 mm (5.5 diameter of visual angle), central retina refers to eccentricities up to 3.0 mm (first 10 radius of visual angle) where the ganglion cell layer is more than one cell thick, roughly equivalent to the diameter of the macula lutea (Boycott et al., 1987; Bringmann et al., 2018), mid-peripheral retina refers to eccentricities between 3.0 and 6 mm and eccentricities beyond 6 mm are referred to as far peripheral retina. Results Data were obtained from one male and five female human donor retinas aged from 30 to 60 years (Table 1). Retinas were free from any obvious pathology, and the yellow pigment of the macula lutea was readily distinguishable (which facilitated identification of the fovea before sectioning). We did not specifically address the question of age-related differences in the distribution of retinal neurons but observed that variation between retinas was.