Retinal bipolar cells spread their dendritic arbors to tile the retinal surface, extending them to the tips of the dendritic fields of their homotypic neighbors, minimizing dendritic overlap. Such uniform non-redundant dendritic coverage of these populations would suggest a degree of spatial order in the properties of their somal distributions, yet few studies have examined the patterning in retinal bipolar cell mosaics. The present study examined the organization of two types of cone bipolar cells in the mouse retina, the Type 2 cells and the Type 4 cells, and compared their spatial statistical properties with those of the horizontal cells and the cholinergic amacrine cells, as well as to random simulations of cells matched in density and constrained by soma size. The Delauney tessellation of each field was computed, from which nearest neighbor distances and Voronoi domain areas were extracted, permitting a calculation of their respective regularity indexes. The spatial autocorrelation of the field was also computed, from which the effective radius and packing factor were determined. Both cone bipolar cell types were found to be less regular and less efficiently packed than either the horizontal cells or cholinergic amacrine cells. Furthermore, while the latter two cell types had regularity indexes and packing factors in excess of those for their matched random simulations, the two types of cone bipolar cells had spatial statistical properties comparable to random distributions. An analysis of single labeled cone bipolar cells revealed dendritic arbors frequently skewed to one side of the soma, as would be expected from a randomly distributed population of cells with dendrites that tile. Taken together, these results suggest that, unlike the horizontal cells or cholinergic amacrine cells which minimize proximity to one another, cone bipolar cell types are constrained only by their physical size.

Amacrine cells of the retina are conspicuously variable in their morphologies, their population demographics, and their ensuing functions. Vesicular glutamate transporter 3 (VGluT3) amacrine cells are a recently characterized type of amacrine cell exhibiting local dendritic autonomy. The present analysis has examined three features of this VGluT3 population, including their density, local distribution, and dendritic spread, to discern the extent to which these are interrelated, using male and female mice. We first demonstrate that Bax-mediated cell death transforms the mosaic of VGluT3 cells from a random distribution into a regular mosaic. We subsequently examine the relationship between cell density and mosaic regularity across recombinant inbred strains of mice, finding that, although both traits vary across the strains, they exhibit minimal covariation. Other genetic determinants must therefore contribute independently to final cell number and to mosaic order. Using a conditional KO approach, we further demonstrate that Bax acts via the bipolar cell population, rather than cell-intrinsically, to control VGluT3 cell number. Finally, we consider the relationship between the dendritic arbors of single VGluT3 cells and the distribution of their homotypic neighbors. Dendritic field area was found to be independent of Voronoi domain area, while dendritic coverage of single cells was not conserved, simply increasing with the size of the dendritic field. Bax-KO retinas exhibited a threefold increase in dendritic coverage. Each cell, however, contributed less dendrites at each depth within the plexus, intermingling their processes with those of neighboring cells to approximate a constant volumetric density, yielding a uniformity in process coverage across the population.

Stroke hospitalization rates in the United States are unequally distributed across the population. Factors such as age, race, socioeconomic status, and sex are associated with different hospitalization rates for acute ischemic stroke (AIS). This study aimed to review the patterns in these rates from 2010 to 2020.<break><break>The National Inpatient Sample (NIS) was used to analyze patterns in AIS hospitalizations in the United States between 2010 and 2020 based on age, sex, race, region, stroke comorbidities, and income. <break><break>The overall rate of AIS hospitalization increased from 230 to 254 per 100,000 individuals(+10.4%) between 2010 and 2020. Initially, the rates declined from 2010 to 2015(230 to 227 per 100,000); however, from 2016 to 2020, the AIS hospitalization rates(AIS-HR)increased(242 to 254 per 100,000).The rate of AIS hospitalization increased significantly for individuals aged 2544 years(2537 per 100,000, +48.0%)and 4565 years(171235 per 100,000, +37.4%).AIS hospitalization rates remained relatively stable for individuals aged6584 years(669688 per 100,000, +3.7%)and declined for those over 85 years(20051756 per 100,000, -12.4%).Among sex comparisons, AIS hospitalization rates were stable in women(241250 per 100,000, +3.7%)and increased in men (270308 per 100,000, +14.1%).In terms of race, Blacks had the highest age-adjusted yearly hospitalization rate (437), followed by Whites (215) and Hispanics (207) per 100,000 in 2020. There was a stepwise increase in AIS hospitalization rates based on the Charlson Comorbidity Index (CCI), with White, Black, and Hispanic populations having AIS hospitalization rates of CCI 0 and 1 (533, 434, and 233), CCI 2 (2197, 2555, and 2125), and CCI 3 (5283, 5724, and 4767) per 100,000, respectively.<break><break>Although the overall AIS hospitalization rate increased between 2010 and 2020, there was an initial decline until 2015, followed by a resurgence. This resurgence in AIS hospitalization rates was driven by greater underlying comorbidities, with disproportionate increases observed in Black and Hispanic populations. Further population analyses and cohort studies are required to confirm our findings.

Background Multiple nerve transfer techniques are used to treat patients with nerve injuries when a primary repair is not possible. These techniques are categorized to end-to-end, end-to-side, and side-to-side neurorrhaphy. Our study aims to explore the utility of the cross-bridge ladder technique (H-shaped), which has shown promising results in animal models and probably underutilized clinically. Methods Four patients with significant loss of ankle dorsiflexion were seen in the clinic and underwent evaluation, including electrodiagnostic studies. A cross-bridge ladder repair technique was used between the tibial nerve as the donor and the common peroneal nerve as the recipient via one or two nerve grafts coapted in parallel with end-to-side neurorrhaphies. Dorsiflexion strength was measured preoperatively using the Medical Research Council (MRC) grading system and at each postoperative follow-up appointment. Results All four patients had suffered persistent and severe foot drop (MRC of 0) following trauma that had occurred between 6 and 15 months preoperatively. Three of the four patients improved to an MRC of 2 several months postoperatively. The last patient had an immediate improvement to an MRC of 2 by his first month and had a complete recovery of ankle dorsiflexion within 4 months from surgery. Conclusion We demonstrate the utility and clinical outcomes of the cross-bridge ladder technique in patients with persistent and prolonged foot drop following trauma. Both early and late recovery were seen while all patients regained motor function, with some patients continuing to improve up to the most recent follow-up.IRB Approval: Obtained 2013–1411-CP005