Glaucoma is a common cause of blindness characterized by the degeneration of optic nerve and retinal ganglion cells (RGC). A longstanding question in glaucoma research is whether certain RGC types are more susceptible to glaucoma than other RGC types. It is well understood that the mammalian retina contains a diverse population of RGCs - humans have ̃20 distinct RGC types; each cell type exhibits unique morphological and physiological properties. Given the diversity of RGC types in the retina, it is plausible that different cell types respond differently to glaucoma and thus, certain cell types may degenerate at earlier time points than others. Determining whether specific RGC types degenerate at earlier time points can have important clinical impact on early detection and treatment of glaucoma. To study whether certain RGC types degenerate at earlier time points, we used a large-scale multi-electrode system to record the action potentials of hundreds of RGCs simultaneously in healthy and optic nerve crushed rat retinas. ̃9 distinct RGC types were identified in the healthy rat retina based on unique light response and intrinsic spiking properties. The results in the healthy rat retina were compared to the optic nerve crushed rat retina to assess whether certain RGC types degenerated at earlier time points following optic nerve crush. The current results show that 2 RGC types degenerate selectively at ̃10 days after optic nerve crush

BACKGROUND: Twelve weeks of weekly isoniazid and rifapentine (3HP) prevents TB disease among people with HIV (PWH), but the costs to people of taking TB preventive treatment is not well described.METHODS: We surveyed PWH who initiated 3HP at a large urban HIV/AIDS clinic in Kampala, Uganda, as part of a larger trial. We estimated the cost of one 3HP visit from the patient perspective, including both out-of-pocket costs and estimated lost wages. Costs were reported in 2021 Ugandan shillings (UGX) and US dollars (USD; USD1 = UGX3,587)RESULTS: The survey included 1,655 PWH. The median participant cost of one clinic visit was UGX19,200 (USD5.36), or 38.5% of the median weekly income. Per visit, the cost of transportation was the largest component (median: UGX10,000/USD2.79), followed by lost income (median: UGX4,200/USD1.16) and food (median: UGX2,000/USD0.56). Men reported greater income loss than women (median: UGX6,400/USD1.79 vs. UGX3,300/USD0.93), and participants who lived further than a 30-minute drive to the clinic had higher transportation costs than others (median: UGX14,000/USD3.90 vs. UGX8,000/USD2.23).CONCLUSION: Patient-level costs to receive 3HP accounted for over one-third of weekly income. Patient-centered approaches to averting or defraying these costs are needed.