Search

The mammalian retina is considered an autonomous circuit, yet work dating back to Ramon y Cajal indicates that it receives inputs from the brain. How such inputs affect retinal processing has remained unknown. We confirmed brain-to-retina projections of histaminergic neurons from the mouse hypothalamus. Histamine application ex vivo altered the activity of various retinal ganglion cells (RGCs), including direction-selective RGCs that gained responses to high motion velocities. These results were reproduced in vivo with optic tract recordings where histaminergic retinopetal axons were activated chemogenetically. Such changes could improve vision of fast-moving objects (e.g., while running), which fits with the known increased activity of histaminergic neurons during arousal. An antihistamine drug reduced optomotor responses to high-speed moving stimuli in freely moving mice. In humans, the same antihistamine nonuniformly modulated visual sensitivity across the visual field, indicating an evolutionary conserved function of the histaminergic system. Our findings expose a previously unappreciated role for brain-to-retina projections in modulating retinal function.

Eradication of Pseudomonas aeruginosa (PA) is critical in cystic fibrosis (CF) patients., Objectives: To determine eradication success rate of newly acquired PA and to identify characteristics associated with eradication failure., Methods: In an observational study, data from patients with newly acquired PA infection from 2007 to 2013 were collected. Clinical variables were compared in patients with and without successful eradication for ≥1year., Results: Of 183 patients out of 740 (25%) from 7 CF Centers that had newly acquired PA, eradication succeeded in 72%. Patients with the highest risk of failure had multi-resistant PA, fewer sputum cultures taken, were older, and were diagnosed at a later age. The risk of eradication failure increased by 1.3% with each year of delayed CF diagnosis; successful eradication increased by 17% with each additional sputum culture taken., Conclusions: Delayed detection of PA infection leading to delayed treatment and growth of multi-resistant organisms is associated with eradication failure., (Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)