Highlights d Natural scene discriminability in the V1 increases by 75% between the ages of 4 and 6 weeks d Discriminability of natural scenes and gratings is reduced in dark-reared animals d Discriminability fails to develop if visual experience is delayed until adulthood

45Locomotion has a global impact on circuit function throughout the cortex, including regulation of 46 spatiotemporal dynamics in primary visual cortex (V1). The mechanisms driving state-changes 47 in V1 result in a 2-3 fold gain of responsiveness to visual stimuli. To determine whether 48 locomotion-mediated increases in response gain improve the perception of spatial acuity we 49 developed a head-fixed task in which mice were free to run or sit still during acuity testing. 50 Spatial acuity, ranging from 0.1 to 0.7 cycles/°, was assessed before and after 3-4 weeks of 51 reward-based training in adult mice. Training on vertical orientations once a day improved the 52 average performance across mice by 22.5 ± 0.05%. Improvement transferred to non-trained 53 orientations presented at 45°, indicating that the improvement in acuity generalized. 54Furthermore we designed a second closed-loop task in which acuity threshold could be directly 55 assessed in a single session. Using this design, we established that acuity threshold matched 56 the upper limit of the trained spatial frequency; in two mice spatial acuity threshold reached as 57 high as 1.5 cycles/°. During the 3-4 weeks of training we collected a sufficient number of 58 stimulus trials in which mice performed above chance but below 100% accuracy. Using this 59 subset of stimulus trials, we found that perceptual acuity was not enhanced on trials in which 60 mice were running compared to trials in which mice were still. Our results demonstrate that 61 perception of spatial acuity is not improved by locomotion. 62 63In the acuity task, performance accuracy averaged across the first two baseline sessions 129 was greater than 0.7 at 0.46 cycles/° for all mice, and greater than 0.7 for half of the mice at 130 0.58 cycles/°, and less than 0.7 for all mice except one at 0.7 cycles/°. These performance 131 values are consistent with values obtained using the visual water task (Hosang et al., 2018; 132

CONTEXT Children with spina bifida are at high risk for urinary tract infections (UTI). However, there is no standardized definition of UTI in this population, leading to variability in both clinical management and research. This was highlighted in the 2013 systematic review on the same topic. OBJECTIVE Evaluate the frequency with which researchers are defining UTI in their studies of children with spina bifida and to determine what parameters are used. DATA SOURCES We searched Medline and Scopus databases for articles that included pediatric patients with spina bifida and used UTI as an outcome. STUDY SELECTION Exclusion criteria included publication before October 1, 2012, non-English language, and nonprimary research articles. DATA EXTRACTION Two independent reviewers each extracted data. RESULTS A total of 39 studies were included; 74% of these analyzed included an explicit definition of UTI. The most commonly used definition included a combination of symptoms and culture results (34.5%), whereas 31% used a combination of symptoms, culture results, and urinalysis data. Only 3.4% of articles used a urine culture alone to define UTI. CONCLUSIONS More articles that focus on children with spina bifida included a definition of UTI. However, significant variability persists in the definition of UTI in this patient population.

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The development of the visual system is known to be shaped by early-life experience. To identify response properties that contribute to enhanced natural scene representation, we performed calcium imaging of excitatory neurons in the primary visual cortex (V1) of awake mice raised in three different conditions (standard-reared, dark-reared, and delayed-visual experience) and compared neuronal responses to natural scene features relative to simpler grating stimuli that varied in orientation and spatial frequency. We assessed population selectivity in V1 using decoding methods and found that natural scene discriminability increased by 75% between the ages of 4 to 6 weeks. Both natural scene and grating discriminability were higher in standard-reared animals compared to those raised in the dark. This increase in discriminability was accompanied by a reduction in the number of neurons that responded to low-spatial frequency gratings. At the same time there was an increase in neuronal preference for natural scenes. Light exposure restricted to a 2-4 week window during adulthood did not induce improvements in natural scene nor in grating stimulus discriminability. Our results demonstrate that experience reduces the number of neurons required to effectively encode grating stimuli and that early visual experience enhances natural scene discriminability by directly increasing responsiveness to natural scene features.