We hypothesized that cyclophosphamide- (CYP-) induced cystitis results in oxidative stress and contributes to urinary bladder dysfunction. We determined (1) the expression of oxidative stress markers 3-nitrotyrosine (3-NT), reactive oxygen species (ROS)/reactive nitrogen species (RNS), inflammatory modulators, neuropeptides calcitonin gene-related peptide (CGRP), substance P (Sub P), and adenosine triphosphate (ATP) that contribute to the inflammatory process in the urinary tract and (2) the functional role of oxidative stress in urinary bladder dysfunction with an antioxidant, Tempol, (1 mM in drinking water) combined with conscious cystometry. In CYP-treated (4 hr or 48 hr; 150 mg/kg, i.p.) rats, ROS/RNS and 3-NT significantly (P ≤ 0.01) increased in urinary bladder. CYP treatment increased ATP, Sub P, and CGRP expression in the urinary bladder and cystometric fluid. In CYP-treated rats, Tempol significantly (P ≤ 0.01) increased bladder capacity and reduced voiding frequency compared to CYP-treated rats without Tempol. Tempol significantly (P ≤ 0.01) reduced ATP expression, 3-NT, and ROS/RNS expression in the urinary tract of CYP-treated rats. These studies demonstrate that reducing oxidative stress in CYP-induced cystitis improves urinary bladder function and reduces markers of oxidative stress and inflammation.

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Populations harbour enormous genetic diversity in ecologically important traits. Understanding the processes that maintain this variation is a longstanding challenge in evolutionary biology. Recent evidence indicates that a mating preference for novel sexual signals can be a powerful force maintaining genetic diversity. However, the proximate underpinnings of this preference, and its generality, remain unclear. Here, we test the hypothesis that preference for novel sexual signals is underpinned by habituation, a nearly ubiquitous form of learning whereby individuals become less responsive to repetitive stimuli. We use the Trinidadian guppy (Poecilia reticulata), in which male colour patterns are diverse yet heritable. We show that repeated exposure to males with a given colour pattern reduces female interest in males with that pattern, and that interest recovers following brief isolation. These results fulfil two core criteria of habituation: responsiveness decline and spontaneous recovery. To distinguish habituation from sensory adaptation and fatigue, we also demonstrate stimulus specificity and dishabituation. These results provide the first evidence that habituation causes a preference for novel sexual signals, addressing the mechanistic underpinnings of this mating preference. Given the pervasiveness of habituation among taxa and sensory contexts, our findings suggest that preference for novelty may play an underappreciated role in mate choice and the maintenance of genetic variation.

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Color variation is one of the most obvious examples of variation in nature. Objective quantification and interpretation of variation in color and complex patterns is challenging. Assessment of variation in color patterns is limited by the reduction of color into categorical measures and lack of spatial information. We present Colormesh as a novel method for analyzing complex color patterns that offers unique capabilities. Compared to other methods, Colormesh maintains the continuous measure of color at individual sampling points throughout the pattern. This is particularly useful for analyses of variation in color patterns, whether interest is in specific locations or the pattern as a whole. In our approach, the use of Delaunay triangulation to determine sampling location eliminates the need for color patterns to have clearly defined pattern elements, and users are not required to identify discrete color categories. This method is complementary to several other methods available for color pattern quantification, and can be usefully deployed to address a wide range of questions about color pattern variation.