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Background: Amphibians represent an important evolutionary transition from aquatic to terrestrial environments and they display a large variety of complex behaviors despite a relatively simple brain. However, their brain activity is not as well characterized as that of many other vertebrates, partially due to physiological traits that have made electrophysiology recordings difficult to perform in awake and moving animals., New Method: We implanted flexible mesh electronics in the cane toad ( Rhinella marina ) and performed extracellular recordings in the telencephalon of anesthetized toads and partially restrained, awake toads over multiple days., Results: We recorded brain activity over five consecutive days in awake toads and over a 15 week period in a toad that was anesthetized during recordings. We were able to perform spike sorting and identified single- and multi-unit activity in all toads., Comparison With Existing Methods: To our knowledge, this is the first report of a modern method to perform electrophysiology in non-paralyzed toads over multiple days, though there are historical references to short term recordings in the past., Conclusions: Implementing flexible mesh electronics in amphibian species will allow for advanced studies of the neural basis of amphibian behaviors., Competing Interests: 10.COMPETING INTERESTS The authors declare no competing or financial interests.

Parent-offspring interactions constitute the first contact of many newborns with their environment, priming community assembly of microbes through priority effects. Early exposure to microbes can have lasting influences on the assembly and functionality of the host's microbiota, leaving a life-long imprint on host health and disease. Studies of the role played by parental care in microbial acquisition have primarily focused on humans and hosts with agricultural relevance. Anuran vertebrates offer the opportunity to examine microbial community composition across life stages as a function of parental investment. In this study, we investigate vertical transmission of microbiota during parental care in a poison frog (Family Dendrobatidae ), where fathers transport their offspring piggyback-style from terrestrial clutches to aquatic nurseries. We found that substantial bacterial colonization of the embryo begins after hatching from the vitelline envelope, emphasizing its potential role as microbial barrier during early development. Using a laboratory cross-foster experiment, we demonstrated that poison frogs performing tadpole transport serve as a source of skin microbes for tadpoles on their back. To study how transport impacts the microbial skin communities of tadpoles in an ecologically relevant setting, we sampled frogs and tadpoles of sympatric species that do or do not exhibit tadpole transport in their natural habitat. We found more diverse microbial communities associated with tadpoles of transporting species compared to a non-transporting frog. However, we detected no difference in the degree of similarity between adult and tadpole skin microbiotas, based on whether the frog species exhibits transporting behavior or not. Using a field experiment, we confirmed that tadpole transport can result in the persistent colonization of tadpoles by isolated microbial taxa associated with the caregiver's skin, albeit often at low prevalence. This is the first study to describe vertical transmission of skin microbes in anuran amphibians, showing that offspring transport may serve as a mechanism for transmission of parental skin microbes. Overall, these findings provide a foundation for further research on how vertical transmission in this order impacts host-associated microbiota and physiology., Competing Interests: Declaration of Interests The authors declare no competing interests.

Motor function is a critical aspect of social behavior in a wide range of taxa. The transcription factor FoxP2 is well studied in the context of vocal communication in humans, mice, and songbirds, but its role in regulating social behavior in other vertebrate taxa is unclear. We examined the distribution and activity of FoxP2-positive neurons in tadpoles of the mimic poison frog ( Ranitomeya imitator ). In this species, tadpoles are reared in isolated plant nurseries and are aggressive to other tadpoles. Mothers provide unfertilized egg meals to tadpoles that perform a begging display by vigorously vibrating back and forth. We found that FoxP2 is widely distributed in the tadpole brain and parallels the brain distribution in mammals, birds, and fishes. We then tested the hypothesis that FoxP2-positive neurons would have differential activity levels in begging or aggression contexts compared to non-social controls. We found that FoxP2-positive neurons showed increased activation in the striatum and cerebellum during begging and in the nucleus accumbens during aggression. Overall, these findings lay a foundation for testing the hypothesis that FoxP2 has a generalizable role in social behavior beyond vocal communication across terrestrial vertebrates.

Background: The oral microbiome comprises distinct microbial communities that colonize diverse ecological niches across the oral cavity, the composition of which are influenced by nutrient and substrate availability, host genetics, diet, behavior, age, and other diverse host and environmental factors. Unlike other densely populated human-associated microbial ecosystems (e.g., gut, urogenital), the oral microbiome is regularly and directly exposed to the external environment and is therefore likely less stable over time. Cross sectional studies of the oral microbiome capture a glimpse of this temporal dynamism, yet a full appreciation of the relative stability, robusticity, and spatial structure of the oral environment is necessary to understand the role of microbial communities in promoting health or disease., Results: Here we investigate the spatial and temporal stability of the oral microbiome over three sampling time points in the context of HIV infection and exposure. Individual teeth were sampled from a cohort of 565 Nigerian children with varying levels of tooth decay severity (i.e., caries disease). We collected 1,960 supragingival plaque samples and characterized the oral microbiome using a metataxonomic approach targeting an approximately 478 bp region of the bacterial rpo C gene. We found that both infection and exposure to HIV have significant effects on the stability of the supragingival plaque microbiome at both the spatial and temporal scale. Specifically, we detect (1) significantly lower taxonomic turnover of the oral community among exposed and infected children compared to unexposed children, (2) we find that HIV infection homogenizes the oral community across the anterior and posterior dentition, and (3) that impaired immunity (i.e., low CD4 count) and low taxonomic turnover over time in children living with HIV is associated with higher frequency of cariogenic taxa including Streptococcus mutans ., Conclusions: Our results document substantial community fluctuations over time in children unexposed to HIV independent of oral health status. This suggests that the oral community, under typical conditions, rapidly adapts to environmental perturbations to maintain homeostasis and that long-term taxonomic rigidity is a signal of community dysfunction, potentially leading to a higher incidence of oral disease including caries., Competing Interests: Competing interests The authors declare that they have no competing interests Additional Declarations: No competing interests reported.

Background: Although numerous treatments exist for the management of rectovaginal fistula, none has demonstrated its superiority. The role of diverting stoma remains controversial. A few series include Martius flap in the armamentarium., Objective: Determine the role of gracilis muscle interposition and Martius flap in the surgical management of rectovaginal fistula., Design: Retrospective cohort study of a pooled prospectively maintained database from 3 centers., Patients: All consecutive eligible patients with rectovaginal fistula undergoing Martius flap and gracilis muscle interposition were included from 2001 to 2022., Main Outcome Measures: Success was defined by the absence of stoma and rectovaginal fistula., Results: Sixty-two patients were included with 55 Martius flap and 24 gracilis muscle interposition performed after failures of 164 initial procedures. Total length of stay was longer for gracilis muscle interposition by 2 days ( p = 0.01) without a significant difference in severe morbidity (20% vs 12%, p = 0.53). Twenty-seven percent of the Martius flap interpositions were performed without a stoma, which did not have an impact on overall morbidity ( p = 0.763). Per patient immediate success rates were not significantly different between groups (35% vs 31%, p > 0.99). The success of gracilis muscle interposition after the failure of the Martius flap was not significantly different from an initial gracilis muscle interposition ( p > 0.99). After simple perineal procedures, the immediate success rate rose to 49.4% (49% vs 50%, p > 0.99). After a median follow-up of 23 months, no significant difference was detected in success rate between the 2 procedures (69% vs 69%, p > 0.99). Smoking was the only negative predictive factor ( p = 0.02)., Limitations: By its retrospective nature, this study is limited in its comparison., Conclusions: This novel comparison between Martius flap and gracilis muscle interposition suggests that Martius flap presents several advantages, including shorter length of stay, similar morbidity, and similar success rate. Proximal diversion via a stoma for Martius flap does not appear mandatory. Gracilis muscle interposition could be reserved as a salvage procedure after Martius flap failure. See Video Abstract ., Fstula Rectovaginal Cul Es El Rol Del Colgajo De Martius Y La Interposicin Del Msculo Gracilis En La Estrategia Teraputica: ANTECEDENTES:Si bien existen numerosos tratamientos para el manejo de la fistula rectovaginal, ninguno ha demostrado su superioridad. El papel del estoma de derivación sigue siendo controvertido. Pocas series incluyen colgajo de Martius en el armamento.OBJETIVO:Determinar el rol de la interposición del músculo gracilis y del colgajo de Martius, en el manejo quirúrgico de la fístula rectovaginal.DISEÑO:Estudio de cohorte retrospectivo de una base de datos mantenida prospectivamente en 3 centros.AJUSTES/PACIENTES:Se incluyeron todos los pacientes elegibles consecutivos con fistula rectovaginal sometidos a colgajo de Martius y la interposición del músculo gracilis desde 2001 hasta 2022.RESULTADOS PRINCIPALES:El éxito se definió por la ausencia de estoma y fistula rectovaginal.RESULTADOS:Se incluyeron 62 pacientes con 55 colgajo de Martius y 24 con interposición del músculo gracilis realizados después de fracasos de 164 procedimientos iniciales. La duración total de la estancia hospitalaria fue dos días más larga para la interposición del músculo gracilis ( p = 0,01) sin una diferencia significativa en la morbilidad grave (20% frente a 12%, p = 0,53). El 27% de los colgajos de Martius se realizaron sin estoma, sin impacto en la morbilidad global ( p = 0,763). Las tasas de éxito inmediato por paciente no fueron significativamente diferentes entre los grupos (35% vs. 31%, p = 1,0). El éxito de la interposición del músculo gracilis después del fracaso del colgajo de Martius no fue significativamente diferente de una interposición del músculo gracilis inicial (p = 1,0). La tasa de éxito inmediato aumentó al 49,4% (49% frente a 50%, p = 1,0) después de procedimientos perineales simples. Después de una mediana de seguimiento de 23 meses, no se detectaron diferencias significativas en la tasa de éxito entre los dos procedimientos (69 % frente a 69 %, p = 1,0). El tabaquismo fue el único factor predictivo negativo ( p = 0,02).LIMITACIONES:Por su naturaleza retrospectiva, este estudio tiene limitaciones en su comparación.CONCLUSIÓN:Esta novedosa comparación entre colgajo de Martius y la interposición del músculo gracilis sugiere que el colgajo de Martius presenta varias ventajas, incluida una estancia prolongada más corta, una morbilidad similar y un éxito. La derivación proximal a través de un estoma para el colgajo de Martius no parece obligatoria. La interposición del músculo gracilis podría reservarse como procedimiento de rescate después de una falla de colgajo de Martius. (Traducción-Dr. Aurian Garcia Gonzalez )., (Copyright © The ASCRS 2024.)

More than a century ago, Charles Darwin hypothesized that the empathy-like phenotype is a phylogenetically widespread phenomenon. This idea remains contentious, due to the challenges of empirically examining emotions, and few investigations among non-mammalian vertebrates. We provide support for Darwin's hypothesis by discovering partial evidence for the most ancestral form of empathy, emotional contagion (i.e. matching another individual's emotional state), in the pair bonding mimetic poison frog, Ranitomeya imitator . We found that male corticosterone, a physiological biomarker of stress, positively correlates with female partners in experimental and semi-natural conditions. This does not appear to coincide with behavioural state-matching. However, it is specific to female partners relative to familiar female non-partners, and is independent of effects that commonly confound studies on emotional contagion. Furthermore, this physiological state-matching is irrespective of partnership longevity or lifetime reproductive output. These results physiologically indicate socially selective emotional contagion in a monogamous amphibian, and paradigms that elicit coinciding neural and behavioural indicators and morphogenic co-variation are needed for further corroboration. Further studies on ancestral forms of empathy in non-mammalian vertebrates are warranted., Competing Interests: We declare we have no competing interests., (© 2024 The Authors.)

The behavioral, sensory, and neural bases of vertebrate navigation are primarily described in mammals and birds. However, we know much less about navigational abilities and mechanisms of vertebrates that move on smaller scales, such as amphibians. To address this knowledge gap, we conducted an extensive field study on navigation in the cane toad, Rhinella marina . First, we performed a translocation experiment to describe how invasive toads in Hawai'i navigate home following displacements of up to one kilometer. Next, we tested the effect of olfactory and magnetosensory manipulations on homing, as these senses are most commonly associated with amphibian navigation. We found that neither ablation alone prevents homing, suggesting that toad navigation is multimodal. Finally, we tested the hypothesis that the medial pallium, the amphibian homolog to the hippocampus, is involved in homing. By comparing neural activity across homing and non-homing toads, we found evidence supporting the involvement of the medial pallium, lateral pallium, and septum in navigation, suggesting a conservation of neural structures supporting navigation across vertebrates. Our study lays the foundation to understand the behavioral, sensory, and neural bases of navigation in amphibians and to further characterize the evolution of behavior and neural structures in vertebrates., Competing Interests: Competing interests The authors declare no competing or financial interests.

Arginine catabolism by the bacterial arginine deiminase system (ADS) has anticariogenic properties through the production of ammonia, which modulates the pH of the oral environment. Given the potential protective capacity of the ADS pathway, the exploitation of ADS-competent oral microbes through pre- or probiotic applications is a promising therapeutic target to prevent tooth decay. To date, most investigations of the ADS in the oral cavity and its relation to caries have focused on indirect measures of activity or on specific bacterial groups, yet the pervasiveness and rate of expression of the ADS operon in diverse mixed microbial communities in oral health and disease remain an open question. Here, we use a multivariate approach, combining ultra-deep metatranscriptomic sequencing with paired metataxonomic and in vitro citrulline quantification to characterize the microbial community and ADS operon expression in healthy and late-stage cavitated teeth. While ADS activity is higher in healthy teeth, we identify multiple bacterial lineages with upregulated ADS activity on cavitated teeth that are distinct from those found on healthy teeth using both reference-based mapping and de novo assembly methods. Our dual metataxonomic and metatranscriptomic approach demonstrates the importance of species abundance for gene expression data interpretation and that patterns of differential expression can be skewed by low-abundance groups. Finally, we identify several potential candidate probiotic bacterial lineages within species that may be useful therapeutic targets for the prevention of tooth decay and propose that the development of a strain-specific, mixed-microbial probiotic may be a beneficial approach given the heterogeneity of taxa identified here across health groups., Importance: Tooth decay is the most common preventable chronic disease, affecting more than two billion people globally. The development of caries on teeth is primarily a consequence of acid production by cariogenic bacteria that inhabit the plaque microbiome. Other bacterial strains in the oral cavity may suppress or prevent tooth decay by producing ammonia as a byproduct of the arginine deiminase metabolic pathway, increasing the pH of the plaque biofilm. While the benefits of arginine metabolism on oral health have been extensively documented in specific bacterial groups, the prevalence and consistency of arginine deiminase system (ADS) activity among oral bacteria in a community context remain an open question. In the current study, we use a multi-omics approach to document the pervasiveness of the expression of the ADS operon in both health and disease to better understand the conditions in which ADS activity may prevent tooth decay., Competing Interests: The authors declare no conflict of interest.

Aim: Neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer facilitates tumour downstaging and complete pathological response (pCR). The goal of neoadjuvant systemic chemotherapy (total neoadjuvant chemotherapy, TNT) is to further improve local and systemic control. While some patients forgo surgery, total mesorectal excision (TME) remains the standard of care. While TNT appears to be noninferior to nCRT with respect to short-term oncological outcomes few data exist on perioperative outcomes. Perioperative morbidity including anastomotic leaks is associated with a negative effect on oncological outcomes, probably due to a delay in proceeding to adjuvant therapy. Thus, we aimed to compare conversion rates, rates of sphincter-preserving surgery and anastomosis formation rates in patients undergoing rectal resection after either TNT or standard nCRT., Methods: An institutional colorectal oncology database was searched from January 2018 to July 2023. Inclusion criteria comprised patients with histologically confirmed rectal cancer who had undergone neoadjuvant therapy and TME. Exclusion criteria comprised patients with a noncolorectal primary, those operated on emergently or who had local excision only. Outcomes evaluated included rates of conversion to open, sphincter-preserving surgery, anastomosis formation and anastomotic leak., Results: A total of 119 patients were eligible for inclusion (60 with standard nCRT, 59 with TNT). There were no differences in rates of sphincter preservation or primary anastomosis formation between the groups. However, a significant increase in conversion to open (p = 0.03) and anastomotic leak (p = 0.03) was observed in the TNT cohort., Conclusion: In this series TNT appears to be associated with higher rates of conversion to open surgery and higher anastomotic leak rates. While larger studies will be required to confirm these findings, these factors should be considered alongside oncological benefits when selecting treatment strategies., (© 2024 The Association of Coloproctology of Great Britain and Ireland.)

Ant behavior relies on a collection of natural products, from following trail pheromones during foraging to warding off potential predators. How nervous systems sense these compounds to initiate a behavioral response remains unclear. Here, we used Caenorhabditis elegans chemotaxis assays to investigate how ant compounds are detected by heterospecific nervous systems. We found that C. elegans avoid extracts of the pavement ant ( Tetramorium immigrans ) and either osm-9 or tax-4 ion channels are required for this response. These experiments were conducted in an undergraduate laboratory course, demonstrating that new insights into interspecies interactions can be generated through genuine research experiences in a classroom setting., Competing Interests: The authors declare that there are no conflicts of interest present., (Copyright: © 2024 by the authors.)

Introduction: Although effective, conventional excisional haemorrhoidectomy (CEH) is associated with significant postoperative pain. Novel techniques such as transanal haemorrhoidal dearterialization (THD) are suggested to reduce pain but may result in higher recurrence rates. We aimed to compare short- and long-term outcomes of CEH and THD in the present meta-analysis., Methods: A PRISMA-compliant meta-analysis was performed, searching PubMed, Embase, and CENTRAL databases for randomised controlled trials (RCTs) from 1995 to December 2022. The primary objective was recurrence. Secondary objectives included complication rates, length of stay (LOS), operative time, and time to return to baseline. Random-effects models were used to calculate pooled effect size estimates. Subgroup analysis was also performed., Results: A total of 6 RCTs encompassing 465 patients were captured. There were 142 (59%) males in the CEH group and 129 (54%) in the THD group. On random-effects analysis, THD had a higher recurrence rate (odds ratio = 2.76, 95% confidence interval [CI] = 1.03-7.38, p = 0.04) albeit a shorter return to baseline compared to CEH (mean difference = -14.05 days, 95% CI = -20.38 to -7.72, p < 0.0001). There were no differences in bleeding (p = 0.12), urinary retention (p = 0.97), incontinence (p = 0.41), anal stenosis (p = 0.19), thrombosed residual haemorrhoids (p = 0.16), operating time (p = 0.19), or LOS (p = 0.22). Results remained similar on subgroup analysis., Conclusions: CEH is associated with lower recurrence but similar complication rates to THD, although patients take longer to return to baseline function postoperatively., (© 2024 S. Karger AG, Basel.)

Alkaloids are important bioactive molecules throughout the natural world, and in many animals they serve as a source of chemical defense against predation. Dendrobatid poison frogs bioaccumulate alkaloids from their diet to make themselves toxic or unpalatable to predators. Despite the proposed roles of plasma proteins as mediators of alkaloid trafficking and bioavailability, the responsible proteins have not been identified. We use chemical approaches to show that a ~50 kDa plasma protein is the principal alkaloid-binding molecule in blood of poison frogs. Proteomic and biochemical studies establish this plasma protein to be a liver-derived alkaloid-binding globulin (ABG) that is a member of the serine-protease inhibitor (serpin) family. In addition to alkaloid-binding activity, ABG sequesters and regulates the bioavailability of 'free' plasma alkaloids in vitro. Unexpectedly, ABG is not related to saxiphilin, albumin, or other known vitamin carriers, but instead exhibits sequence and structural homology to mammalian hormone carriers and amphibian biliverdin-binding proteins. ABG represents a new small molecule binding functionality in serpin proteins, a novel mechanism of plasma alkaloid transport in poison frogs, and more broadly points toward serpins acting as tunable scaffolds for small molecule binding and transport across different organisms., Competing Interests: AA, MF, MM, AR, ET, JT, HS, LC, JL, LO No competing interests declared, (© 2023, Alvarez-Buylla et al.)

Importance: Globally, caries is among the most frequent chronic childhood disease, and the fungal component of the microbial community responsible is poorly studied despite evidence that fungi contribute to increased acid production exacerbating enamel demineralization. HIV infection is another global health crisis. Perinatal HIV exposure with infection are caries risk factors; however, the caries experience in the context of perinatal HIV exposure without infection is less clear. Using high-throughput amplicon sequencing, we find taxonomic differences that become pronounced during late-stage caries. Notably, we show a stronger correlation with health-associated taxa for HIV-exposed-but-uninfected children when compared to unexposed and uninfected children. This aligns with a lower incidence of caries in primary teeth at age 6 or less for exposed yet uninfected children. Ultimately, these findings could contribute to improved risk assessment, intervention, and prevention strategies such as biofilm disruption and the informed design of pro-, pre-, and synbiotic oral therapies., Competing Interests: The authors declare no conflict of interest.

Amphibians are ideal for studying visual system evolution because their biphasic (aquatic and terrestrial) life history and ecological diversity expose them to a broad range of visual conditions. Here, we evaluate signatures of selection on visual opsin genes across Neotropical anurans and focus on three diurnal clades that are well-known for the concurrence of conspicuous colors and chemical defense (i.e., aposematism): poison frogs (Dendrobatidae), Harlequin toads (Bufonidae: Atelopus), and pumpkin toadlets (Brachycephalidae: Brachycephalus). We found evidence of positive selection on 44 amino acid sites in LWS, SWS1, SWS2, and RH1 opsin genes, of which one in LWS and two in RH1 have been previously identified as spectral tuning sites in other vertebrates. Given that anurans have mostly nocturnal habits, the patterns of selection revealed new sites that might be important in spectral tuning for frogs, potentially for adaptation to diurnal habits and for color-based intraspecific communication. Furthermore, we provide evidence that SWS2, normally expressed in rod cells in frogs and some salamanders, has likely been lost in the ancestor of Dendrobatidae, suggesting that under low-light levels, dendrobatids have inferior wavelength discrimination compared to other frogs. This loss might follow the origin of diurnal activity in dendrobatids and could have implications for their behavior. Our analyses show that assessments of opsin diversification in across taxa could expand our understanding of the role of sensory system evolution in ecological adaptation., Competing Interests: Conflict of interest: This publication is based in part on work by D.C.C. while serving at the National Science Foundation. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation or United States government., (© The Author(s) 2023. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

Children living with HIV have a higher prevalence of oral diseases, including caries, but the mechanisms underlying this higher prevalence are not well understood. Here, we test the hypothesis that HIV infection is associated with a more cariogenic oral microbiome, characterized by an increase in bacteria involved in the pathogenesis of caries. We present data generated from supragingival plaques collected from 484 children representing three exposure groups: (i) children living with HIV (HI), (ii) children who were perinatally exposed but uninfected (HEU), and (iii) unexposed and therefore uninfected children (HUU). We found that the microbiome of HI children is distinct from those of HEU and HUU children and that this distinction is more pronounced in diseased teeth than healthy teeth, suggesting that the impact of HIV is more severe as caries progresses. Moreover, we report both an increase in bacterial diversity and a decrease in community similarity in our older HI cohort compared to our younger HI cohort, which may in part be a prolonged effect of HIV and/or its treatment. Finally, while Streptococcus mutans is often a dominant species in late-stage caries, it tended to be found at lower frequency in our HI cohort than in other groups. Our results highlight the taxonomic diversity of the supragingival plaque microbiome and suggest that broad and increasingly individualistic ecological shifts are responsible for the pathogenesis of caries in children living with HIV, coupled with a diverse and possibly severe impact on known cariogenic taxa that potentially exacerbates caries. IMPORTANCE Since its recognition as a global epidemic in the early 1980s, approximately 84.2 million people have been diagnosed with HIV and 40.1 million people have died from AIDS-related illnesses. The development and increased global availability of antiretroviral treatment (ART) regimens have dramatically reduced the mortality rate of HIV and AIDS, yet approximately 1.5 million new infections were reported in 2021, 51% of which are in sub-Saharan Africa. People living with HIV have a higher prevalence of caries and other chronic oral diseases, the mechanisms of which are not well understood. Here, we used a novel genetic approach to characterize the supragingival plaque microbiome of children living with HIV and compared it to the microbiomes of uninfected and perinatally exposed children to better understand the role of oral bacteria in the etiology of tooth decay in the context of HIV exposure and infection., Competing Interests: The authors declare no conflict of interest.

Background: Acute appendicitis represents the leading cause of acute gastrointestinal disorders, but only a small series regarding ambulatory appendectomies are available. The aim of this study was to report the results of ambulatory (day-case) appendectomy for acute appendicitis in a large consecutive cohort and to improve selection criteria in order to extend the indications., Methods: All appendectomy procedures for acute appendicitis (March 2013 to June 2020) were included retrospectively. Criteria to select patients eligible for ambulatory appendectomy were based on our clinico-radiological St-Antoine's score ≥4., Results: In total, 1,730 consecutive patients had an appendectomy for acute appendicitis: 1,279 (74%) in conventional settings and 451 (26%) in ambulatory settings. In the conventional group, 360 (28%) patients had surgery deferred to the next morning, whereas in the ambulatory group, 309 patients (70%) were readmitted the next morning (P < .0001). In the ambulatory group, 376 (83%) patients satisfied the criteria (score ≥4), and 90.9% were discharged on postoperative day 0. Rates of unplanned consultation and readmission were not significantly different (5.1% vs 6.6% P = .243). Multivariate analysis of the entire cohort confirmed absence of radiological perforation as highly predictive of early discharge (odds ratio = 6.073). In our cohort, these patients had an early discharge rate of 86.4% compared to 90.2% in those with a St-Antoine's score ≥4. Considering only radiological evidence of perforation as a selection criterion for ambulatory appendectomy, 581 more patients would be eligible for ambulatory surgery (+60%)., Conclusion: Ambulatory surgery for acute appendicitis based on St-Antoine's score is safe. We propose to extend the indication for ambulatory management to all patients without radiological evidence of perforation., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: Report the rate of successful pregnancy in a national cohort of women with either an ileal pouch anal (IPAA) or ileorectal (IRA) anastomosis constructed after colectomy for inflammatory bowel disease (IBD) or polyposis., Background: Fertility after IPAA is probably impaired. All available data are corroborated by only small sample size studies. It is not known whether construction of IPAA versus IRA influences the odds of subsequently achieving a successful pregnancy, especially with increased utilization of the laparoscopic approach., Methods: All women (age: 12-45 y) undergoing IRA or IPAA in France for polyposis or IBD, between 2010-2020, were included. A control population was defined as women aged from 12 to 45 years undergoing laparoscopic appendicectomy during the same period. The odds of successful pregnancy were studied using an adjusted survival analysis., Results: A total of 1491 women (IPAA=872, 58%; IRA=619, 42%) were included. A total of 220 deliveries (15%) occurred during the follow-up period of 71 months (39-100). After adjustment, the odds of successful pregnancy was not significantly associated with type of anastomosis (after IPAA: Hazard Ratio [HR]=0.79, 95% confidence interval=0.56-1.11, P =0.17). The laparoscopic approach increased the odds of achieving successful pregnancy (HR=1.79, 95% confidence interval=1.20-2.63, P =0.004). IRA and IPAA significantly impacted fertility when compared with the control population ( P <0.001)., Conclusions: In this large cohort study, total colectomy for polyposis or IBD was associated with reduced fertility compared with the general population. No difference in odds of achieving successful pregnancy was found between IRA and IPAA after adjustment. This analysis suggests laparoscopic surgery may be associated with greater likelihood of pregnancy., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Many ant species are equipped with chemical defenses, although how these compounds impact nervous system function is unclear. Here, we examined the utility of Caenorhabditis elegans chemotaxis assays for investigating how ant chemical defense compounds are detected by heterospecific nervous systems. We found that C. elegans respond to extracts from the invasive Argentine Ant ( Linepithema humile ) and the osm-9 ion channel is required for this response. Divergent strains varied in their response to L. humile extracts, suggesting genetic variation underlying chemotactic responses. These experiments were conducted by an undergraduate laboratory course, highlighting how C. elegans chemotaxis assays in a classroom setting can provide genuine research experiences and reveal new insights into interspecies interactions., (Copyright: © 2023 by the authors.)

This autoethnography examines my experience of the diagnosis and treatment of anorexia nervosa. Drawing on memory and personal and medical documents relating to inpatient admissions in an adult specialist eating disorder unit, I narrate and analyse my experience in terms of my relationship to the diagnosis of anorexia and the constructions of it I encountered. I show how I came to value an identity based on anorexia and how I learned ways of 'doing' the diagnosis in treatment. This involved me valuing medical markers of illness, including signs of poor health, which became crucial to how I performed my diagnosis and retained the diagnostically-informed sense of self that I valued. I suggest that, ultimately, these diagnostic-dynamics, alongside other effects of long-term inpatient treatment such as detachment from 'normal life', prolonged my struggles with self-starvation. The insights from this autoethnography shed light on potential iatrogenic impacts of diagnosis and treatment for anorexia.

Tadpoles display preferences for different environments but the sensory modalities that govern these choices are not well understood. Here, we examined light preferences and associated sensory mechanisms of albino and wild-type Xenopus laevis tadpoles. We found that albino tadpoles spent more time in darker environments compared to the wild type, although they showed no differences in overall activity. This preference persisted when the tadpoles had their optic nerve severed or pineal glands removed, suggesting these sensory systems alone are not necessary for phototaxis. These experiments were conducted by an undergraduate laboratory course, highlighting how X. laevis tadpole behavior assays in a classroom setting can reveal new insights into animal behavior., (Copyright: © 2023 by the authors.)

American bullfrog ( Rana castesbeiana ) saxiphilin ( Rc Sxph) is a high-affinity "toxin sponge" protein thought to prevent intoxication by saxitoxin (STX), a lethal bis-guanidinium neurotoxin that causes paralytic shellfish poisoning (PSP) by blocking voltage-gated sodium channels (Na V s). How specific Rc Sxph interactions contribute to STX binding has not been defined and whether other organisms have similar proteins is unclear. Here, we use mutagenesis, ligand binding, and structural studies to define the energetic basis of Sxph:STX recognition. The resultant STX "recognition code" enabled engineering of Rc Sxph to improve its ability to rescue Na V s from STX and facilitated discovery of 10 new frog and toad Sxphs. Definition of the STX binding code and Sxph family expansion among diverse anurans separated by ∼140 My of evolution provides a molecular basis for understanding the roles of toxin sponge proteins in toxin resistance and for developing novel proteins to sense or neutralize STX and related PSP toxins.

Poison frogs are well-known for their fascinating ability to store alkaloids in their skin as chemical defense against predators. Chemical methods used to study these alkaloids are limited by requirements for euthanasia or stress during sampling. Here, we demonstrate sensitive and biocompatible alkaloid detection and monitoring in vivo using the MasSpec Pen, a handheld, noninvasive chemical detection device coupled to a mass spectrometer. The MasSpec Pen allowed rapid (<15 s), gentle, and consecutive molecular analysis without harm or undue stress to the animals. Through a month-long alkaloid-feeding study with the dyeing poison frog, we observed temporal dynamics of chemical sequestration in vivo by comparing frogs fed the alkaloid decahydroquinoline (DHQ) to vehicle-fed frogs. We also demonstrate the feasibility of the MasSpec Pen for the untargeted detection of rich alkaloid profiles from skin extracts of the Diablito poison frog , collected from two distinct geographical populations in Ecuador. The results obtained in this study demonstrate the utility of the MasSpec Pen for direct, rapid, and biocompatible analysis of poison frog alkaloids., Competing Interests: The authors declare the following competing financial interest(s): L.S.E. is an inventor in US Patent No. 10,643,832 and/or in other patent applications related to the MasSpec Pen Technology licensed by the University of Texas to MS Pen Technologies, Inc. L.S.E. is a shareholder in MS Pen Technologies, Inc. and serves as chief scientific officer for MS Pen Technologies, Inc. All other authors declare no competing interests., (© 2022 The Authors. Published by American Chemical Society.)

Infants learn and develop within an ecological context that includes family, peers, and broader built and social environments. This development relies on proximal processes-reciprocal interactions between infants and the people and environments around them that help them understand their world. Most research examining predictors of proximal processes like parent-child interaction and parenting has focused on elements within the home and family. However, factors like the neighborhood built environment may also exhibit an influence, and may be particularly critical in infancy, as socioeconomic disparities in cognition and language emerge early in life. Moreover, influence from the built environment could independently exacerbate these disparities, as research indicates that neighborhood impacts may be especially relevant for families living in neighborhoods that have experienced disinvestment and therefore have been under-resourced. The current study examines these questions by determining the association of neighborhood vacancy rate and observed physical disorder-indicators of poverty, residential stability, and long-term structural discrimination-with parental cognitive stimulation among predominantly Black/African-American families in Flint, Michigan. Flint is particularly salient for this study because vacancy rates and disinvestment vary widely across the city, driven by its long-time status as a city struggling economically. Regression analyses controlling for caregiver education, mental health, and social support indicated that vacancy rate and physical disorder negatively predicted parental cognitive stimulation. Moreover, there were significant interactions between the built environment and social support, indicating that, particularly for parent-child shared reading, vacancy rate and physical disorder predicted reduced shared reading only when parents had limited social support. These results have important implications for public policy around vacant property demolition and neighborhood reinvestment programs, as they indicate that the neighborhood built environment is associated with parenting behaviors that have important impacts on infants' learning and development., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Canfield, O’Connell, Sadler, Gutierrez, Williams and Mendelsohn.)

Background: A better understanding of pathological features and oncological survival in ypT0 rectal cancer after neoadjuvant chemoradiotherapy is required to improve patient selection criteria for rectal-preserving approach by local excision. Our aim was to define risk of lymph node metastasis and oncological outcomes in ypT0 rectal cancer after chemoradiotherapy and total mesorectal excision., Methods: All consecutive patients who underwent total mesorectal excision for a nonmetastatic rectal adenocarcinoma classified ypT0 after neoadjuvant chemoradiotherapy, with or without locoregional lymph node involvement (ypN+ or ypN-), in 14 French academic centers between 2002 and 2015 were included. Data were collected retrospectively. Overall and disease-free survival were explored., Results: Among the 383 ypT0 patients, 6% were ypN+ (23/283). Before chemoradiotherapy, 86% (327/380) were staged cT3-T4 and 41% (156/378) were staged cN+. The risk of ypN+ did not differ between cT3-T4 and cT1-T2 patients (P = .345) or between cN+ and cN- patients (P = .384). After a median follow-up of 61.1 months, we observed 95% confidence interval (92%-97%) of 5-year overall survival and 93% confidence interval (91%-96%) of 5-year disease-free survival. In Cox multivariate analysis, overall survival was altered by intra-abdominal septic complications (hazard ratio = 2.53, confidence interval [1.11-5.78], P = .028). Regarding disease-free survival, ypN+ status and administration of adjuvant chemotherapy were associated with a reduced disease-free survival (P = .001 for both). cT3/T4 staging and cN+ staging did not modify overall survival (P = .332 and P = .450) nor disease-free survival (P = .862 and P = .124)., Conclusion: The risk of lymph node metastasis and the oncological survival do not depend on the initial cT or cN staging in cases of ypT0 complete rectal tumor regression., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Although the use of robotic-assisted surgery is now mainstream for procedures such as robotic prostatectomy and hysterectomy, its role in general surgery is less well established. Access to training in robotics for general surgery trainees in the Republic of Ireland is variable. Further, there are no data on specific attitudes of Irish trainees toward the role of robotics. We aimed to establish attitudes of Irish general surgery trainees toward the perceived utility of robotic surgery as well as access and satisfaction with training., Methods: A survey was disseminated to trainees in the Republic of Ireland enrolled in a General Surgery training scheme via email and social media. Data collected included stage of training, intended subspecialty, interest in developing robotic skills, previous exposure to robotic surgery, satisfaction with current access to robotic training, and opinion on formally incorporating training in robotics into the general surgery curriculum., Results: The response rate was 53.8%. Of these, 83% reported interest in training in robotics and 66% anticipated using the technology regularly in consultant practice. Previous exposure to robotic-assisted surgery was significantly predictive of interest in developing the skillset (P = .014). More than 71% of trainees reported that they were not satisfied with access to robotic training. Of those satisfied with access, 40% felt there was a role for incorporating robotic training into the curriculum compared to 68% of those dissatisfied., Conclusion: Irish general surgery trainees perceive robotic-assisted surgery to be highly relevant to their future practice. There is an unmet need to provide additional training in the skillset., (© 2022 The Authors.)

Background: This study seeks to understand better the mechanisms underlying the increased risk of caries in HIV-infected school-aged Nigerian children by examining the relationship between the plaque microbiome and perinatal HIV infection and exposure. We also seek to investigate how perinatal HIV infection and exposure impact tooth-specific microbiomes' role on caries disease progression., Methods: The participants in this study were children aged 4 to 11 years recruited from the University of Benin Teaching Hospital (UBTH), Nigeria, between May to November 2019. Overall, 568 children were enrolled in three groups: 189 HIV-infected (HI), 189 HIV-exposed but uninfected (HEU) and 190 HIV-unexposed and uninfected (HUU) as controls at visit 1 with a 2.99% and 4.90% attrition rate at visit 2 and visit 3 respectively. Data were obtained with standardized questionnaires. Blood samples were collected for HIV, HBV and HCV screening; CD4, CD8 and full blood count analysis; and plasma samples stored for future investigations; oral samples including saliva, buccal swabs, oropharyngeal swab, tongue swab, dental plaque were collected aseptically from participants at different study visits., Conclusions: Results from the study will provide critical information on how HIV exposure, infection, and treatment, influence the oral microbiome and caries susceptibility in children. By determining the effect on community taxonomic structure and gene expression of dental microbiomes, we will elucidate mechanisms that potentially create a predisposition for developing dental caries. As future plans, the relationship between respiratory tract infections, immune and inflammatory markers with dental caries in perinatal HIV infection and exposure will be investigated., (© 2021. The Author(s).)

Introduction: Tools for improving operative performance for surgical trainees are increasingly desirable, particularly in the context of EWTD and 'run-through' training programmes. In addition, positive direct trainer feedback to trainees can improve skill acquisition and motivation, whilst negative feedback may have the opposite effect. 1 We aimed to examine the impact of targeted trainer feedback based on video analysis on trainee confidence and objective operative performance in laparoscopic cholecystectomy., Methods: Selected procedures designated as training cases were recorded. These were assessed by the trainers using the Independence-Scaled Procedural Assessment Score for laparoscopic cholecystectomy. Targeted feedback based on video review of selected procedures was then delivered by the trainers to the trainees. Trainees completed a self-reported questionnaire based on their response to this feedback. Subsequent to the feedback intervention, further training procedures were recorded and assessed., Results: A total of 6 trainees and 4 trainers participated in the study. For the pre-intervention assessment 15 cases were recorded, with a further 13 for the post-intervention assessment (total n = 28). The overall scores for the procedures performed post video feedback were improved, with a trend towards statistical significance (p = 0.08). However, there was a statistically significant improvement in the scores for performance of the triangle of Calot dissection after the feedback intervention (p = 0.009). The response rate to the questionnaire was 100%, with all trainees agreeing that they felt more confident and competent after the feedback intervention., Conclusion: Targeted feedback to trainees based on post-procedure video review improves trainee confidence and may also improve performance. ACGME Core Competencies; Patient Care and Procedural Skills; Practice Based Learning and Improvement., Competing Interests: Declaration of competing interest None declared., (Copyright © 2020 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.)

Many poisonous organisms carry small-molecule toxins that alter voltage-gated sodium channel (NaV) function. Among these, batrachotoxin (BTX) from Pitohui poison birds and Phyllobates poison frogs stands out because of its lethality and unusual effects on NaV function. How these toxin-bearing organisms avoid autointoxication remains poorly understood. In poison frogs, a NaV DIVS6 pore-forming helix N-to-T mutation has been proposed as the BTX resistance mechanism. Here, we show that this variant is absent from Pitohui and poison frog NaVs, incurs a strong cost compromising channel function, and fails to produce BTX-resistant channels in poison frog NaVs. We also show that captivity-raised poison frogs are resistant to two NaV-directed toxins, BTX and saxitoxin (STX), even though they bear NaVs sensitive to both. Moreover, we demonstrate that the amphibian STX "toxin sponge" protein saxiphilin is able to protect and rescue NaVs from block by STX. Taken together, our data contradict the hypothesis that BTX autoresistance is rooted in the DIVS6 N→T mutation, challenge the idea that ion channel mutations are a primary driver of toxin resistance, and suggest the possibility that toxin sequestration mechanisms may be key for protecting poisonous species from the action of small-molecule toxins., (© 2021 Abderemane-Ali et al.)

Background: The mucus gel layer (MGL) lining the colon is integral to exclusion of bacteria and maintaining intestinal homeostasis in health and disease. Some MGL defects allowing bacteria to directly contact the colonic surface are commonly observed in ulcerative colitis (UC). The major macromolecular component of the colonic MGL is the secreted gel-forming mucin MUC2, whose expression is essential for homeostasis in health. In UC, another gel-forming mucin, MUC5AC, is induced. In mice, Muc5ac is protective during intestinal helminth infection. Here we tested the expression and functional role of MUC5AC/Muc5ac in UC biopsies and murine colitis., Methods: We measured MUC5AC/Muc5ac expression in UC biopsies and in dextran sulfate sodium (DSS) colitis. We performed DSS colitis in mice deficient in Muc5ac (Muc5ac-/-) to model the potential functional role of Muc5ac in colitis. To assess MGL integrity, we quantified bacterial-epithelial interaction and translocation to mesenteric lymph nodes. Antibiotic treatment and 16S rRNA gene sequencing were performed to directly investigate the role of bacteria in murine colitis., Results: Colonic MUC5AC/Muc5ac mRNA expression increased significantly in active UC and murine colitis. Muc5ac-/- mice experienced worsened injury and inflammation in DSS colitis compared with control mice. This result was associated with increased bacterial-epithelial contact and translocation to the mesenteric lymph nodes. However, no change in microbial abundance or community composition was noted. Antibiotic treatment normalized colitis severity in Muc5ac-/- mice to that of antibiotic-treated control mice., Conclusions: MUC5AC/Muc5ac induction in the acutely inflamed colon controls injury by reducing bacterial breach of the MGL., (© 2020 Crohn’s & Colitis Foundation. Published by Oxford University Press on behalf of Crohn’s & Colitis Foundation.)

Affiliative behaviours have evolved many times across animals. Research on the mechanisms underlying affiliative behaviour demonstrates remarkable convergence across species spanning wide evolutionary distances. Shared mechanisms have been identified with genomic approaches analysing genetic variants and gene expression differences as well as neuroendocrine and molecular approaches exploring the role of hormones and signalling molecules. We review the genomic and neural basis of pair bonding and parental care across diverse taxa to shed light on mechanistic patterns that underpin the convergent evolution of affiliative behaviour. We emphasize that mechanisms underlying convergence in complex phenotypes like affiliation should be evaluated on a continuum, where signatures of convergence may vary across levels of biological organization. In particular, additional comparative studies within and across major vertebrate lineages will be essential in resolving when and why shared neural substrates are repeatedly targeted in the independent evolution of affiliation, and how similar mechanisms are evolutionarily tuned to give rise to species-specific variations in behaviour. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.

Parental care is critical for offspring survival in many species. However, parental behaviors have been lost in roughly 1% of avian species known as the obligate brood parasites. To shed light on molecular and neurobiological mechanisms mediating brood parasitic behavior, we compared brain gene expression patterns between two brood parasitic species and one closely related non-parasitic Icterid (blackbird) species. Our analyses focused on gene expression changes specifically in the preoptic area (POA), a brain region known to play a critical role in parental behavior across vertebrates. Using comparative transcriptomic approaches, we identified gene expression patterns associated with brood parasitism. We evaluated three non-mutually exclusive alternatives for the evolution of brood parasitism: (1) retention of juvenile-like (neotenic) gene expression, (2) reduced expression of maternal care-related genes in the POA, and/or (3) increased expression of genes inhibiting maternal care. We find evidence for neotenic expression patterns in both species of parasitic cowbirds as compared to maternal, non-parasites. In addition, we observed differential expression in a number of genes with previously established roles in mediating maternal care. Together, these results provide the first insight into transcriptomic and genetic mechanisms underlying the loss of maternal behavior in avian brood parasites., (Copyright © 2019 Lynch et al.)

Background: Similar to natural rivers, manmade inlets connect inland runoff to the ocean. Port Everglades Inlet (PEI) is a busy cargo and cruise ship port in South Florida, which can act as a source of pollution to surrounding beaches and offshore coral reefs. Understanding the composition and fluctuations of bacterioplankton communities ("microbiomes") in major port inlets is important due to potential impacts on surrounding environments. We hypothesize seasonal microbial fluctuations, which were profiled by high throughput 16S rRNA amplicon sequencing and analysis., Methods & Results: Surface water samples were collected every week for one year. A total of four samples per month, two from each sampling location, were used for statistical analysis creating a high sampling frequency and finer sampling scale than previous inlet microbiome studies. We observed significant differences in community alpha diversity between months and seasons. Analysis of composition of microbiomes (ANCOM) tests were run in QIIME 2 at genus level taxonomic classification to determine which genera were differentially abundant between seasons and months. Beta diversity results yielded significant differences in PEI community composition in regard to month, season, water temperature, and salinity. Analysis of potentially pathogenic genera showed presence of Staphylococcus and Streptococcus . However, statistical analysis indicated that these organisms were not present in significantly high abundances throughout the year or between seasons., Discussion: Significant differences in alpha diversity were observed when comparing microbial communities with respect to time. This observation stems from the high community evenness and low community richness in August. This indicates that only a few organisms dominated the community during this month. August had lower than average rainfall levels for a wet season, which may have contributed to less runoff, and fewer bacterial groups introduced into the port surface waters. Bacterioplankton beta diversity differed significantly by month, season, water temperature, and salinity. The 2013-2014 dry season (October-April), was warmer and wetter than historical averages. This may have driven significant differences in beta diversity. Increased nitrogen and phosphorous concentrations were observed in these dry season months, possibly creating favorable bacterial growth conditions. Potentially pathogenic genera were present in the PEI. However their relatively low, non-significant abundance levels highlight their relatively low risk for public health concerns. This study represents the first to sample a large port at this sampling scale and sequencing depth. These data can help establish the inlet microbial community baseline and supplement the vital monitoring of local marine and recreational environments, all the more poignant in context of local reef disease outbreaks and worldwide coral reef collapse in wake of a harsh 2014-16 El Niño event., Competing Interests: The authors declare there are no competing interests.

Introduction: Synovial chrondomatosis is a rare disorder characterised by the development of hyaline cartilage from the synovial membrane. Large isolated lesions in the Hoffa's fat pad are an uncommon entity., Presentation of Case: A 33 year old gentleman presented complaining of progressive knee pain associated with an enlarging lesion on the anterior aspect of the right knee, with associated locking and giving way. Examination revealed a firm 4×5cm lesion adjacent to the patellar tendon. Subsequent CT and MRI demonstrated a lesion in the inferior aspect of Hoffa's fat pad, with a second lesion adjacent to the proximal tibiofibular joint, in addition to advanced degenerative changes and a meniscal tear. He proceeded to excisional biopsy. Histological analysis was consistent with a solitary synovial osteochondroma. There were no atypical features suggestive of malignancy., Discussion: Synovial chondromatosis is a rare disorder affecting the synovial joints. The underlying pathophysiology is thought to be metaplastic change of the synovium to hyaline cartilaginous tissue. Transformation to malignancy has been described but is uncommon with an estimated risk of 5%. It is 1.5-2 times as prevalent in males versus females. Symptoms which patients may complain of include pain;locking and giving way; and palpable masses. The management usually entails removal of the mass lesion with or without accompanying synovectomy. Recurrence of disease may occur in up to 15-23% of patients., Conclusion: Synovial chrondromatosis is a rare but well recognised condition. Long term follow up is advised in view of the risk of recurrence and malignant transformation., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Across vertebrates, the mesolimbic reward system is a highly conserved neural network that serves to evaluate the salience of environmental stimuli, with dopamine as the neurotransmitter most relevant to its function. Although brain regions in the dopaminergic reward system have been well characterized in mammals, homologizing these brain areas with structures in teleosts has been controversial, especially for the mesencephalo-diencephalic dopaminergic cell populations. Here we examine the neurochemical profile of five dopaminergic cell groups (Vc, POA, PPr, TPp, pTn) in the model cichlid Astatotilapia burtoni to better understand putative homology relationships between teleosts and mammals. We characterized in the adult brain the expression patterns of three genes (etv5, nr4a2, and pitx3) that either specify dopaminergic cell fate or maintain dopaminergic cell populations. We then determined whether these genes are expressed in dopaminergic cells. We find many striking similarities in these gene expression profiles between dopaminergic cell populations in teleosts and their putative mammalian homologs. Our results suggest that many of these dopaminergic cell groups are indeed evolutionarily ancient and conserved across vertebrates., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Tremendous progress has been made in our understanding of the ultimate and proximate mechanisms underlying social behavior, yet an integrative evolutionary analysis of its underpinnings has been difficult. In this review, we propose that modern genomic approaches can facilitate such studies by integrating four approaches to brain and behavior studies: (1) animals face many challenges and opportunities that are ecologically and socially equivalent across species; (2) they respond with species-specific, yet quantifiable and comparable approach and avoidance behaviors; (3) these behaviors in turn are regulated by gene modules and neurochemical codes; and (4) these behaviors are governed by brain circuits such as the mesolimbic reward system and the social behavior network. For each approach, we discuss genomic and other studies that have shed light on various aspects of social behavior and its underpinnings and suggest promising avenues for future research into the evolution of neuroethological systems., (Copyright © 2010 Elsevier Inc. All rights reserved.)

The gonadal steroid hormone progesterone plays an important role across all vertebrates in mediating female reproductive physiology and behavior. Many effects of progesterone are mediated by a nuclear progesterone receptor (PR), which is crucial for integration of external signals and internal physiological cues in the brain to produce an appropriate behavioral output. The túngara frog, Physalaemus pustulosus, is an excellent model system for the study of mechanisms by which sensory signals, such as auditory communication, are processed within neural circuits where mate choice decisions are made. To establish a framework for studying the neural basis of mate choice and social behavior in this species, we first describe the cytoarchitecture of the brain using Nissl-stained sections. Then, in order to better understand where progesterone acts to regulate social decisions, we determined the distribution of PR protein throughout the brain of P. pustulosus by immunohistochemistry. We found PR immunoreactivity in key brain regions known to modulate the processing of auditory cues and social behavior in other vertebrates. Due to its widespread distribution, PR likely also plays important roles in non-limbic brain regions that mediate non-social information processing. Further, we have colocalized PR with tyrosine hydroxylase, providing a functional context for the role of progesterone in mediating motivation and motor behavior. Our results significantly extend our understanding of hormonal modulation in the anuran brain and support the important role of the nuclear progesterone receptor in modulating female mate choice and receptivity in amphibians and across vertebrates., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Progesterone and its nuclear receptor are critical in modulating reproductive physiology and behavior in female and male vertebrates. Whiptail lizards (genus Cnemidophorus) are an excellent model system in which to study the evolution of sexual behavior, as both the ancestral and descendent species exist. Male-typical sexual behavior is mediated by progesterone in both the ancestral species and the descendant all-female species, although the molecular characterization and distribution of the progesterone receptor protein throughout the reptilian brain is not well understood. To better understand the gene targets and ligand binding properties of the progesterone receptor in whiptails, we cloned the promoter and coding sequence of the progesterone receptor and analyzed the predicted protein structure. We next determined the distribution of the progesterone receptor protein and mRNA throughout the brain of Cnemidophorus inornatus and Cnemidophorus uniparens by immunohistochemistry and in situ hybridization. We found the progesterone receptor to be present in many brain regions known to regulate social behavior and processing of stimulus salience across many vertebrates, including the ventral tegmental area, amygdala, nucleus accumbens and several hypothalamic nuclei. Additionally, we quantified immunoreactive cells in the preoptic area and ventromedial hypothalamus in females of both species and males of the ancestral species. We found differences between both species and across ovarian states. Our results significantly extend our understanding of progesterone modulation in the reptilian brain and support the important role of the nuclear progesterone receptor in modulating sexual behavior in reptiles and across vertebrates., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Dopamine is an evolutionarily ancient neurotransmitter that plays an essential role in mediating behavior. In vertebrates, dopamine is central to the mesolimbic reward system, a neural network concerned with the valuation of stimulus salience, and to the nigrostriatal motor system and hypothalamic nuclei involved in the regulation of locomotion and social behavior. In amphibians, dopaminergic neurons have been mapped out in several species, yet the distribution of dopaminoreceptive cells is unknown. The túngara frog, Physalaemus pustulosus, is an excellent model system for the study of neural mechanisms by which valuations of stimuli salience and social decisions are made, especially in the context of mate choice. In order to better understand where dopamine acts to regulate social decisions in this species, we have determined the distribution of putative dopaminergic cells (using tyrosine hydroxylase immunohistochemistry) and cells receptive to dopaminergic signaling (using DARPP-32 immunohistochemistry) throughout the brain of P. pustulosus. The distribution of dopaminergic cells was comparable to other anurans. DARPP-32 immunoreactivity was identified in key brain regions known to modulate social behavior in other vertebrates including the proposed anuran homologues of the mammalian amygdalar complex, nucleus accumbens, hippocampus, striatum, preoptic area, anterior hypothalamus, ventromedial hypothalamus, and ventral tegmental area/substantia nigra pars compacta. Due to its widespread distribution, DARPP-32 likely also plays many roles in non-limbic brain regions that mediate non-social information processing. These results significantly extend our understanding of the distribution of the dopaminergic system in the anuran brain and beyond., (Copyright © 2010 S. Karger AG, Basel.)