A surfactant-based dressing can reduce the appearance of Pseudomonas aeruginosa pigments and uncover the dermal extracellular matrix in an ex vivo porcine skin wound model.

From previous studies, we have shown that viable colony forming units of bacteria and bacterial biofilms are reduced after sequential treatment with a surfactant-based dressing. Here, we sought to test the impact on visible bacterial pigments and the ultrastructural impact following the sequential treatment of the same surfactant-based dressing. Mature Pseudomonas aeruginosa biofilms were grown on ex vivo porcine skin explants, and an imaging-based analysis was used to compare the skin with and without a concentrated surfactant. In explants naturally tinted by bacterial chromophores, wiping alone had no effect, while the use of a surfactant-based dressing reduced coloration. Similarly, daily wiping led to increased immunohistochemical staining for P. aeruginosa antigens, but not in the surfactant group. Confocal immunofluorescent imaging revealed limited bacterial penetration and coating of the dermis and loose pieces of sloughing material. Ultrastructural analysis confirmed that the biofilms were masking the extracellular matrix (ECM), but the surfactant could remove them, re-exposing the ECM. The masking of the ECM may provide another non-inflammatory explanation for delayed healing, as the ECM is no longer accessible for wound cell locomotion. The use of a poloxamer-based surfactant appears to be an effective way to remove bacterial chromophores and the biofilm coating the ECM fibres.

Dopamine Release Plateau and Outcome Signals in Dorsal Striatum Contrast with Classic Reinforcement Learning Formulations.

We recorded dopamine release signals in medial and lateral sectors of the striatum as mice learned consecutive visual cue-outcome conditioning tasks including cue association, cue discrimination, reversal, and probabilistic discrimination task versions. Dopamine release responses in medial and lateral sites exhibited learning-related changes within and across phases of acquisition. These were different for the medial and lateral sites. In neither sector could these be accounted for by classic reinforcement learning as applied to dopamine-containing neuron activity. Cue responses ranged from initial sharp peaks to modulated plateau responses. In the medial sector, outcome (reward) responses during cue conditioning were minimal or, initially, negative. By contrast, in lateral sites, strong, transient dopamine release responses occurred at both cue and outcome. Prolonged, plateau release responses to cues emerged in both regions when discriminative behavioral responses became required. In most sites, we found no evidence for a transition from outcome to cue signaling, a hallmark of temporal difference reinforcement learning as applied to midbrain dopamine activity. These findings delineate reshaping of dopamine release activity during learning and suggest that current views of reward prediction error encoding need review to accommodate distinct learning-related spatial and temporal patterns of striatal dopamine release in the dorsal striatum.

The association of wound factors and symptoms of fatigue and pain with wound healing in chronic venous leg ulcers.

The purpose of this study was: (1) to characterise the association of wound area, wound exudate C-reactive protein (CRP), broad-spectrum matrix metalloprotease protein (MMPs), and symptoms of fatigue and pain in individuals with chronic venous leg ulcers (CVLUs) over time and (2) to identify factors associated with the wound healing trajectory in CVLUs. Seventy four participants with CVLU who received weekly sharp debridement were recruited from a wound care clinic during the 8-week study period. To examine associations among wound CRP, MMPs, pain, fatigue, and wound healing trajectory over time, we calculated Bayes factors (BF) based on a linear mixed model. The mean age of participants was 71.8 (SD = 9.8) and the mean wound area was 2278 mm2 (SD = 7085 mm2 ) at baseline. Higher fatigue was strongly associated with higher MMPs (BF = 9, 95% HDI: [-.05, .43]), lower CRP (BF = 11, 95% HDI: [-.02, .002]), and large areas of wound (BF = 20, 95% HDI: [-.001, .01]). Higher CRP and MMPs activity in wound exudate and higher fatigue were associated with a larger wound area. To facilitate wound healing, clinicians need to utilise the multifactorial approach, which includes wound treatment and management of symptoms such as pain and fatigue, because of the molecular and psycho-behavioural factors involved in wound healing.

Synchronous Measurements of Extracellular Action Potentials and Neurochemical Activity with Carbon Fiber Electrodes in Nonhuman Primates.

Measuring the dynamic relationship between neuromodulators, such as dopamine, and neuronal action potentials is imperative to understand how these fundamental modes of neural signaling interact to mediate behavior. Here, we developed methods to measure concurrently dopamine and extracellular action potentials (i.e., spikes) and applied these in a monkey performing a behavioral task. Standard fast-scan cyclic voltammetric (FSCV) electrochemical (EChem) and electrophysiological (EPhys) recording systems are combined and used to collect spike and dopamine signals, respectively, from an array of carbon fiber (CF) sensors implanted in the monkey striatum. FSCV requires the application of small voltages at the implanted sensors to measure redox currents generated from target molecules, such as dopamine. These applied voltages create artifacts at neighboring EPhys-measurement sensors, producing signals that may falsely be classified as physiological spikes. Therefore, simple automated temporal interpolation algorithms were designed to remove these artifacts and enable accurate spike extraction. We validated these methods using simulated artifacts and demonstrated an average spike recovery rate of 84.5%. This spike extraction was performed on data collected from concurrent EChem and EPhys recordings made in a task-performing monkey to discriminate cell-type specific striatal units. These identified units were shown to correlate to specific behavioral task parameters related to reward size and eye-movement direction. Synchronous measures of spike and dopamine signals displayed contrasting relations to the behavioral task parameters, as taken from our small set of representative data, suggesting a complex relationship between these two modes of neural signaling. Future application of our methods will help advance our understanding of the interactions between neuromodulator signaling and neuronal activity, to elucidate more detailed mechanisms of neural circuitry and plasticity mediating behaviors in health and in disease.

Therapeutic effects of equine amniotic membrane suspension on corneal re-epithelialization and haze in a modified lagomorph ex vivo wound healing model.

OBJECTIVE: To investigate the therapeutic effects of topical equine amniotic membrane (eAM) suspension following corneal wounding in a controlled experimental setting. PROCEDURES: Equine amniotic membrane was collected, gamma irradiated, homogenized for topical suspension preparation, and cryopreserved. Corneoscleral rims harvested from fresh rabbit globes were wounded via keratectomy and were maintained in an air-liquid interface ex vivo corneal culture model. Treatment groups included topical gamma irradiated eAM suspension (n = 20) and a control group (n = 20). Re-epithelialization of the wound was assessed with daily photographic evaluation of area of fluorescein uptake (mm2 ). Corneal wound haze after a 21-day period was assessed by photographic analysis of haze area (mm2 ) and pixel intensity (0-255). Histologic processing of corneal tissue was performed, and protein identification of eAM suspension using Liquid chromatography-mass spectrometry (LC-MS). RESULTS: The average day of complete corneal re-epithelialization in controls (5.5 ± 1.1) and topically treated (5.5 ± 0.6) corneas, and rates of reduction in area of fluorescein uptake over time did not significantly differ (p = .44). The corneal wound haze was significantly reduced in mean area by approximately 52% and intensity by 57% in corneas treated with topical eAM suspension (p < .05), compared to controls 21 days following wounding. Protein analysis identified numerous proteins, specifically decorin, dermatopontin, and lumican, which have previously been documented in eAM. CONCLUSIONS: Area and intensity of corneal wound haze were significantly reduced in corneas treated with gamma irradiated eAM suspension, which may be due to previously identified therapeutic proteins which promote corneal clarity.

A Comparison of the Biomechanical Performance of 3 Negative Pressure Wound Therapy Foams.

PURPOSE: The purpose of this study was to compare 3 foam dressings to (1) determine the biomechanical performance of existing negative pressure wound therapy (NPWT) foams and (2) to determine if a test foam is possibly suitable as an antimicrobial "white" foam alternative for use in NPWT. DESIGN: A comparison of mechanical performance of 3 foams used for vacuum-assisted NPWT. SUBJECTS AND SETTING: Preclinical laboratory study using an in vitro model. METHODS: The performance of a "white" foam (polyvinyl alcohol [PVA]), an antimicrobial "black" foam (polyurethane [PU]), and an antimicrobial white foam alternative (test PVA) were tested and compared using 3 mechanically relevant criteria. First, the fluid removal rate was measured for 72 hours. Next, the pressure input was compared to the pressure directly beneath the center of the foam. Finally, the spread of negative pressure beneath the foam was measured and compared. RESULTS: Significant differences were found in fluid removal rates; specifically, the PU foam removed fluids faster than the PVA and test PVA foams, and the currently available PVA foams performed similarly. Both the PU and test PVA foams were able to transmit the negative pressure through the center of the dressing, while the typical PVA foam began failing at 140 mm Hg, with 50% of the samples failing at 200 mm Hg. All PU replicate foams evenly distributed the pressure, while 47% to 60% of the test PVA foams and 7% of the typical PVA foams distributed pressures evenly. CONCLUSIONS: Study findings suggest that the test PVA foam does not mechanically interfere with NPWT and performs equivalently to currently used foams. These results suggest that the test PVA may be modified and incorporated into a vacuum-assisted NPWT device. In addition, the methods employed in these experiments provide a reproducible means to compare biomechanical compatibility of various NPWT foams, dressings, and subdrape devices.

Lymphoma in Psittacine Birds: A Histological and Immunohistochemical Assessment.

In psittacine birds, round cell neoplasms that originate from lymphocytes, plasma cells, histiocytes, or mast cells are sporadic and poorly described. The lack of morphological and immunohistochemical diagnostic criteria or grading schemes make specific diagnoses and prognoses challenging. We assessed cases of psittacine birds diagnosed with round cell neoplasia from 3 North American veterinary diagnostic laboratories to describe the diagnostic features of these tumors. For all cases, demographic data, anatomic distribution, histological features, and immunoreactivity for T (CD3) and B (Pax5 and MUM-1) cell markers were assessed using tissue microarrays and whole slide mounts. Thirty-eight psittacine birds representing 14 species were included. Tumors were mainly infiltrative and multicentric, were composed of homogenous sheets of round to polygonal cells, and commonly presented with a high mitotic count (average 21 mitoses per high-power field). Based on Pax5 immunoreactivity, B-cell lymphoma was most common (19/38 [50%]), and was significantly associated with involvement of the gastrointestinal and urogenital systems. Of the 38 cases, 6 (16%) were consistent with T-cell lymphoma, 3 (8%) with plasma cell tumor, and 3 (8%) were double-reactive for both B- and T-lymphocyte markers. This is the first study to describe morphologic and immunohistochemical features of round cell neoplasia in a large number of psittacine birds, and provides benchmark data for future studies aimed at elucidating the diagnosis and prognosis of these neoplasms. These data also provide useful information about reactivity of commercially available antibodies as lymphocyte markers in tissues of multiple psittacine species.

Determining MMP-2 and MMP-9 reductive activities of bovine and equine amniotic membranes homogenates using fluorescence resonance energy transfer.

INTRODUCTION: Matrix metalloproteinases (MMPs)-2 and -9 are present in corneal ulcers, and an imbalance between MMPs and tissue inhibitors of metalloproteinases (TIMPs) leads to further corneal degradation. Amniotic membrane homogenate (AMH) has proteolytic properties beneficial for corneal healing, but it is unknown whether AMH possesses TIMPs or effectively inhibits MMP-2 and MMP-9 activity. OBJECTIVE: To determine if bovine and equine AMH reduce in vitro MMP-2 and MMP-9 activities associated with the presence of TIMPs. PROCEDURES: Undiluted and diluted twofold series (0-fold to 16-fold dilutions) of equine amniotic membrane homogenates (EAMH, n = 8) and bovine amniotic membrane homogenates (BAMH, n = 8) were subjected to fluorescence resonance energy transfer, and the fluorescence emitted was recorded over time. Average fluorescence was calculated versus recombinant concentration. Enzyme-linked immunosorbent assays for TIMPs 1-4 were applied to quantify TIMPs in the samples. RESULTS: AMH from both species were able to inhibit MMP-2 and MMP-9 activities in vitro, and the inhibition efficacy decreased gradually with dilution. BAMH was significantly more effective than EAMH at inhibiting MMP-2 and MMP-9 in vitro. TIMPs -2 and -3 were present in EAMH and BAMH. TIMP-1 was detected only in BAMH, and TIMP-4 was not detected in any samples. CONCLUSION: Both EAMH and BAMH directly inhibited MMP-2 and MMP-9 in vitro without dilution, and BAMH showed better inhibition of MMP-2 and MMP-9 before and after dilution compared to EAMH.

An ex vivo cornea infection model.

In vitro screening and testing of drugs and devices is necessary, but in vitro conditions differ greatly from those found in vivo. These differences can lead to false promises of efficacy, or can hide problems of tissue compatibility. Models with ex vivo tissues can be highly valuable bridges which provide relevant matrices for testing [1], [2], [3], [4], [5], [6], [7], [8], [9]. Ex vivo tissue models which are closer both biochemically and biophysically can provide useful feedback in a more time- and cost-efficient manner. Herein we describe an ex vivo corneal model for use in drug delivery testing and corneal infection modeling [10]. The protocol covers the tissue harvesting, sterilization, inoculation, and bacterial load quantification. We envision that the model can be used to study bacterial physiology on metabolizable matrices and to study the direct effects of microbial colonization on the cornea's integrity and clarity.•Devitalized cornea.•Non-submersed conditions.•Contact lens compatible.

A Comparison of the Biomechanical Protection Provided by 2 Cyanoacrylate-Based Skin Protectants: A Comparison Cohort Study.

PURPOSE: The purpose of this study was to evaluate the in-gel strain and tear reduction provided by 2 skin protectant products that were applied as a liquid and allowed to dry, leaving behind a protective layer. DESIGN: Prospective, 3-group comparison cohort study using an in vitro model. METHODS: A fragile agar-based gel with an embedded bead was used in a custom device that applied variable interface pressures of 550, 1080, or 1600 Pa, respectively. The device then imparted 216 N of external shear force in 0.625-mm increments. The resulting strain in the gel was measured by digital image correlation. The strain at tearing was determined by observing the images of the gels and calculating the strain at that point. This approach was used to compare untreated gels to gels treated with one of 2 commercially available cyanoacrylate-based skin protectants. The results from the 3 groups were first analyzed by analysis of variance, followed by Tukey's Honestly Significant Difference test when indicated. RESULTS: We observed a proportional increase in interface pressure and strain that differed among the 3 groups. Specifically, the gels treated with a mixed polymer skin protectant had less pretearing strain than the control gel at both the 1080-Pa load (-15%, P = 3.64 × 10) and 1600 Pa-load (-20%, P = .03). The pure cyanoacrylate-treated gels had less strain than the control at 1080 Pa (-34%, P = 4.25 × 10) and 1600 Pa (-48%, P = 1.07 × 10); it also had less strain than the mixed polymer product at 1080 Pa (-19%, P = 5.38 × 10) and 1600 Pa (-28%, P = 3.88 × 10). In terms of protection from tearing, at an interface pressure of 1080 Pa, the control gel tore 80% of the time, the mixed polymer-treated gel tore 100% of the time, and the pure cyanoacrylate-treated gel did not tear (0/5, P = 8.84 × 10). Under a load of 1600 Pa, 100% of the control and mixed polymer-treated gels tore while none of the cyanoacrylate-treated gels did (P = 2.54 × 10). CONCLUSION: The pure cyanoacrylate-based skin protectant provided the most protection, with consistent reductions in both strain and tearing. Both skin protectants reduced the initial in-gel strain; however, only the pure cyanoacrylate-treated product protected the gel from tears under the conditions tested. These results indicate that cyanoacrylate-based skin protectants can reduce shear strain and tearing in fragile elastic materials.

Striatal Beta Oscillation and Neuronal Activity in the Primate Caudate Nucleus Differentially Represent Valence and Arousal Under Approach-Avoidance Conflict.

An approach-avoidance (Ap-Av) conflict arises when an individual has to decide whether to accept or reject a compound offer that has features indicating both reward and punishment. During value judgments of likes and dislikes, arousal responses simultaneously emerge and influence reaction times and the frequency of behavioral errors. In Ap-Av decision-making, reward and punishment differentially influence valence and arousal, allowing us to dissociate their neural processing. The primate caudate nucleus (CN) has been implicated in affective judgment, but it is still unclear how neural responses in the CN represent decision-related variables underlying choice. To address this issue, we recorded spikes and local field potentials (LFPs) from the CN while macaque monkeys performed an Ap-Av decision-making task. We analyzed 450 neuronal units and 667 beta oscillatory activities recorded during the performance of the task. To examine how these activities represented valence, we focused on beta-band responses and unit activities that encoded the chosen value (ChV) of the compound offer as derived from an econometric model. Unit activities exhibited either positive (65.0% = 26/40) or negative (35.0% = 14/40) correlations with the ChV, whereas beta responses exhibited almost exclusively positive correlations with the ChV (98.4% = 62/63). We examined arousal representation by focusing on beta responses and unit activities that encoded the frequency of omission errors (FOE), which were negatively correlated with arousal. The unit activities were either positively (65.3% = 17/26) or negatively (34.6% = 9/26) correlated with the FOE, whereas the beta responses were almost entirely positively correlated with the FOE (95.8% = 23/24). We found that the temporal onset of the beta-band responses occurred sequentially across conditions: first, the negative-value, then low-arousal, and finally, high-value conditions. These findings suggest the distinctive roles of CN beta oscillations that were sequentially activated for the valence and arousal conditions. By identifying dissociable groups of CN beta-band activity responding in relation to valence and arousal, we demonstrate that the beta responses mainly exhibited selective activation for the high-valence and low-arousal conditions, whereas the unit activities simultaneously recorded in the same experiments responded to chosen value and other features of decision-making under approach-avoidance conflict.

Efficacy of the NICHD vaginal birth after cesarean delivery calculator: a single center experience.

Objective: As the cesarean delivery rate has risen future pregnancy outcomes are impacted including the decision to undergo a repeat cesarean or a vaginal birth after cesarean (VBAC) in the subsequent pregnancy. A calculator was developed by the maternal fetal medicine units (MFMUs) network in 2007 to estimate the chance of successful VBAC and is used widely. The purpose of this study was to investigate the calculator's validity on our obstetric patient population.Study design: This was a retrospective study of patients attempting a VBAC delivery at a single center from January 2012 to June 2014. Chances for success were estimated using the MFMU network VBAC calculator in 201 evaluable patients. We then compared the calculator's results with the outcomes observed. In order to determine if the MFMU VBAC calculator was accurately predicting successful vaginal deliveries, we discretized our dataset by binning into MFMU score deciles. Each decile was then tested for significant deviations from the predicted success rate using an exact binomial test. Significance was determined at 0.05 levels.Results: Two hundred and one patients were included. Our results demonstrated higher actual VBAC success than anticipated by using the MFMU network calculator for patients with scores in the 40-80% decile range. When stratified by race, we found the calculator to be a better predictor of success in African-American patients, as the calculator appears to underestimate success in white and Hispanic patients.Conclusion: Calculators are helpful to facilitate patient counseling and shared decision-making regarding the patient's choice for VBAC. When providing such counseling, the potential for reduced predicted VBAC success in the mid-decile range with the MFMU calculator should be recognized.

Development and assessment of a novel ex vivo corneal culture technique involving an agarose-based dome scaffold for use as a model of in vivo corneal wound healing in dogs and rabbits.

OBJECTIVE: To develop and assess a novel ex vivo corneal culture technique involving an agarose-based dome scaffold (ABDS) for use as a model of in vivo corneal wound healing in dogs and rabbits. SAMPLE: Corneas from clinically normal dogs (paired corneas from 8 dogs and 8 single corneas) and rabbits (21 single corneas). PROCEDURES: 8 single dog corneas (DCs), 1 DC from each pair, and 10 rabbit corneas (RCs) were wounded with an excimer laser; 1 DC from each pair and 11 RCs remained unwounded. Corneas were cultured for 21 days on ABDSs (8 pairs of DCs and all RCs) or on flat-topped scaffolds (8 single DCs). The surface area of corneal fluorescein retention was measured every 6 (DCs) or 12 (RCs) hours until full corneal epithelialization was detected. Changes in corneal clarity were evaluated at 0, 7, 14, and 21 days. RESULTS: Median time to full epithelialization for wounded dog and rabbit corneas was 48 and 60 hours, respectively; among wounded DCs, time to full epithelization did not differ by scaffold type. After 21 days of culture on ABDSs, all DCs and RCs that epithelialized developed a circular, diffuse, cloud-like pattern of optical haze, whereas DCs cultured on flat-topped scaffolds developed a focal, crater-like region of optical haze. All corneas on the ABDSs maintained convex curvature throughout the study. CONCLUSIONS AND CLINICAL RELEVANCE: Wounded ex vivo DCs and RCs cultured on ABDSs reliably epithelialized, formed optical haze (consistent with in vivo wound healing), and maintained convex curvature. This culture technique may be adaptable to other species.

Development and use of a triplex real-time PCR assay for detection of three DNA viruses in psittacine birds.

Aves polyomavirus 1, psittacine beak and feather disease virus, and psittacid herpesvirus 1 are important pathogens of psittacine birds with the potential to cause substantial morbidity and mortality. Using publically available nucleotide sequences, we developed and validated a triplex real-time PCR (rtPCR) assay to rapidly detect these 3 viruses. The assay had high analytical sensitivity, detecting <6 copies of viral DNA per reaction, and 100% analytical specificity, showing no cross-reactivity with 59 other animal pathogens. Archived formalin-fixed, paraffin-embedded tissues from psittacine birds diagnosed at postmortem as infected with each of the viruses as well as virus-negative birds were used to validate the utility of the assay. Birds were selected for the positive cohort if they showed histologic evidence of infection (i.e., characteristic inclusion bodies in tissues); birds in the negative cohort had final diagnoses unrelated to the pathogens of interest. The triplex rtPCR assay confirmed 98% of histopathology-positive cases, and also identified subclinical infections that were not observed by histologic examination, including coinfections. Birds that tested positive only by rtPCR had significantly higher cycle threshold values compared to those with histologic evidence of infection. Positive, negative, and overall percentage agreements as well as the kappa statistic between the results of the assay and histopathology were high, demonstrating the usefulness of the assay as a tool to confirm disease diagnoses, and to improve detection of subclinical infections.

Biobehavioral Mechanisms Associated With Nonhealing Wounds and Psychoneurologic Symptoms (Pain, Cognitive Dysfunction, Fatigue, Depression, and Anxiety) in Older Individuals With Chronic Venous Leg Ulcers.

The prevalence and incidence of chronic venous leg ulcers (CVLUs) are increasing worldwide, as are the associated financial costs. Although it has long been known that their underlying etiology is venous insufficiency, the molecular aspects of healing versus nonhealing, as well as the psychoneurologic symptoms (PNS; pain, cognitive dysfunction, fatigue, depression, and anxiety) associated with CVLUs remain understudied. In this biobehaviorally focused review, we aim to elucidate the complex mechanisms that link the biological and molecular aspects of CLVUs with their PNS. Innovations in "omics" research have increased our understanding of important wound microenvironmental factors (e.g., inflammation, microbial pathogenic biofilm, epigenetic processes) that may adversely alter the wound bed's molecular milieu so that microbes evade immune detection. Although these molecular factors are not singularly responsible for wound healing, they are major components of wound development, nonhealing, and PNS that, until now, have not been amenable to systematic study, especially over time. Further, this review explores our current understanding of the molecular mechanisms by which the immune activation that contributes to the development and persistence of CVLUs also leads to the development, persistence, and severity of wound-related PNS. We also make recommendations for future research that will expand the field of biobehavioral wound science. Biobehavioral research that focuses on the interrelated mechanisms of PNS will lead to symptom-management interventions that improve quality of life for the population burdened by CVLUs.

Cadexomer iodine effectively reduces bacterial biofilm in porcine wounds ex vivo and in vivo.

Biofilms are prevalent in non-healing chronic wounds and implicated in delayed healing. Tolerance to antimicrobial treatments and the host's immune system leave clinicians with limited interventions against biofilm populations. It is therefore essential that effective treatments be rigorously tested and demonstrate an impact on biofilm across multiple experimental models to guide clinical investigations and protocols. Cadexomer iodine has previously been shown to be effective against biofilm in various in vitro models, against methicillin-resistant Staphylococcus aureus biofilm in mouse wounds, and clinically in diabetic foot ulcers complicated by biofilm. Similarities between porcine and human skin make the pig a favoured model for cutaneous wound studies. Two antiseptic dressings and a gauze control were assessed against mature biofilm grown on ex vivo pig skin and in a pig wound model. Significant reductions in biofilm were observed following treatment with cadexomer iodine across both biofilm models. In contrast, silver carboxymethylcellulose dressings had minimal impact on biofilm in the models, with similar results to the control in the ex vivo model. Microscopy and histopathology indicate that the depth of organisms in wound tissue may impact treatment effectiveness. Further work on the promising biofilm efficacy of cadexomer iodine is needed to determine optimal treatment durations against biofilm.

Predominant Striatal Input to the Lateral Habenula in Macaques Comes from Striosomes.

Striosomes, neurochemically specialized modules in the striatum, are thought to be nodes in circuits extending, via basal ganglia pathways, from mood-related neocortical regions to dopamine-containing neurons of the substantia nigra. Yet striosomes have remained beyond the reach of electrophysiological methods to identify them, especially in non-human primates. Such work is needed for translational as well as for basic science. Here we introduce a method to identify striosomes on-line in awake, behaving macaques. We combined electrical microstimulation of the striatum with simultaneous electrophysiological recording in the lateral habenula (LHb) followed by immunohistochemistry. We demonstrate that striosomes provide the predominant striatal input to the macaque pallido-habenular circuit, which is known to function in relation to reinforcement signaling. Further, our experiments suggest that striosomes from different striatal regions may convergently influence the lateral habenula. This work now opens the way to defining the functions of striosomes in behaving primates in relation to mood, motivation, and action.

Bayesian Phylogenetic Analysis of Avipoxviruses from North American Wild Birds Demonstrates New Insights into Host Specificity and Interspecies Transmission.

Avian pox is commonly diagnosed in a variety of North American wild and domestic birds, yet little is known about the evolutionary relationships among the causative poxviruses. This study aimed to determine the phylogenetic relationships among isolates identified in different avian host species to better characterize the host range of specific viral strains and compare the genetic variability within and between viral clades. Skin lesions grossly and microscopically consistent with poxvirus infection from 82 birds collected in Canada, the United States, and the U.S. Virgin Islands were included in this study. A total of 12 avian species were represented; the most common species sampled were wild turkeys (Meleagris gallopavo), mourning doves (Zenaida macroura), and American crows (Corvus brachyrhynchos). Poxvirus samples from these birds were genotyped using PCR that targeted the 4b core protein gene followed by amplicon sequencing. Bayesian phylogenetic analyses of these viruses, in conjunction with publicly available sequences, representing avipoxvirus strains from six continents revealed statistically significant monophyletic clades based on genetic distances of sequences within and between observed clades. Genetic variation within the fowlpox clade was low compared to the canarypox clade. Host and geographic origins of viral isolates revealed overall clustering of viral strains within avian species, with a few exceptions. No genetic differences were observed between viruses from Canada and the United States within individual species. These results are novel in their characterization and comparison of the phylogenetic relationships of poxvirus isolates in wild bird species from North America. Further, we provide new data on the level of host specificity and specific strains circulating in North America.

El análisis filogenético bayesiano de los avipoxvirus de las aves silvestres de América del Norte demuestra nuevos conocimientos sobre la especificidad del huésped y la transmisión interespecífica. La viruela aviar se diagnostica comúnmente en una variedad de aves silvestres y domésticas de América del Norte, pero se sabe poco sobre las relaciones evolutivas entre los poxvirus. Este estudio tuvo como objetivo determinar las relaciones filogenéticas entre aislamientos identificados en diferentes especies de hospedadores aviares para caracterizar mejor el rango de hospedadores de cepas virales específicas y comparar la variabilidad genética dentro y entre los clados virales. Se incluyeron en este estudio lesiones cutáneas que eran consistentes macro y microscópicamente con la infección por poxvirus de 82 aves recolectadas en Canadá, Estados Unidos y las Islas Vírgenes de los Estados Unidos. Un total de 12 especies de aves fueron representadas; las especies más comunes en la muestra fueron los pavos silvestres (Meleagris gallopavo), huilota común (Zenaida macroura) y cuervos americanos (Corvus brachyrhynchos). Las muestras de poxvirus de estas aves fueron genotipadas mediante PCR que se enfocó en el gene de la proteína central 4b seguido de secuenciación de amplicón. Los análisis filogenéticos bayesianos de estos virus, junto con las secuencias disponibles públicamente, que representan cepas de avipoxvirus de seis continentes revelaron clados monofiléticos estadísticamente significativos basados en distancias genéticas de las secuencias dentro y entre los clados observados. La variación genética dentro del clado de la viruela del pollo fue baja en comparación con el clado de virus de canario. El huésped y los orígenes geográficos de los aislamientos virales revelaron un agrupamiento general de cepas virales dentro de las especies aviares, con algunas excepciones. No se observaron diferencias genéticas entre los virus de Canadá y los Estados Unidos dentro de las especies individuales. Estos resultados son novedosos en la caracterización y comparación de las relaciones filogenéticas de los aislados de poxvirus en especies de aves silvestres de América del Norte. Además, se proporcionan nuevos datos sobre el nivel de especificidad del huésped y las cepas específicas que circulan en América del Norte. Key words: Bayesian analysis, mourning dove, phylogenetic, poxvirus, sequencing, wild turkey, 4b gene.

Striatal Microstimulation Induces Persistent and Repetitive Negative Decision-Making Predicted by Striatal Beta-Band Oscillation.

Persistent thoughts inducing irrationally pessimistic and repetitive decisions are often symptoms of mood and anxiety disorders. Regional neural hyperactivities have been associated with these disorders, but it remains unclear whether there is a specific brain region causally involved in these persistent valuations. Here, we identified potential sources of such persistent states by microstimulating the striatum of macaques performing a task by which we could quantitatively estimate their subjective pessimistic states using their choices to accept or reject conflicting offers. We found that this microstimulation induced irrationally repetitive choices with negative evaluations. Local field potentials recorded in the same microstimulation sessions exhibited modulations of beta-band oscillatory activity that paralleled the persistent negative states influencing repetitive decisions. These findings demonstrate that local striatal zones can causally affect subjective states influencing persistent negative valuation and that abnormal beta-band oscillations can be associated with persistency in valuation accompanied by an anxiety-like state.