Direct evidence of substorm-related impulsive injections of electrons at Mercury.

Mercury's magnetosphere is known to involve fundamental processes releasing particles and energy like at Earth due to the solar wind interaction. The resulting cycle is however much faster and involves acceleration, transport, loss, and recycling of plasma. Direct experimental evidence for the roles of electrons during this cycle is however missing. Here we show that in-situ plasma observations obtained during BepiColombo's first Mercury flyby reveal a compressed magnetosphere hosts of quasi-periodic fluctuations, including the original observation of dynamic phenomena in the post-midnight, southern magnetosphere. The energy-time dispersed electron enhancements support the occurrence of substorm-related, multiple, impulsive injections of electrons that ultimately precipitate onto its surface and induce X-ray fluorescence. These observations reveal that electron injections and subsequent energy-dependent drift now observed throughout Solar System is a universal mechanism that generates aurorae despite the differences in structure and dynamics of the planetary magnetospheres.

Forecasting Heliospheric CME Solar-Wind Parameters Using the UCSD Time-Dependent Tomography and ISEE Interplanetary Scintillation Data: The 10 March 2022 CME.

Remotely sensed interplanetary scintillation (IPS) data from the Institute for Space-Earth Environmental Research (ISEE), Japan, allows a determination of solar-wind parameters throughout the inner heliosphere. We show the 3D analysis technique developed for these data sets that forecast plasma velocity, density, and component magnetic fields at Earth, as well at the other inner heliospheric planets and spacecraft. One excellent coronal mass ejection (CME) example that occurred on the 10 March 2022 was viewed not only in the ISEE IPS analyses, but also by the spacecraft near Earth that measured the CME arrival at one AU. Solar Orbiter, that was nearly aligned along the Earth radial at 0.45 AU, also measured the CME in plasma density, velocity, and magnetic field. BepiColombo at 0.42 AU was also aligned with the STEREO A spacecraft, and viewed this CME. The instruments used here from BepiColombo include: 1) the European-Space-Agency Mercury-Planetary-Orbiter magnetic field measurements; 2) the Japan Aerospace Exploration Agency Mio spacecraft Solar Particle Monitor that viewed the CME Forbush decrease, and the Mercury Plasma Experiment/Mercury Electron Analyzer instruments that measured particles and solar-wind density from below the spacecraft protective sunshield covering. This article summarizes the analysis using ISEE, Japan real-time data for these forecasts: it provides a synopsis of the results and confirmation of the CME event morphology after its arrival, and discusses how future IPS analyses can augment these results.

Single incision laparoscopic appendectomy with surgical-glove port is cost-effective and reliable in complicated acute appendicitis: A casecontrol multicenter study in Colombia.

Background: The single-port (SPL) and multi-port (MPL) laparoscopic approach are the gold standard of management of acute appendicitis, due to its multiple advantages over open surgery, mainly because of its direct effects on recovery, esthetics and costs of the procedure. However, in third-world countries, the laparoscopic approach is not yet fully reproducible due to the costs of the technique. The surgical-glove port single incision laparoscopic appendectomy (SGP-SILA) has been proposed as a viable option. However, it has never been studied in Colombia. Objective: To evaluate the cost-effectiveness and reliability of SGP-SILA in the management of complicated acute appendicitis, compared to traditional MPL approach. Materials and methods: A retrospective case control study was carried out comparing patients undergoing laparoscopic appendectomy by SGP-SILA vs. MPL, evaluating operating costs associated with intraoperative and postoperative variables in two tertiary centers in Bogota, Colombia. The data were analyzed and expressed according to their nature and distribution. Results: 116 patients were included (SGP-SILA: 62 and MPL: 54). The median surgical time for SGP-SILA was 60 min vs. 39 min for MPL. SGP-SILA was shown to cause lower frequency of surgical site infection (4 vs. 8 patients; p = 0.047). It was found a significant correlation between Grade III surgical site infection and surgery time (p = 0.047) in the MPL group; also, with hospital stay (p < 0.001). Also, a lower risk of surgical site infection was found with the SGP-SILA technique (22% vs. 31%). SGP-SILA generated a reduction in both direct and indirect operating costs of approximately 10% (616 USD vs. 683 USD). Conclusion: SGP-SILA and MPL are feasible and comparable procedures in the resolution of complicated acute appendicitis. SGP-SILA turns out to be more cost-effective compared to MPL, due to the use of more easily accessible instruments. This may be a reproducible technique in low- and middle-income countries.

Crown defoliation decreases reproduction and wood growth in a marginal European beech population.

BACKGROUND AND AIMS: Abiotic and biotic stresses related to climate change have been associated with increased crown defoliation, decreased growth and a higher risk of mortality in many forest tree species, but the impact of stresses on tree reproduction and forest regeneration remains understudied. At the dry, warm margin of species distributions, flowering, pollination and seed maturation are expected to be affected by drought, late frost and other stresses, eventually resulting in reproduction failure. Moreover, inter-individual variation in reproductive performance versus other performance traits (growth, survival) could have important consequences for population dynamics. This study investigated the relationships among individual crown defoliation, growth and reproduction in a drought-prone population of European beech, Fagus sylvatica. METHODS: We used a spatially explicit mating model and marker-based parentage analyses to estimate effective female and male fecundities of 432 reproductive trees, which were also monitored for basal area increment and crown defoliation over 9 years. KEY RESULTS: Female and male fecundities varied markedly between individuals, more than did growth. Both female fecundity and growth decreased with increasing crown defoliation and competition, and increased with size. Moreover, the negative effect of defoliation on female fecundity was size-dependent, with a slower decline in female fecundity with increasing defoliation for the large individuals. Finally, a trade-off between growth and female fecundity was observed in response to defoliation: some large trees maintained significant female fecundity at the expense of reduced growth in response to defoliation, while some other defoliated trees maintained high growth at the expense of reduced female fecundity. CONCLUSIONS: Our results suggest that, while decreasing their growth, some large defoliated trees still contribute to reproduction through seed production and pollination. This non-coordinated decline of growth and fecundity at individual level in response to stress may compromise the evolution of stress-resistance traits at population level, and increase forest tree vulnerability.

Bezoar de dinero: reporte de bezoar atípico, su manejo y una revisión de la literatura / Money Bezoar: Report of atypical bezoar, its treatment, and a literature review

Resumen Objetivos: Presentar el manejo laparoscópico en un caso de bezoar atípico y una revisión de la literatura. Materiales y métodos: Se presenta el caso de un paciente de sexo masculino de 67 años con síndrome pilórico debido a una obstrucción intestinal por cuerpo extraño. Resultados: Se encuentra como hallazgo endoscópico un bezoar atípico (bezoar de dinero) impactado en la región prepilórica sin posibilidad de resolución por este medio, por lo cual se considera el manejo laparoscópico. Discusión: Los bezoares se definen como cualquier objeto el cual tuvo una ingesta voluntaria o involuntaria, que se aloja en alguna parte del tracto gastrointestinal superior, con mayor frecuencia a nivel gástrico, y no se puede digerir por los mecanismos fisiológicos del cuerpo; además, se clasifican según su composición. Conclusiones: En pacientes con obstrucción intestinal alta debido a cuerpos extraños en los cuales el manejo endoscópico falla, el manejo quirúrgico mínimamente invasivo con cirugía laparoscópica es viable y eficaz.

Abstract Objectives: To describe the laparoscopic management of an atypical bezoar case and present a literature review. Materials and methods: This is the case of a 67-year-old male patient with pyloric stenosis due to intestinal obstruction by a foreign body. Results: The endoscopic finding was an atypical bezoar (Money bezoar) in the prepyloric region with no possible resolution by this route, so laparoscopic treatment was considered. Discussion: Bezoars are defined as any object that was voluntarily or involuntarily swollen and is obstructing some part of the upper gastrointestinal tract, usually the stomach, and cannot be digested using the physiological mechanisms of the body. They are categorized based on their composition. Conclusions: When endoscopic treatment fails to relieve upper gastrointestinal tract obstruction caused by foreign bodies, minimally invasive surgical treatment with laparoscopic surgery is a viable and efficient option.

Role of DZIP1-CBY-FAM92 transition zone complex in the basal body to membrane attachment and ciliary budding.

Cilia play important signaling or motile functions in various organisms. In Human, cilia dysfunctions are responsible for a wide range of diseases, called ciliopathies. Cilia assembly is a tightly controlled process, which starts with the conversion of the centriole into a basal body, leading to the formation of the ciliary bud that protrudes inside a ciliary vesicle and/or ultimately at the cell surface. Ciliary bud formation is associated with the assembly of the transition zone (TZ), a complex architecture of proteins of the ciliary base which plays critical functions in gating proteins in and out of the ciliary compartment. Many proteins are involved in the assembly of the TZ, which shows structural and functional variations in different cell types or organisms. In this review, we discuss how a particular complex, composed of members of the DZIP1, CBY and FAM92 families of proteins, is required for the initial stages of cilia assembly leading to ciliary bud formation and how their functional hierarchy contributes to TZ assembly. Moreover, we summarize how evidences in Drosophila reveal functional differences of the DZIP1-CBY-FAM92 complex in the different ciliated tissues of this organism. Whereas it is essential for proper TZ assembly in the two types of ciliated tissues, it is involved in stable anchoring of basal bodies to the plasma membrane in male germ cells. Overall, the DZIP1-CBY-FAM92 complex reveals a molecular assembly pathway required for the initial stages of ciliary bud formation and that is conserved from Drosophila to Human.

Glial Endozepines Reverse High-Fat Diet-Induced Obesity by Enhancing Hypothalamic Response to Peripheral Leptin.

Research on energy homeostasis has focused on neuronal signaling; however, the role of glial cells has remained little explored. Glial endozepines exert anorexigenic actions by mechanisms which remain poorly understood. In this context, the present study was designed to decipher the mechanisms underlying the anorexigenic action of endozepines and to investigate their potential curative effect on high-fat diet-induced obesity. We carried out a combination of physiological, pharmacological, and molecular analyses together to dissect the underlying mechanisms of endozepine-induced hypophagia. To evaluate the potential anti-obesity effect of endozepines, different model of obesity were used, i.e., ob/ob and diet-induced obese mice. We show that the intracerebral administration of endozepines enhances satiety by targeting anorexigenic brain circuitry and induces STAT3 phosphorylation, a hallmark of leptin signaling. Strikingly, endozepines are entirely ineffective at reducing food intake in the presence of a circulating leptin antagonist and in leptin-deficient mice (ob/ob) but potentiate the reduced food intake and weight loss induced by exogenous leptin administration in these animals. Endozepines reversed high fat diet-induced obesity by reducing food intake and restored leptin-induced STAT3 phosphorylation in the hypothalamus. Interestingly, we observed that glucose and insulin synergistically enhance tanycytic endozepine expression and release. Finally, endozepines, which induce ERK activation necessary for leptin transport into the brain in cultured tanycytes, require tanycytic leptin receptor expression to promote STAT3 phosphorylation in the hypothalamus. Our data identify endozepines as potential anti-obesity compounds in part through the modulation of the LepR-ERK-dependent tanycytic leptin shuttle.

Una espina en un pajar: espina de pescado alojada en la tiroides / A fish bone in a haystack: fish bone lodged in thyroid

Introducción. La ingestión accidental de cuerpos extraños como espinas de pescado es muy poco frecuente; en ocasiones, pueden alojarse en el esófago y es posible su migración extraluminal. Este accidente se presenta principalmente en países asiáticos por el gran consumo de pescado. La migración extraluminal de una espina de pescado desde el esófago a la glándula tiroides es aún más infrecuente, con pocos reportes en la literatura.Objetivo. Presentar nuestra experiencia en el diagnóstico y manejo quirúrgico de un paciente con un cuerpo extraño (espina de pescado) alojado en la glándula tiroides y, asimismo, hacer una revisión de la literatura científica.Caso clínico. Se presenta una paciente de 53 años, sin antecedentes de importancia y con un cuadro clínico de tres meses de evolución consistente en odinofagia posterior a la ingestión accidental de una espina de pescado. En la ecografía practicada en otra institución se observó un cuerpo extraño alojado en el lóbulo tiroideo izquierdo en relación con la musculatura del esófago. En la tomografía de cabeza y cuello se apreciaba una imagen hiperdensa lineal de 2,6 cm de longitud en la misma localización. En la exploración quirúrgica se encontró tejido fibrótico en la región posterior del lóbulo tiroideo izquierdo y se procedió a practicar una tiroidectomía subtotal izquierda. La evolución posoperatoria fue adecuada.Conclusiones. La migración extraluminal de cuerpos extraños en el tubo digestivo es factible, sobre todo la de las espinas de pescado por su morfología. La tomografía es la herramienta diagnóstica más confiable para detectar cuerpos extraños alojados en la glándula tiroides. Es necesario conocer las posibles complicaciones y, asimismo, optimizar las posibles intervenciones, pues de eso depende el pronóstico clínico del paciente

Introduction: Accidental ingestion of foreign bodies such as fish bones is very rare; sometimes they may lodge in the esophagus, and extraluminal migration is possible. This accident occurs mainly in Asian countries due to the large fish consumption. Extraluminal migration of a fish bone from the esophagus to the thyroid gland is even more infrequent, with few reports in the literature.Objective: To present our experience in the diagnosis and surgical management of a patient with a foreign body (fish bone) lodged in the thyroid gland and to review the scientific literature.Clinical Case: A 53-year-old patient is presented, without a significant history and with a clinical picture of three months of evolution consisting of odynophagia after accidental ingestion of a fish bone. In the ultrasound performed at another institution, a foreign body was observed lodged in the left thyroid lobe in relation to the musculature of the esophagus. Head and neck tomography showed a linear 2.6 cm long hyperdense image at the same location. On surgical exploration, fibrotic tissue was found in the posterior region of the left thyroid lobe and a left subtotal thyroidectomy was performed. Postoperative evolution was adequate.Conclusions: Extraluminal migration of foreign bodies in the digestive tract is feasible, especially that of fish bones due to their morphology. Tomography is the most reliable diagnostic tool to detect foreign bodies lodged in the thyroid gland. It is necessary to know the possible complications and to optimize the possible interventions, since the clinical prognosis of the patient depends on it

Dzip1 and Fam92 form a ciliary transition zone complex with cell type specific roles in Drosophila.

Cilia and flagella are conserved eukaryotic organelles essential for cellular signaling and motility. Cilia dysfunctions cause life-threatening ciliopathies, many of which are due to defects in the transition zone (TZ), a complex structure of the ciliary base. Therefore, understanding TZ assembly, which relies on ordered interactions of multiprotein modules, is of critical importance. Here, we show that Drosophila Dzip1 and Fam92 form a functional module which constrains the conserved core TZ protein, Cep290, to the ciliary base. We identify cell type specific roles of this functional module in two different tissues. While it is required for TZ assembly in all Drosophila ciliated cells, it also regulates basal-body growth and docking to the plasma membrane during spermatogenesis. We therefore demonstrate a novel regulatory role for Dzip1 and Fam92 in mediating membrane/basal-body interactions and show that these interactions exhibit cell type specific functions in basal-body maturation and TZ organization.

salto/CG13164 is required for sperm head morphogenesis in Drosophila.

Producing mature spermatozoa is essential for sexual reproduction in metazoans. Spermiogenesis involves dramatic cell morphological changes going from sperm tail elongation and nuclear reshaping to cell membrane remodeling during sperm individualization and release. The sperm manchette plays a critical scaffolding function during nuclear remodeling by linking the nuclear lamina to the cytoskeleton. Here, we describe the role of an uncharacterized protein in Drosophila, salto/CG13164, involved in nuclear shaping and spermatid individualization. Salto has dynamic localization during spermatid differentiation, being progressively relocated from the sperm-nuclear dense body, which is equivalent to the mammalian sperm manchette, to the centriolar adjunct and acrosomal cap during spermiogenesis. salto-null male flies are sterile and exhibit complete spermatid individualization defects. salto-deficient spermatids show coiled spermatid nuclei at late maturation stages and stalled individualization complexes. Our work sheds light on a novel component involved in cytoskeleton-based cell-morphological changes during spermiogenesis.

Salivary flow and xerostomia in older patients with type 2 diabetes mellitus.

OBJECTIVES: To assess salivary flow in older patients with type 2 diabetes mellitus (DM2) and its association with xerostomia. METHODS: Cross-sectional clinical study conducted with older patients diagnosed with type 2 diabetes for at least one year receiving treatment at the Integrated Center for Diabetes and Hypertension of Ceará (CIHD) in the city of Fortaleza, Ceará, Northeastern Brazil. Oral clinical examination was carried out to assess the decayed, missing and filled teeth index (DMFT). Perception of the presence of xerostomia/dry mouth was assessed using the Visual Analogue Scale. Stimulated salivary flow was measured and samples were obtained using an extra-soft silicone device. RESULTS: 120 older patients with diabetes (60 insulin-dependent and 60 non-insulin-dependent) aged 65-91 years, with a mean age of 72.26 ± 6.53 years, were assessed. Of these, 111 (92.5%) presented a decrease in salivary flow while 59 (49.2%) reported moderate to severe xerostomia/dry mouth. The DMFT Index presented a mean of 27.53 ± 4.86 teeth. CONCLUSIONS: Reduced salivary flow was found in the group assessed in the present research; however, this finding is not in accordance with the perception of xerostomia/dry mouth reported by the patients.

Glial Endozepines Inhibit Feeding-Related Autonomic Functions by Acting at the Brainstem Level.

Endozepines are endogenous ligands for the benzodiazepine receptors and also target a still unidentified GPCR. The endozepine octadecaneuropeptide (ODN), an endoproteolytic processing product of the diazepam-binding inhibitor (DBI) was recently shown to be involved in food intake control as an anorexigenic factor through ODN-GPCR signaling and mobilization of the melanocortinergic signaling pathway. Within the hypothalamus, the DBI gene is mainly expressed by non-neuronal cells such as ependymocytes, tanycytes, and protoplasmic astrocytes, at levels depending on the nutritional status. Administration of ODN C-terminal octapeptide (OP) in the arcuate nucleus strongly reduces food intake. Up to now, the relevance of extrahypothalamic targets for endozepine signaling-mediated anorexia has been largely ignored. We focused our study on the dorsal vagal complex located in the caudal brainstem. This structure is strongly involved in the homeostatic control of food intake and comprises structural similarities with the hypothalamus. In particular, a circumventricular organ, the area postrema (AP) and a tanycyte-like cells forming barrier between the AP and the adjacent nucleus tractus solitarius (NTS) are present. We show here that DBI is highly expressed by ependymocytes lining the fourth ventricle, tanycytes-like cells, as well as by proteoplasmic astrocytes located in the vicinity of AP/NTS interface. ODN staining observed at the electron microscopic level reveals that ODN-expressing tanycyte-like cells and protoplasmic astrocytes are sometimes found in close apposition to neuronal elements such as dendritic profiles or axon terminals. Intracerebroventricular injection of ODN or OP in the fourth ventricle triggers c-Fos activation in the dorsal vagal complex and strongly reduces food intake. We also show that, similarly to leptin, ODN inhibits the swallowing reflex when microinjected into the swallowing pattern generator located in the NTS. In conclusion, we hypothesized that ODN expressing cells located at the AP/NTS interface could release ODN and modify excitability of NTS neurocircuitries involved in food intake control.

Transition zone assembly and its contribution to axoneme formation in Drosophila male germ cells.

The ciliary transition zone (TZ) is a complex structure found at the cilia base. Defects in TZ assembly are associated with human ciliopathies. In most eukaryotes, three protein complexes (CEP290, NPHP, and MKS) cooperate to build the TZ. We show that in Drosophila melanogaster, mild TZ defects are observed in the absence of MKS components. In contrast, Cby and Azi1 cooperate to build the TZ by acting upstream of Cep290 and MKS components. Without Cby and Azi1, centrioles fail to form the TZ, precluding sensory cilia assembly, and no ciliary membrane cap associated with sperm ciliogenesis is made. This ciliary cap is critical to recruit the tubulin-depolymerizing kinesin Klp59D, required for regulation of axonemal growth. Our results show that Drosophila TZ assembly in sensory neurons and male germ cells involves cooperative actions of Cby and Dila. They further reveal that temporal control of membrane cap assembly by TZ components and microtubule elongation by kinesin-13 is required for axoneme formation in male germ cells.

Prevalence of Oral and Maxillofacial Trauma in Elders Admitted to a Reference Hospital in Northeastern Brazil.

OBJECTIVE: To know the prevalence and etiology of oral and maxillofacial trauma in elders. METHODS: Analytical quantitative cross-sectional study conducted at a public trauma hospital located in Fortaleza-Ceará, Brazil. The study population comprised patients with trauma who were hospitalized from April to August 2014. Of these patients, patients with oral and maxillofacial trauma were chosen to be included in the research. A questionnaire was administered in order to obtain information on socio-demographics, systemic comorbidities, use of medication, deleterious habits (smoking and alcohol consumption), etiology of oral and maxillofacial trauma and type of pre-hospital care. RESULTS: Of the 280 elderly hospitalized with trauma, 47 had oral and maxillofacial trauma, with a prevalence of 16.8%. In this group, the age ranged from 60 to 88 years, with a mean age of 72.4 years (SD± 8.38). The elderly were mostly women (55.3%), self-declared pardos (53.2%), who presented with cardiovascular disorders (48.9%), and who received formal pre-hospital care (70.2%). Elderly who were in the 60-69 years age group, spent 6-9 years at school and drank alcohol were 2.64, 3.75, and 1.97, respectively, more likely to suffer oral and maxillofacial trauma. The main causes of trauma were physical aggression, traffic accidents, falls and domestic accidents. All of the physical aggressions resulted in oral and maxillofacial traumas, and the elderly who suffered traffic accidents were four times more likely to have oral and maxillofacial trauma. CONCLUSION: The prevalence of 16.8% and the lack of research on oral and maxillofacial traumas in the elderly is worrisome and should be included in the oral health indicators for the elderly population to support the importance of oral health.

Galvanic deposition of Rh and Ru on randomly structured Ti felts for the electrochemical NH3 synthesis.

Nowadays NH3 is exclusively synthesized by the Haber process. Unfortunately, the energy demand and the CO2 emissions due to H2 production are high. Hydrogen production utilizes precious carbon sources such as coal and natural gas. In the past we proposed an alternative process concept using a membrane electrode assembly in an electrochemical membrane reactor (ecMR). At the anode H2O is oxidized at an IrMMO catalyst to form protons. By applying an external potential to the ecMR N2 is reduced to NH3 at the cathode. Just recently Rh and Ru were identified as possible cathodic electrocatalysts by DFT calculations. We present an easy and highly efficient method for galvanic coatings of Rh and Ru on randomly structured Ti felts to be used in a membrane electrode assembly. Linear sweep voltammetry measurements give a slightly higher activity of Ru for the liquid phase electrochemical NH3 synthesis. The NH4(+) concentration reached is 8 times higher for Ru than for Rh. From an economical point of view, Ru is also more feasible for an electrochemical NH3 synthesis process. Such electrodes can now be evaluated in an ecMR in comparison to recently demonstrated Ti-based electrodes.

Cometary science. Birth of a comet magnetosphere: a spring of water ions.

The Rosetta mission shall accompany comet 67P/Churyumov-Gerasimenko from a heliocentric distance of >3.6 astronomical units through perihelion passage at 1.25 astronomical units, spanning low and maximum activity levels. Initially, the solar wind permeates the thin comet atmosphere formed from sublimation, until the size and plasma pressure of the ionized atmosphere define its boundaries: A magnetosphere is born. Using the Rosetta Plasma Consortium ion composition analyzer, we trace the evolution from the first detection of water ions to when the atmosphere begins repelling the solar wind (~3.3 astronomical units), and we report the spatial structure of this early interaction. The near-comet water population comprises accelerated ions (<800 electron volts), produced upstream of Rosetta, and lower energy locally produced ions; we estimate the fluxes of both ion species and energetic neutral atoms.

A link between hepatic glucose production and peripheral energy metabolism via hepatokines.

Type 2 diabetes is characterized by a deterioration of glucose tolerance, which associates insulin resistance of glucose uptake by peripheral tissues and increased endogenous glucose production. Here we report that the specific suppression of hepatic glucose production positively modulates whole-body glucose and energy metabolism. We used mice deficient in liver glucose-6 phosphatase that is mandatory for endogenous glucose production. When they were fed a high fat/high sucrose diet, they resisted the development of diabetes and obesity due to the activation of peripheral glucose metabolism and thermogenesis. This was linked to the secretion of hepatic hormones like fibroblast growth factor 21 and angiopoietin-like factor 6. Interestingly, the deletion of hepatic glucose-6 phosphatase in previously obese and insulin-resistant mice resulted in the rapid restoration of glucose and body weight controls. Therefore, hepatic glucose production is an essential lever for the control of whole-body energy metabolism during the development of obesity and diabetes.

Modification of energy balance induced by the food contaminant T-2 toxin: a multimodal gut-to-brain connection.

T-2 toxin is one of the most toxic Fusarium-derived trichothecenes found on cereals and constitutes a widespread contaminant of agricultural commodities as well as commercial foods. Low doses toxicity is characterized by reduced weight gain. To date, the mechanisms by which this mycotoxin profoundly modifies feeding behavior remain poorly understood and more broadly the effects of T-2 toxin on the central nervous system (CNS) have received limited attention. Through an extensive characterization of sickness-like behavior induced by T-2 toxin, we showed that its per os (p.o.) administration affects not only feeding behavior but also energy expenditure, glycaemia, body temperature and locomotor activity. Using c-Fos expression mapping, we identified the neuronal structures activated in response to T-2 toxin and observed that the pattern of neuronal populations activated by this toxin resembled that induced by inflammatory signals. Interestingly, part of neuronal pathways activated by the toxin were NUCB-2/nesfatin-1 expressing neurons. Unexpectedly, while T-2 toxin induced a strong peripheral inflammation, the brain exhibited limited inflammatory response at a time point when anorexia was ongoing. Unilateral vagotomy partly reduced T-2 toxin-induced brainstem neuronal activation. On the other hand, intracerebroventricular (icv) T-2 toxin injection resulted in a rapid (<1h) reduction in food intake. Thus, we hypothesized that T-2 toxin could signal to the brain through neuronal and/or humoral pathways. The present work provides the first demonstration that T-2 toxin modifies feeding behavior by interfering with central neuronal networks devoted to central energy balance. Our results, with a particular attention to peripheral inflammation, strongly suggest that inflammatory mediators partake in the T-2 toxin-induced anorexia and other symptoms. In view of the broad human and breeding animal exposure to T-2 toxin, this new mechanism may lead to reconsider the impact of the consumption of this toxin on human health.

Gastric distension activates NUCB2/nesfatin-1-expressing neurons in the nucleus of the solitary tract.

Brainstem structures such as the nucleus of the solitary tract (NTS) and the dorsal motor nucleus of the vagus nerve (DMNX) are essential for the digestive function of the stomach. A large number of neurotransmitters including glutamate and gamma-aminobutyric acid (GABA) are involved in the central control of gastric functions. However, the neuropeptidergic systems implicated in this process remain undetermined. Nesfatin-1 was recently identified as a neuropeptide cleaved from the N-terminal part of NEFA/nucleobindin 2 precursor (NUCB2). Central administration of this neuropeptide inhibits food consumption and gastroduodenal motility in rodents. Interestingly, the NTS and the DMNX contain a dense population of NUCB2/nesfatin-1 cell bodies. These observations led us to investigate the possible involvement of NUCB2/nesfatin-1 neurons in the brainstem neuronal pathways that modulate gastric functions. We observed an activation of NTS NUCB2/nesfatinergic neurons after gastric distention in rats. In addition, we found that several NTS NUCB2/nesfatinergic neurons were GABAergic. Finally, when fluorogold was injected at the stomach level, many retrogradely labeled neurons were observed in the DMNX which were also positive for NUCB2/nesfatin-1. Taken together, these observations suggest for the first time that NUCB2/nesfatin-1 neurons of the NTS are sensitive to gastric distension and then may contribute to the satiety signal.