Activity Based Anorexia as an Animal Model for Anorexia Nervosa–A Systematic Review

Anorexia nervosa (AN) is a severe eating disorder affecting around 1 per 100 persons. However, the knowledge about its underlying pathophysiology is limited. To address the need for a better understanding of AN, an animal model was established early on in the late 1960's: the activity-based anorexia (ABA) model in which rats have access to a running wheel combined with restricted food access leading to self-starving/body weight loss and hyperactivity. Both symptoms, separately or combined, can also be found in patients with AN. The aim of this systematic review was to compile the current knowledge about this animal model as well as to address gaps in knowledge. Using the data bases of PubMed, Embase and Web of science 102 publications were identified meeting the search criteria. Here, we show that the ABA model mimics core features of human AN and has been characterized with regards to brain alterations, hormonal changes as well as adaptations of the immune system. Moreover, pharmacological interventions in ABA animals and new developments, such as a chronic adaptation of the ABA model, will be highlighted. The chronic model might be well suited to display AN characteristics but should be further characterized. Lastly, limitations of the model will be discussed

The role of peptides in the pathogenesis of depression and anxiety – implication of NUCB2/nesfatin-1

Background: Depressive and anxiety disorders are highly prevalent diseases causing distinct loss of quality of life. Their pathogenesis is poorly understood and thus currently available treatment options are associated with notable side effects, significant therapy resistance and high relapse rates. Consequently, there is a need for better understanding of their etiology and the present work aims to investigate the role of peptides in their development. Methods: Therefore, using male Sprague Dawley rats (I) the effect of the active fragment of nesfatin-1 on depressive-like and anxious behavior was examined in several test paradigms, followed (II) by the same investigations in diet-induced obese rats. Additionally, (III) using a nesfatin-1 antibody the endogenous role of nesfatin-1 in depressive-like and anxious behavior was tested under naïve and stress conditions. Finally, since depression and anxiety are closely related to the hypothalamic-pituitary-adrenal axis, (IV) the effect of emotional stress on circulating nesfatin-1 levels was tested. Results: It could be shown that (I) intracerebroventricularly injected 0.3 nmol nesfatin-130-59 increased anhedonia reflecting depressive-like behavior, as well as anxiety in normal weight, (II) but not in diet-induced obese rats. Furthermore, (III) an endogenous role of nesfatin-1 in the mediation of anxiety but not in depressiveness could be demonstrated by reduced anxious behavior in nesfatin-1 antibody-treated naïve normal weight rats. In stressed rats acute nesfatin-1 blockade elicited no effect; however, (IV) an increased circulating level of NUCB2/nesfatin-1 was observed after 240 minutes of immobilization. Conclusion: The present studies showed that nesfatin-1, whose circulating levels are upregulated by stress, is differentially implicated in the development of depression and anxiety. While it induces anhedonia only after exogenous injection, endogenous nesfatin-1 affects anxiety and acts supposedly up-stream from corticotropin-releasing factor signaling. This hypothesis, however, warrants further research.Hintergrund: Depressive Störungen und Angststörungen sind hochprävalente Krankheitsbilder, die mit einer deutlichen Einschränkung der Lebensqualität einhergehen. Ihre Pathogenese ist nur unzureichend geklärt und so sind die derzeit verfügbaren Behandlungsmöglichkeiten mit erheblichen Nebenwirkungen, häufigen Therapieresistenzen und hohen Rückfallraten verbunden. Daher besteht ein Bedarf für ein besseres Verständnis ihrer Ätiologie und die vorliegende Arbeit zielt darauf ab, die Rolle von Peptiden bei ihrer Entstehung zu untersuchen. Methoden: Hierzu wurde bei männlichen Sprague Dawley Ratten (I) die Wirkung des aktiven Fragments von Nesfatin-1 auf depressives und ängstliches Verhalten in verschiedenen Testparadigmen untersucht, gefolgt von (II) den gleichen Untersuchungen bei adipösen Ratten. Zusätzlich wurde (III) unter Verwendung eines Nesfatin-1-Antikörpers die endogene Rolle von Nesfatin-1 an depressivem und ängstlichem Verhalten bei naiven Tieren sowie unter Stressbedingungen beleuchtet. Da Depression und Angst eng mit der Stress-Achse assoziiert sind, wurde schließlich (IV) der Effekt von psychischem Stress auf die zirkulierenden NUCB2/Nesfatin-1-Spiegel untersucht. Ergebnisse: Es konnte gezeigt werden, dass (I) intrazerebroventrikulär injiziertes Nesfatin-130-59 (0,3 nmol) Anhedonie, als eine Form von depressivem Verhalten, sowie Angst bei normalgewichtigen, aber (II) nicht bei adipösen Ratten induzierte. Darüber hinaus konnte (III) eine endogene Rolle von Nesfatin-1 bei der Vermittlung von Angst, aber nicht von depressivem Verhalten nachgewiesen werden, welche durch geringer ausgeprägtes Angstverhalten bei mit Nesfatin-1-Antikörper behandelten naiven normalgewichtigen Ratten demonstriert wurde. Bei gestressten Ratten löste eine akute Nesfatin-1-Blockade keinen Effekt aus, jedoch wurde (IV) ein erhöhter zirkulierender Spiegel von NUCB2/Nesfatin-1 nach 240-minütiger Immobilisation beobachtet. Schlussfolgerung: Die vorliegende Studie zeigte, dass Nesfatin-1, dessen zirkulierende Spiegel durch Stress erhöht waren, in unterschiedlicher Weise an der Entstehung von Depressivität und Ängstlichkeit beteiligt ist. Während Nesfatin-1 Anhedonie nur nach exogener Injektion induzierte, beeinflusst es Ängstlichkeit über exogene und endogene Mechanismen, die vermutlich dem Corticotropin-Releasing-Faktor-Signalweg vorgeschaltet sind. Diese Hypothese bedarf jedoch weiterer Forschung

Phoenixin—A pleiotropic gut-brain peptide

Phoenixin is a recently discovered brain peptide initially thought to be restricted to reproductive functions. The subsequent identification of phoenixin's expression in peripheral tissues was accompanied by the description of several other actions of this hormone, such as effects on behavior, sensory perception, memory retention, the cardiovascular system as well as food intake, pointing towards a pleiotropic role of this peptide. The present review will discuss the present knowledge on phoenixin and the signaling involved as well as highlight gaps in knowledge to stimulate further research

Coherent Pion Production by Neutrinos

In this talk I review the main features of the coherent/diffractive pion production by neutrinos on nuclei. The method is based on PCAC and relates the reaction $\textbf{boson} + \textbf{nucleus} \to \textbf{pion} + \textbf{nucleus}$ to elastic pion-nucleus scattering. Estimates for the expected rates and distributions in neutrino reactions are presented with the help of hadronic data. The absolute rates are significantly smaller than the older estimates which brings theory in agreement with the neutral current measurements and the bounds in charged current reactions.Comment: 5 pages, 7 figures, Proceedings of the Sixth International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt09), May 18-22, Sitges, Barcelona, Spai

Some problems of the thin film cadmium sulfide solar cell

Storage, humidity, thermal cycling, and mechanism of thin film cadmium sulfide solar cell