Mechanisms of circulatory homeostasis and response in Aplysia.

This review concerns the organization and function of arterial vasculature in Aplysia californica, especially the vasomotor reflexes that support circulatory homeostasis, and fixed patterns of response that may reroute blood flow during changes in behavioral state. The observations presented here raise three hypotheses for further study: 1) Arterial vasculature is functionally organized with precisely structured, independently regulated subdivisions; these are most evident for arterial systems serving digestive and reproductive processes; 2) arterial musculature is inherently responsive to local pressure changes, having both static and dynamic reflexes that promote efficient, evenly-distributed flow of blood; and 3) complex, long-lasting behaviors like egg laying have, as part of their makeup, equally prolonged and stereotypical changes in the pattern of circulation. Taken together, these observations support the view that maintenance and adjustment of blood flow in gastropod molluscs is an unexpectedly complex and highly integrated component of behavior.     

Mechanisms of circulatory homeostasis and response inAplysia

This review concerns the organization and function of arterial vasculature inAplysia californica, especially the vasomotor reflexes that support circulatory homeostasis, and fixed patterns of response that may reroute blood flow during changes in behavioral state. The observations presented here raise three hypotheses for further study: 1)Arterial vasculature is functionally organized with precisely structured, independently regulated subdivisions; these are most evident for arterial systems serving digestive and reproductive processes; 2) arterial musculature is inherently responsive to local pressure changes, having both static and dynamic reflexes that promote efficient, evenly-distributed flow of blood; and 3) complex, long-lasting behaviors like egg laying have, as part of their makeup, equally prolonged and stereotypical changes in the pattern of circulation. Taken together, these observations support the view that maintenance and adjustment of blood flow in gastropod molluscs is an unexpectedly complex and highly integrated component of behavior.     

Isotope scanning of subdural effusions in infancy

Zusammenfassung Die Methode der Scintigraphie der subduralen Effusion mit dem I¹³¹-Hippuran wird dargestellt. Bei der Subduralpunktion wird die abgelassene Subduralflüssigkeit durch 1–4 µC I¹³¹-Hippuran ersetzt. Mit dieser Isotopenscintigraphie ist es möglich, die horizontale Projektion der subduralen Effusion und die Stellen der sagittalen Naht sowie der grossen Fontanelle in normaler Grösse im Scintigramm zu registrieren.

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Aided by a grant from the University of Oulu.     

Primary cilia elongation in response to interleukin-1 mediates the inflammatory response

Primary cilia are singular, cytoskeletal organelles present in the majority of mammalian cell types where they function as coordinating centres for mechanotransduction, Wnt and hedgehog signalling. The length of the primary cilium is proposed to modulate cilia function, governed in part by the activity of intraflagellar transport (IFT). In articular cartilage, primary cilia length is increased and hedgehog signaling activated in osteoarthritis (OA). Here, we examine primary cilia length with exposure to the quintessential inflammatory cytokine interleukin-1 (IL-1), which is up-regulated in OA. We then test the hypothesis that the cilium is involved in mediating the downstream inflammatory response. Primary chondrocytes treated with IL-1 exhibited a 50% increase in cilia length after 3 h exposure. IL-1-induced cilia elongation was also observed in human fibroblasts. In chondrocytes, this elongation occurred via a protein kinase A (PKA)-dependent mechanism. G-protein coupled adenylate cyclase also regulated the length of chondrocyte primary cilia but not downstream of IL-1. Chondrocytes treated with IL-1 exhibit a characteristic increase in the release of the inflammatory chemokines, nitric oxide and prostaglandin E2. However, in cells with a mutation in IFT88 whereby the cilia structure is lost, this response to IL-1 was significantly attenuated and, in the case of nitric oxide, completely abolished. Inhibition of IL-1-induced cilia elongation by PKA inhibition also attenuated the chemokine response. These results suggest that cilia assembly regulates the response to inflammatory cytokines. Therefore, the cilia proteome may provide a novel therapeutic target for the treatment of inflammatory pathologies, including OA.     

Pressor response to oxotremorine in atropinized rats

Zusammenfassung Eine zentrale, nikotinartige Wirkung von Oxotremorin wird am Blutdruck der Ratte beschreiben.     

Feeding response of adultTribolium to carbohydrates in relation to their utilisation

Zusammenfassung Die Fütterungsreaktionen beim erwachsenenTribolium castaneum (Herbst.) zeigen, dass keine der verschiedenen Kohlenhydrate das Fressen besonders anregt. Der Nährwert dieser Kohlenhydrate nimmt in folgender Reihenfolge ab: Stärke und Maltose; Glukose, Melibiose und Milchzucker; Rohrzucker, Fruchtzucker, Melezitose, Raffinose und Cellobiose.     

Mechanisms of flight steering in locusts

Summary Steering in flight by locusts provides a well-studied example of the modulation of a rhythmic motor output by unpredictable inputs from outside to produce adaptive behaviour, in this case a form of locomotion. The simplest form, correctional steering, allows the animal to compensate for unintentional deviations from course. Its mechanisms are relatively well understood. The central nervous circuitry which makes this behaviour possible can be thought of as an autopilot. The entire process, from sensory input to the aerodynamic effects of changed motor outputs, is here reviewed. Intentional change of course, either spontaneous or induced by a change in the outside world, is more complex: it demands not only active steering, but also the temporary disablement of the autopilot. The mechanisms by which this could be achieved are discussed.     

Mechanisms of self-incompatibility in flowering plants

Self-incompatibility is a widespread mechanism in flowering plants that prevents inbreeding and promotes outcrossing. The self-incompatibility response is genetically controlled by one or more multi-allelic loci, and relies on a series of complex cellular interactions between the self-incompatible pollen and pistil. Although self-incompatibility functions ultimately to prevent self-fertilization, flowering plants have evolved several unique mechanisms for rejecting the self-incompatible pollen. The self-incompatibility system in the Solanaceae makes use of a multi-allelic RNase in the pistil to block incompatible pollen tube growth. In contrast, the Papaveraceae system appears to have complex cellular responses such as calcium fluxes, actin rearrangements, and programmed cell death occurring in the incompatible pollen tube. Finally, the Brassicaceae system has a receptor kinase signalling pathway activated in the pistil leading to pollen rejection. This review highlights the recent advances made towards understanding the cellular mechanisms involved in these self-incompatibility systems and discusses the striking differences between these systems. Received 10 May 2001; received after revision 20 June 2001; accepted 20 June 2001     

Erythropoietic response to isomeres of triiodothyronine

Zusammenfassung Verabreichung vond-, wie auch vonl-Triiodothyrosin erzeugt eine ähnliche Vermehrung der Erythropoiesis in nephroektomierten Ratten, wie bei der Messung der Radioeiseninkorporation durch Erythrozyten (18 h nach Injektion von radioaktivem Eisencitrat). Es ergab sich weiter, dassd- undl-Thyrosin, im Unterschied zu Erythropoieten, die reticulozytose Eisenassimilation in vitro vermehrte. Danach scheinen verschiedene Mechanismen bei der Stimulation der Erythropoiesis durch Erythropoieten und Triiodothyronin im Spiele zu sein.     

Brain response to calorie restriction

Calorie restriction extends longevity and delays ageing in model organisms and mammals, opposing the onset and progression of an array of age-related diseases. These beneficial effects also extend to the maintenance of brain cognitive functions at later age and to the prevention, at least in rodents, of brain senescence and associated neurodegenerative disorders. In recent years, the molecular mechanisms underlying brain response to calorie restriction have begun to be elucidated, revealing the unanticipated role of a number of key nutrient sensors and nutrient-triggered signaling cascades in the translation of metabolic cues into cellular and molecular events that ultimately lead to increased cell resistance to stress, enhanced synaptic plasticity, and improved cognitive performance. Of note, the brain’s role in CR also includes the activation of nutrient-sensitive hypothalamic circuitries and the implementation of neuroendocrine responses that impact the entire organism. The present review addresses emerging molecular themes in brain response to dietary restriction, and the implications of this knowledge for the understanding and the prevention of brain disorders associated with ageing and metabolic disease.     

Moth visual potentials in response to middle UV-radiation

Zusammenfassung Das dunkeladaptierte Facettenauge vom NachtschmetterlingManduca sexta wurde mit UV-Licht mittlerer Wellenlänge (2700–3100 Å) bei niedriger Intensität bestrahlt. Der photorezeptorische Anteil des ERGs war vermindert oder verschwunden, aber nachsynaptische Wirkungen wurden beobachtet. Impulsaktivitäten wurden bei einem hauptsächlich efferenten Flugmuskelnerv ausgelöst, wenn das kontralaterale Auge beleuchtet wurde.

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This research was supported in part by a USDA-ERD research grant No. 12-14-100-7742 (33).