Conditional corticotropin-releasing hormone overexpression in the mouse forebrain enhances rapid eye movement sleep

Impaired sleep and enhanced stress hormone secretion are the hallmarks of stress-related disorders, including major depression. The central neuropeptide, corticotropin-releasing hormone (CRH), is a key hormone that regulates humoral and behavioral adaptation to stress. Its prolonged hypersecretion is believed to play a key role in the development and course of depressive symptoms, and is associated with sleep impairment. To investigate the specific effects of central CRH overexpression on sleep, we used conditional mouse mutants that overexpress CRH in the entire central nervous system (CRH-COE-Nes) or only in the forebrain, including limbic structures (CRH-COE-Cam). Compared with wild-type or control mice during baseline, both homozygous CRH-COE-Nes and -Cam mice showed constantly increased rapid eye movement (REM) sleep, whereas slightly suppressed non-REM sleep was detected only in CRH-COE-Nes mice during the light period. In response to 6-h sleep deprivation, elevated levels of REM sleep also became evident in heterozygous CRH-COE-Nes and -Cam mice during recovery, which was reversed by treatment with a CRH receptor type 1 (CRHR1) antagonist in heterozygous and homozygous CRH-COE-Nes mice. The peripheral stress hormone levels were not elevated at baseline, and even after sleep deprivation they were indistinguishable across genotypes. As the stress axis was not altered, sleep changes, in particular enhanced REM sleep, occurring in these models are most likely induced by the forebrain CRH through the activation of CRHR1. CRH hypersecretion in the forebrain seems to drive REM sleep, supporting the notion that enhanced REM sleep may serve as biomarker for clinical conditions associated with enhanced CRH secretion

International collaborative learning with the case-based online learning-platform ICON

In this project the interactive online learning platform ICON was used as a vehicle to explore the research question in which way a cooperative use of virtual cases within an interactive learning platform affects the learning process and dynamic in mixed student groups from the US and Germany. The ICON platform allows students to interact with each other, faculty and virtual patients in neurological cases. Students of Harvard University and the University of Witten worked in the winter semester 2009 in two mixed groups. The students from the different universities communicated via the ICON platform and created diagnostic hypotheses, and treatment proposals. As a result the international student group collaboration showed a positive effect regarding the efficiency and accuracy of students achievement of case learning objectives.Im Rahmen des Projektes sollte erforscht werden, inwieweit sich eine kooperative Nutzung von virtuellen Fällen in einer interaktiven Lernplattform durch Studenten aus Deutschland und den USA auf Lerneffektivität und Dynamik der Gruppenarbeit auswirkt. Die onlinebasierte Lernplattform ICON ermöglicht es, Fälle online in Gruppen zu bearbeiten und dabei mit diversen Experten zu kommunizieren und den Fall je nach dem Lernbedarf der Teilnehmer im Dialog dynamisch weiterzuentwickeln. Studenten der Harvard University und der Universität Witten haben im Wintersemester 2009 online in zwei gemischten Gruppen mittels der interaktiven und nutzerzentrierten Online-Lernplattform ICON Fallgeschichten bearbeitet und entwickelten gemeinsam diagnostische Hypothesen und Therapievorschläge. Es konnte ein positiver Einfluss auf den Lernprozess, die Problemlösungskompetenz und Entscheidungsfindung nachgewiesen werden

Sleep-Dependent Changes in the Coupling Between Heart Period and Arterial Pressure in Newborn Lambs

This study assessed whether sleep-dependent changes in the relationship between heart period (HP) and mean arterial pressure (MAP) occur in newborn life. Electrodes for electrocorticographic, electromyographic, and electrooculographic monitoring and an arterial catheter for blood pressure recordings were implanted in 11 newborn lambs. HP and MAP beat-to-beat values were computed from 120-s blood pressure recordings during quiet wakefulness, active sleep, and quiet sleep. For each recording, the time shift at which the maximum of the HP versus MAP cross-correlation function was attained was identified. For each lamb and wake-sleep state, an average correlation coefficient was then computed corresponding to the median value of such time shifts. The maximum of the cross-correlation function was attained with HP lagging behind MAP. The corresponding mean correlation coefficient was significantly higher in quiet sleep (0.51 ± 0.05) than either in quiet wakefulness (0.31 ± 0.05) or in active sleep (0.29 ± 0.03). Sleep-related differences in the correlation between HP and MAP were maintained after HP and MAP data were low-pass filtered at 0.3 Hz to remove their fast ventilatory oscillations. In conclusion, data indicate that the relationship between spontaneous fluctuations in HP and those in MAP is sleep-state dependent in newborn lambs. A positive HP versus MAP correlation with HP lagging behind MAP is consistent with baroreflex control of HP. Heart rhythm thus may be more tightly controlled by the baroreceptor reflex and less dependent on central autonomic commands in quiet sleep than either in quiet wakefulness or in active sleep

Uncertainty Challenge in Geospatial Analysis: An Approximation from the Land Use Cover Change Modelling Perspective

All data and geospatial analyses come with uncertainty. Although its importance has been widely recognized, uncertainty issues are still not correctly addressed in most of the current geospatial research. This chapter aims to provide an overview of the concepts, sources and tools to manage the uncertainty in geospatial analysis. To this end, we intend to increase the awareness about the importance of uncertainty for all geospatial data and analyses. Due to time and chapter length considerations, we address this topic from the Land Use Cover Change Modelling perspective.Agencia Estatal de InvestigaciónDepto. de GeografíaFac. de Geografía e HistoriaTRUEpu