Mitochondrial metabolism in hypoglossal motoneurons from mouse – implications for amyotrophic lateral sclerosis (ALS)
Mitochondrialer Metabolismus in hypoglossalen Motoneuronen der Maus - Bedeutung für die Amyotrophe Lateral Sklerose (ALS)
by Friederike Bergmann
Date of Examination:2004-02-12
Date of issue:2004-03-03
Advisor:Prof. Dr. Bernhard Keller
Referee:Prof. Dr. Bernhard Keller
Referee:Prof. Dr. Walter Paulus
Referee:Prof. Dr. Erwin Neher
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Description:Dissertation
Abstract
English
Motoneurons (MNs) are selectively damaged both in human amyotrophic lateral sclerosis (ALS) and corresponding mouse models of this neurodegenerative disease. A variety of studies indicate that mitochondrial dysfunction and disruption of the cellular Ca2+ homeostasis represent critical events during the disease process. Since little is known about the involvement of mitochondria in regulation of Ca2+ levels in MNs, the first aim of this work was to define the contribution of mitochondria to the clearance of physiological type Ca2+ loads. Second, the work aimed at characterizing the cellular consequences of mitochondrial dysfunction in MNs, with particular attention to changes in electrical properties and alterations in Ca2+ homeostasis, as this may give clues to the understanding of processes involved in MN degeneration and the selective vulnerability of MNs in ALS. The contribution of mitochondria to buffering of Ca2+ loads was investigated employing acute mouse brainstem slices containing the hypoglossal motor nucleus and CCD camera based imaging techniques. It was demonstrated that in hypoglossal MNs, mitochondria constitute the dominant Ca2+ clearance mechanism accounting for buffering of ~50 % of voltage activated Ca2+ loads with amplitudes below 0.4
Keywords: motoneuron; mitochondria; calcium; neurodegeneration; ALS; hypoxia; hypoglossal
Schlagwörter: Motoneuron; Mitochondrien; Kalzium; Neurodegeneration; ALS; Hypoxie; Hypoglossus; 570 Biowissenschaften; Biologie