Talampanel reduces the level of motoneuronal calcium in transgenic mutant SOD1 mice only if applied presymptomatically

We tested the efficacy of treatment with talampanel in a mutant SOD1 mouse model of ALS by measuring intracellular calcium levels and loss of spinal motor neurons. We intended to mimic the clinical study; hence, treatment was started when the clinical symptoms were already present. The data were compared with the results of similar treatment started at a presymptomatic stage. Transgenic and wild-type mice were treated either with talampanel or with vehicle, starting in pre-symptomatic or symptomatic stages. The density of motor neurons was determined by the physical disector, and their intracellular calcium level was assayed electron microscopically. Results showed that motor neurons in the SOD1 mice exhibited an elevated calcium level, which could be reduced, but not restored, with talampanel only when the treatment was started presymptomatically. Treatment in either presymptomatic or symptomatic stages failed to rescue the motor neurons. We conclude that talampanel reduces motoneuronal calcium in a mouse model of ALS, but its efficacy declines as the disease progresses, suggesting that medication initiation in the earlier stages of the disease might be more effective

Rodent Models of TDP-43 Proteinopathy: Investigating the Mechanisms of TDP-43-Mediated Neurodegeneration

Since the identification of phosphorylated and truncated transactive response DNA-binding protein 43 (TDP-43) as a primary component of ubiquitinated inclusions in amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions, much effort has been directed towards ascertaining how TDP-43 contributes to the pathogenesis of disease. As with other protein misfolding disorders, TDP-43-mediated neuronal death is likely caused by both a toxic gain and loss of TDP-43 function. Indeed, the presence of cytoplasmic TDP-43 inclusions is associated with loss of nuclear TDP-43. Moreover, post-translational modifications of TDP-43, including phosphorylation, ubiquitination, and cleavage into C-terminal fragments, may bestow toxic properties upon TDP-43 and cause TDP-43 dysfunction. However, the exact neurotoxic TDP-43 species remain unclear, as do the mechanism(s) by which they cause neurotoxicity. Additionally, given our incomplete understanding of the roles of TDP-43, both in the nucleus and the cytoplasm, it is difficult to truly appreciate the detrimental consequences of aberrant TDP-43 function. The development of TDP-43 transgenic animal models is expected to narrow these gaps in our knowledge. The aim of this review is to highlight the key findings emerging from TDP-43 transgenic animal models and the insight they provide into the mechanisms driving TDP-43-mediated neurodegeneration

Groups, organizations, families and movements: The sociology of social systems between interaction and society

Kühl S. Groups, organizations, families and movements: The sociology of social systems between interaction and society. Systems Research and Behavioral Science. 2020;37(3):496-515.In enhancing a proposal by Luhmann, this contribution shows that it is possible to locate different types of systems between ‘face‐to‐face‐interaction’ and ‘society’: groups, organizations, families and protest movements. The common ground of these is that they use membership to attribute persons to the system or not. However, they differ fundamentally in regard to how they understand membership. In contrast to Luhmann's differentiation between interaction, organization and society, it is not only possible to imagine different types of interlocking systems but also coequal combinations of and transitions between the different types of social systems