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Mueller, H.-P.

Publications and source records attributed to Mueller, H.-P..

2 recordsLinked to original sources
bioRxiv2020

Disruption of orbitofrontal-hypothalamic projections in a murine ALS model and human patients

Increased catabolism is a new clinical manifestation of Amyotrophic Lateral Sclerosis. A dysfunction of lateral hypothalamus may drive hypermetabolism in ALS; however, Its causes and anatomical substrates are unknown. We hypothesize that disruption cortico-hypothalamic circuits may impair energy homeostasis in ALS. We used rAAV2 for large-scale projection mapping and image analysis pipeline based on Wholebrain and Ilastik to quantify projections from the forebrain to the latera hypothalamus of the SOD1(G93A) ALS mouse model as well as of the Fus{Delta}NLS ALS mouse model. Expanded projections from agranular Insula, ventrolateral orbitofrontal and secondary motor cortex to lateral hypothalamus were found in two independent cohorts of the hypermetabolic SOD1(G93A) ALS model. The non-hypermetabolic Fus{Delta}NLS ALS mouse model display a loss of projections from motor cortex but no change in projections from insula and orbitofronal cortex. 3T DTI-MRI data on 83 ALS patients and 65 controls confirmed the disruption of the orbitofrontal-hypothalamic tract in ALS patients. Converging murine and human data demonstrate the selective disruption of hypothalamic inputs in ALS as a factor contributing to the origin of hypermetabolism. Significance statementWe provide a circuit perspective of the recently identified and medically relevant hyper-metabolic phenotype of Amyotrophic Lateral Sclerosis. We demonstrate the selective involvement of orbitofrontal, insular and motor cortex projections to hypothalamus in murine ALS models and in human patients. The enhanced pipeline for large-scale registration, segmentation projections mapping, the identification of new circuits target of neurodegeneration, and the relevance of these circuits in metabolic disturbances make this work relevant not only for the investigation of ALS but also for other neurodegenerative disease as well as for all conditions characterized by systemic energy imbalances.

neuroscience↗
bioRxiv2020

Cytoplasmic accumulation of FUS triggers early behavioral alterations linked to cortical neuronal hyperactivity and defects in inhibitory synapses

Gene mutations causing cytoplasmic mislocalization of the RNA-binding protein FUS, lead to severe forms of amyotrophic lateral sclerosis (ALS). Cytoplasmic accumulation of FUS is also observed in other diseases, with unknown consequences. Here, we show that cytoplasmic mislocalization of FUS drives behavioral abnormalities in knock-in mice, including locomotor hyperactivity and alterations in social interactions, in the absence of widespread neuronal loss. Mechanistically, we identified a profound increase in neuronal activity in the frontal cortex of Fus knock-in mice in vivo. Importantly, RNAseq analysis suggested involvement of defects in inhibitory neurons, that was confirmed by ultrastructural and morphological defects of inhibitory synapses and increased synaptosomal levels of mRNAs involved in inhibitory neurotransmission. Thus, cytoplasmic FUS triggers inhibitory synaptic deficits, leading to increased neuronal activity and behavioral phenotypes. FUS mislocalization may trigger deleterious phenotypes beyond motor neuron impairment in ALS, but also in other neurodegenerative diseases with FUS mislocalization.

neuroscience↗