Neuromuscular synapse degeneration without muscle function loss in the diaphragm of a murine model for Huntington's Disease

Publication date: June 2018 Source:Neurochemistry International, Volume 116 Author(s): Priscila A.C. Valadão, Matheus P.S.M. Gomes, Bárbara C. Aragão, Hermann A. Rodrigues, Jéssica N. Andrade, Rubens Garcias, Julliane V. Joviano-Santos, Murilo A. Luiz, Wallace L. Camargo, Lígia A. Naves, Christopher Kushmerick, Walter L.G. Cavalcante, Márcia Gallacci, Itamar C.G. de Jesus, Silvia Guatimosim, Cristina Guatimosim Huntington's disease (HD) is an autosomal dominant neurodegenerative disease characterized by chorea, incoordination and psychiatric and behavioral symptoms. The leading cause of death in HD patients is aspiration pneumonia, associated with respiratory dysfunction, decreased respiratory muscle strength and dysphagia. Although most of the motor symptoms are derived from alterations in the central nervous system, some might be associated with changes in the components of motor units (MU). To explore this hypothesis, we evaluated morphofunctional aspects of the diaphragm muscle in a mouse model for HD (BACHD). We showed that the axons of the phrenic nerves were not affected in 12-months-old BACHD mice, but the axon terminals that form the neuromuscular junctions (NMJs) were more fragmented in these animals in comparison with the wild-type mice. In BACHD mice, the synaptic vesicles of the diaphragm NMJs presented a decreased exocytosis rate. Quantal content and quantal size were smaller and there was less synaptic depression whereas the estimated si...
Source: Neurochemistry International - Category: Neuroscience Source Type: research