Developmental Profile of the Aberrant Dopamine D2 Receptor Response in Striatal Cholinergic Interneurons in DYT1 DystoniaReportar como inadecuado




Developmental Profile of the Aberrant Dopamine D2 Receptor Response in Striatal Cholinergic Interneurons in DYT1 Dystonia - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Background

DYT1 dystonia, a severe form of genetically determined human dystonia, exhibits reduced penetrance among carriers and begins usually during adolescence. The reasons for such age dependence and variability remain unclear.

Methods and Results

We characterized the alterations in D2 dopamine receptor D2R signalling in striatal cholinergic interneurons at different ages in mice overexpressing human mutant torsinA hMT. An abnormal excitatory response to the D2R agonist quinpirole was recorded at postnatal day 14, consisting of a membrane depolarization coupled to an increase in spiking frequency, and persisted unchanged at 3 and 9 months in hMT mice, compared to mice expressing wild-type human torsinA and non-transgenic mice. This response was blocked by the D2R antagonist sulpiride and depended upon G-proteins, as it was prevented by intrapipette GDP-β-S. Patch-clamp recordings from dissociated interneurons revealed a significant increase in the Cav2.2-mediated current fraction at all ages examined. Consistently, chelation of intracellular calcium abolished the paradoxical response to quinpirole. Finally, no gross morphological changes were observed during development.

Conclusions

These results suggest that an imbalanced striatal dopaminergic-cholinergic signaling occurs early in DYT1 dystonia and persists along development, representing a susceptibility factor for symptom generation.



Autor: Giuseppe Sciamanna, Annalisa Tassone, Giuseppina Martella, Georgia Mandolesi, Francesca Puglisi, Dario Cuomo, Grazia Madeo, Giuli

Fuente: http://plos.srce.hr/



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