Alterations of the cortico-cortical network in sensori-motor areas of dystrophin deficient mice.
The dystrophin defective mdx mouse, acknowledged model of Duchenne Muscular Dystrophy (DMD), bears outstanding alterations of the cortical architecture, that could be responsible for the cognitive impairment often accompanying this pathological condition. Using a retrograde tract tracing technique to label neurons in Golgi-like fashion, we investigated the fine anatomical organization of associative cortico-cortical projections in mdx mice. While the absolute number of associative pyramidal neurons was significantly higher in mdx than in control animals, the ratio between the number of supra- and infragranular cortico-cortical cells was substantially unmodified. Basal dendrites of layer 2/3 pyramidal neurons displayed longer terminal branches in mdx compared to controls. Finally, the density of dendritic spines was significantly lower in mdx animals. The anomalies of associative cortico-cortical projections provide potential groundwork on the neurobiological bases of cognitive involvement in DMD and value the role of cortical microcircuitry alterations as possible source of interference with peripheral motor impairment.
Minciacchi
D
D
Department of Physiology, University of Florence, Florence, Italy. diego@unifi.it
Del Tongo
C
C
Carretta
D
D
Nosi
D
D
Granato
A
A
D000818:Animals; D001710:Biotin / Q000031:analogs & derivatives; D002452:Cell Count; D048430:Cell Shape / Q000502:physiology; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D003072:Cognition Disorders / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D003712:Dendrites / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D049229:Dendritic Spines / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D003911:Dextrans; D004195:Disease Models, Animal; D016189:Dystrophin / Q000172:deficiency* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D009044:Motor Cortex / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D020388:Muscular Dystrophy, Duchenne / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D009415:Nerve Net / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D056325:Neuronal Tract-Tracers; D017966:Pyramidal Cells / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D013003:Somatosensory Cortex / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D013194:Staining and Labeling
D003911:Dextrans; D016189:Dystrophin; D056325:Neuronal Tract-Tracers; C076397:biotinylated dextran amine; D001710:Biotin