First Author | Bureau I | Year | 2008 |
Journal | J Neurosci | Volume | 28 |
Issue | 20 | Pages | 5178-88 |
PubMed ID | 18480274 | Mgi Jnum | J:136321 |
Mgi Id | MGI:3795990 | Doi | 10.1523/JNEUROSCI.1076-08.2008 |
Citation | Bureau I, et al. (2008) Circuit and plasticity defects in the developing somatosensory cortex of FMR1 knock-out mice. J Neurosci 28(20):5178-88 |
abstractText | Silencing of the Fmr1 gene causes fragile X syndrome. Although defects in synaptic plasticity in the cerebral cortex have been linked to cognitive impairments in Fmr1 knock-out (ko) mice, the specific cortical circuits affected in the syndrome are unknown. Here, we investigated the development of excitatory projections in the barrel cortex of Fmr1 ko mice. In 2-week-old Fmr1 ko mice, a major ascending projection connecting layer 4 (L4) to L3 (L4-->L3), was defective in multiple and independent ways: its strength was reduced, caused by a lower connection probability; the axonal arbors of L4 cells were spatially diffuse in L2/3; the L4-->L3 projection did not show experience-dependent plasticity. By 3 weeks, the strength of the L4-->L3 projection was similar to that of wild type. Our data indicate that Fmr1 shapes sensory cortical circuits during a developmental critical period. |