| First Author | Ivanco TL | Year | 2002 |
| Journal | Hippocampus | Volume | 12 |
| Issue | 1 | Pages | 47-54 |
| PubMed ID | 11918288 | Mgi Jnum | J:113177 |
| Mgi Id | MGI:3664705 | Doi | 10.1002/hipo.10004 |
| Citation | Ivanco TL, et al. (2002) Altered mossy fiber distributions in adult Fmr1 (FVB) knockout mice. Hippocampus 12(1):47-54 |
| abstractText | The fragile-X mental retardation protein (FMRP) is greatly reduced or absent in individuals with fragile-X mental retardation syndrome, a common, heritable form of mental retardation. Morphological studies suggest that this protein functions in normal synapse maturation and neuronal plasticity. Examination of human brain autopsy tissue has shown that fragile-X patients exhibit long, thin spines more frequently, and stubby mushroom-shaped spines less frequently, than these two types of spines are seen in normal autopsy tissue. Fragile-X tissue also has a greater density of these spines along dendrites, which suggests a possible failure of synapse elimination. Fmr1 knockout mice and wild-type littermates brains were processed for Timm staining, which reveals the zinc-rich terminals of the dentate gyrus, the mossy fibers. The Fmr1 knockout mice exhibited a pattern of Timm granule-staining within the stratum oriens of subfield CA3 and the inner molecular layer that was significantly different than staining seen in wild-type animals. The sources and consequences of the altered terminal staining are unclear, but are discussed in relation to immature synapse morphology, a failure of normal regression of synapses, and a potential biological penalty of such a failure to regress. |
