| Autor: |
Conde V; Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiolgía Clínica, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, Seville, Spain., Palomar FJ, Lama MJ, Martínez R, Carrillo F, Pintado E, Mir P |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of neurophysiology [J Neurophysiol] 2013 Mar; Vol. 109 (5), pp. 1315-22. Date of Electronic Publication: 2012 Dec 12. |
| DOI: |
10.1152/jn.00730.2012 |
| Abstrakt: |
The fragile X syndrome is a mutation-driven developmental disorder caused by a repetition over 200 times of the CGG trinucleotide situated in the 5'-untranslated region of the fragile X mental retardation 1 gene (FMR1). The interval between 55 and 199 CGG repeats, which is over the normal range but below full mutation, is named fragile X premutation. Recent studies have focused on the asymptomatic state of fragile X premutation carriers and their potentially relevant preclinical features. However, the underlying neurological mechanisms leading to altered functions in fragile X premutation carriers are still poorly understood. In this study, we wanted to test the hypothesis that asymptomatic women who carry the fragile X premutation present GABAergic and cerebellar abnormalities compared with healthy women without the premutation. We performed noninvasive brain stimulation protocols on both asymptomatic fragile X premutation carriers and controls comprising of measures of GABAA- and GABAB-mediated intracortical inhibition, afferent inhibition, and cerebello-motor functional interactions. Premutation carriers presented an absence of cerebellar inhibition over primary motor cortex as well as a reduced GABAA-mediated intracortical and afferent inhibition compared with healthy nonpremutated controls. These alterations are most probably dependent on a dysfunctional GABAergic mechanism associated with the fragile X premutation condition as previously found in CGG-repeat animal models. Furthermore, the lack of cerebello-motor inhibition could be related to the cerebellar structural abnormalities previously found in carriers of the premutation. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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