Savings and extinction of conditioned eyeblink responses in fragile X syndrome

Albertine Smit, Jos van der Geest, M Vellema, Bas Koekkoek, Rob Willemsen, LCP Govaerts, Ben Oostra, Chris de Zeeuw, Frans Werf

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The fragile X syndrome (FRAXA) is the most widespread heritable form of mental retardation caused by the lack of expression of the fragile X mental retardation protein (FMRP). This lack has been related to deficits in cerebellum-mediated acquisition of conditioned eyelid responses in individuals with FRAXA. In the present behavioral study, long-term effects of deficiency of FMRP were investigated by examining the acquisition, savings and extinction of delay eyeblink conditioning in male individuals with FRAXA. In the acquisition experiment, subjects with FRAXA displayed a significantly poor performance compared with controls. In the savings experiment performed at least 6 months later, subjects with FRAXA and controls showed similar levels of savings of conditioned responses. Subsequently, extinction was faster in subjects with FRAXA than in controls. These findings confirm that absence of the FMRP affects cerebellar motor learning. The normal performance in the savings experiment and aberrant performance in the acquisition and extinction experiments of individuals with FRAXA suggest that different mechanisms underlie acquisition, savings and extinction of cerebellar motor learning.
Original languageUndefined/Unknown
Pages (from-to)770-777
Number of pages8
JournalGenes Brain and Behavior
Issue number7
Publication statusPublished - 2008

Research programs

  • EMC MGC-02-96-01
  • EMC ONWAR-01-94-01

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