title: Deficits in tactile learning in a mouse model of fragile X syndrome.
abstract: The fragile X mental retardation 1 mutant mouse (Fmr1 KO) recapitulates several of the neurologic deficits associated with Fragile X syndrome (FXS). As tactile hypersensitivity is a hallmark of FXS, we examined the sensory representation of individual whiskers in somatosensory barrel cortex of Fmr1 KO and wild-type (WT) mice and compared their performance in a whisker-dependent learning paradigm, the gap cross assay. Fmr1 KO mice exhibited elevated responses to stimulation of individual whiskers as measured by optical imaging of intrinsic signals. In the gap cross task, initial performance of Fmr1 KO mice was indistinguishable from WT controls. However, while WT mice improved significantly with experience at all gap distances, Fmr1 KO mice displayed significant and specific deficits in improvement at longer distances which rely solely on tactile information from whiskers. Thus, Fmr1 KO mice possess altered cortical responses to sensory input that correlates with a deficit in tactile learning.
authors.affiliation: Developmental Neuroscience Program, Saban Research Institute, Children's Hospital Los Angeles, Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Megan T
authors.initials: MT
authors.lastname: Arnett
authors.affiliation: Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America.
authors.forename: David H
authors.initials: DH
authors.lastname: Herman
authors.affiliation: Developmental Neuroscience Program, Saban Research Institute, Children's Hospital Los Angeles, Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Aaron W
authors.initials: AW
authors.lastname: McGee
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics; D005600:Fragile X Syndrome / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D055698:Touch Perception / Q000235:genetics / Q000502:physiology*
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1