Impaired sensorimotor gating in Fmr1 knock out and Fragile X premutation model mice

Area of Science:

• Neurogenetics
• Neurodegenerative Diseases
• Molecular Biology

Background:

• Fragile X syndrome (FXS) stems from CGG repeat expansion in the FMR1 gene, causing intellectual disability.
• Fragile X-associated Tremor/Ataxia Syndrome (FXTAS) is linked to FMR1 premutations, leading to neurodegeneration.
• Sensorimotor gating deficits, measured by pre-pulse inhibition (PPI), are observed in both FXS and FXTAS.

Purpose of the Study:

• To investigate sensorimotor gating (PPI) in FMR1 CGG knock-in (KI) mice, a model for FXTAS.
• To compare PPI deficits in FMR1 knock-out (KO) and CGG KI mice.
• To establish a novel phenotype in CGG KI mice for therapeutic development.

Main Methods:

• Utilized a quiet pre-pulse inhibition (PPI) protocol, mimicking human testing conditions.
• Assessed PPI in FMR1 knock-out (KO) mice.
• Evaluated PPI in CGG knock-in (KI) mice across different ages and compared them to wild-type (WT) controls.

Main Results:

• FMR1 KO mice exhibited significantly impaired PPI.
• CGG KI mice demonstrated an age-dependent impairment in PPI compared to WT controls.
• This study identified a novel phenotype in CGG KI mice relevant to FXTAS.

Conclusions:

• FMR1 KO mice show significant sensorimotor gating deficits.
• CGG KI mice display an age-dependent PPI impairment, mirroring FXTAS symptoms.
• The CGG KI mouse model offers a valuable tool for studying and developing therapies for FXTAS.