title: In vivo γ-aminobutyric acid measurement in rats with spectral editing at 4.7T.
abstract: To evaluate the feasibility of spectral editing for quantification of γ-aminobutyric acid (GABA) in the rat brain and to determine whether altered GABA concentration in the ventral striatum is a neural endophenotype associated with trait-like impulsive behavior.
  
  
  
  Spectra were acquired at 4.7T for 23 male Lister-hooded rats that had been previously screened for extremely low and high impulsivity phenotypes on an automated behavioral task (n = 11 low-impulsive; n = 12 high-impulsive). Voxels of 3 × 7 × 4 mm(3) (84 μL) centered bilaterally across the ventral striatum were used to evaluate GABA concentration ratios.
  
  
  
  Quantifiable GABA signals in the ventral striatum were obtained for all rats. Mean-edited GABA to n-acetyl aspartate (NAA) ratios in the ventral striatum were 0.22 (95% confidence interval [CI] [0.18, 0.25]). Mean GABA/NAA ratios in this region were significantly decreased by 28% in high-impulsive rats compared to low-impulsive rats (P = 0.02; 95% CI [-53%, -2%]).
  
  
  
  These findings demonstrate that spectral editing at 4.7T is a feasible method to assess in vivo GABA concentrations in the rat brain. The results show that diminished GABA content in the ventral striatum may be a neural endophenotype associated with impulsivity. J. Magn. Reson. Imaging 2016;43:1308-1312.
authors.affiliation: Behavioural and Clinical Neuroscience Institute, University of Cambridge, UK.|Wolfson Brain Imaging Centre, University of Cambridge, UK.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Sawiak
authors.affiliation: Behavioural and Clinical Neuroscience Institute, University of Cambridge, UK.
authors.forename: Bianca
authors.initials: B
authors.lastname: Jupp
authors.affiliation: Cavendish Laboratory, University of Cambridge, UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Taylor
authors.affiliation: Behavioural and Clinical Neuroscience Institute, University of Cambridge, UK.
authors.forename: Daniele
authors.initials: D
authors.lastname: Caprioli
authors.affiliation: Wolfson Brain Imaging Centre, University of Cambridge, UK.
authors.forename: T Adrian
authors.initials: TA
authors.lastname: Carpenter
authors.affiliation: Behavioural and Clinical Neuroscience Institute, University of Cambridge, UK.|Department of Psychology, University of Cambridge, UK.|Department of Psychiatry, University of Cambridge, UK.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Dalley
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D057054:Molecular Imaging / Q000379:methods*; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D005680:gamma-Aminobutyric Acid
keywords: GABA; behavior; nucleus accumbens; spectroscopy; striatum