TABLE 6

Effect of long-term benzodiazepine treatment in vivo on GABAA receptor subunit polypeptide expression

Compound, Species, Dose, Duration, Brain RegionSubunit mRNAReference
α1α2α5β2β3γ2
% change
Diazepam
    Rat, 3×5 to 3×20 mg/kg/d, 14 dImpagnatiello et al., 1996
        Frontoparietal motor cortex−37+158+47β2/3+50
        Frontoparietal somatosensory cortexN.S.+209N.S.β2/3N.S.
    Rat, 3×5 to 3×20 mg/kg/d, 14 dPesold et al., 1997
        Frontoparietal motor cortex−37LIII-IVN.S.+150+48β2/3+48
        Frontoparietal somatosensory cortexN.S.N.S.+221N.S.β2/3N.S.
Flurazepam
    Rat, 100 mg/kg/day, 7 dChen et al., 1999
        Hippocampus
            CA1−20N.S.N.S.−19N.S.
            CA2N.S.N.S.N.S.−25SRN.S.
            CA3−38N.S.N.S.−14SLN.S.
            Dentate gyrus−34N.S.N.S.−18−8ML
        Cerebral cortex
            Layer IN.S.N.S.N.S.
            Layer II/III−24Fr−23Fr,ParN.S.
            Layer IV−26Par−20ParN.S.
            Layer V−19Fr,Occ−42FrN.S.
            Layer VI−23−38FrN.S.
        Caudate-putamen—N.S.—N.S.N.S.
        ThalamusN.S.—N.S.—N.S.
        Substantia nigra reticulataN.S.—N.S.—N.S.
        Inferior colliculusN.S.—N.S.—N.S.
        Superior colliculus—N.S.—N.S.N.S.
        CerebellumN.S.—N.S.N.S.N.S.
Imidazenil
    Rat, 3×1 to 3×4 mg/kg/d, 14 dImpagnatiello et al., 1996
        Frontoparietal motor cortexN.S.N.S.N.S.β2/3N.S.
        Frontoparietal somatosensory cortexN.S.N.S.N.S.β2/3N.S.
Rat, 3×1 to 3×4 mg/kg/d, 14 dPesold et al., 1997
        Frontoparietal motor cortexN.S.N.S.N.S.N.S.β2/3N.S.
        Frontoparietal somatosensory cortexN.S.−22LIII-IVN.S.N.S.β2/3N.S.

  • d, day(s); N.S., not significantly different from the control value; —, not detected; β2/3, detected using an antibody specific to β2 and β3 subunits; LIII-IV, layers III and IV; SR, stratum radiatum; SL, stratum lacunosum; ML, molecular layer; Fr, frontal; Par, parietal; Occ, occipital.