Double-blind, placebo-controlled, multiple-ascending-dose study on the pharmacodynamics of ABIO-08/01, a new CNS drug with potential anxiolytic activity. 2. EEG-tomography findings based on LORETA (low-resolution brain electromagnetic tomography)

Neuropsychobiology. 2009;59(2):110-22. doi: 10.1159/000212380. Epub 2009 Apr 10.


Effects of ABIO-08/01, a new potentially anxiolytic isoxazoline, on regional electrical brain generators were investigated by 3-dimensional EEG tomography. In a double- blind, placebo-controlled, multiple-ascending-dose study, 16 healthy males (30.2 +/- 5.7 years) received 3 oral drug doses (10, 20, 40 mg) and placebo for 7 days (8-day wash-out) in a randomized non-balanced design for phase-1 studies. A 3-min vigilance-controlled (V) EEG, a 4-min resting (R) EEG with eyes closed, a 1-min eyes-open (EO) EEG and psychometric tests were performed 0, 1 and 6 h after taking the drug on days 1 and 5. Low-resolution brain electromagnetic tomography (LORETA) was computed from the spectrally analyzed EEG data, and differences between drug and placebo were displayed as statistical parametric maps. Data were registered to the Talairach-Tournoux Human Brain Atlas available as a digitized MRI. An overall omnibus significance test followed by a voxel-by-voxel t test demonstrated significant regional EEG changes after ABIO-08/01 versus placebo, dependent on recording condition, dose and time. While in the EO-EEG specifically the lowest dose of ABIO-08/01 induced pronounced sedative effects (delta/theta and beta increase) 1 h after acute and slightly less so after superimposed administration, in the 6th hour a decrease in alpha and beta activity signaled less sedative and more relaxant action. In the V-EEG these changes were less pronounced, in the R-EEG partly opposite. Hemisphere-specific changes were observed, suggesting increases in LORETA power over the left temporal, parietal, superior frontal regions and decreases over the right prefrontal, temporal pole and occipital regions. These LORETA changes are discussed in the light of neuroimaging findings on anxiety and anxiolytics.

Publication types

  • Clinical Trial, Phase I
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Anti-Anxiety Agents / pharmacology*
  • Brain Mapping
  • Cerebral Cortex / drug effects*
  • Cerebral Cortex / physiology
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Electroencephalography / drug effects*
  • Hippocampus / drug effects*
  • Hippocampus / physiology
  • Humans
  • Isoxazoles / pharmacology*
  • Male
  • Placebos
  • Psychomotor Performance / drug effects
  • Time Factors
  • Tomography / methods*


  • ABIO 0801
  • Anti-Anxiety Agents
  • Isoxazoles
  • Placebos