Abstract #0140
Endogenous GABA Concentration and Haemodynamic Responses to Graded Visual Contrast
Mark Mikkelsen 1 , C. John Evans 1 , Alan J. Stone 1,2 , Esther A. H. Warnert 1 , and Krish D. Singh 1
1
CUBRIC, School of Psychology, Cardiff
University, Cardiff, United Kingdom,
2
FMRIB,
Nuffield Department of Clinical Neurosciences,
University of Oxford, Oxford, United Kingdom
Concentration of the neurotransmitter γ-aminobutyric
acid (GABA) is known to predict task-related BOLD and
CBF responses. Here, we simultaneously measured BOLD and
CBF in the visual cortex whilst employing a graded
visual contrast paradigm to investigate GABAs potential
association with properties of haemodynamic contrast
tuning. GABA levels were non-invasively measured with 1H
MRS. Rate of response saturation was inversely related
to GABA concentration such that participants with higher
GABA levels had faster BOLD response saturation to
contrast. GABA concentration is associated with
individual differences in haemodynamic contrast tuning
and may be a mediator of the dynamic range of BOLD/CBF
responses.
This abstract and the presentation materials are available to members only;
a login is required.
Join Here
