The evaluation of brain activity in response to taste stimuli - A pilot study and method for central taste activation as assessed by event-related fMRI

Background: Brain pathways contribute to the regulation of appetite behaviors, and advancements in brain imaging offer new opportunities in determining whether disturbances of these pathways play a role in pathological feeding behaviors in humans. We developed a standardized method for the assessment of brain activation in response to taste stimuli. Methods: Five healthy control women were positioned in a 1.5T GE magnet resonance (MR) scanner for functional MR imaging (fMRI). They received 1.0cm³ samples of 1M glucose solution or artificial saliva (25mM KCl, 2mM NaHCO ₃). Fluid challenges were delivered by a programmable syringe pump (J-Kem Scientific, St. Louis, MO). E-Prime software (Psychology Software Tools Inc., Pittsburgh, PA) coordinated taste stimulation with MR scanning. Data were analyzed using NeuroImaging software (NIS). Results: Healthy women showed increased orbitofrontal cortex activation when glucose was compared to artificial saliva. In addition, mesial and lateral temporal cortical regions contrasted glucose from artificial saliva. Conclusions: This study demonstrates a design for the systematic study of brain activation after taste stimulation using fMRI and computer controlled stimulus delivery. The results are consistent with previous studies, showing activation in higher order brain centers that are involved in emotional coding of taste experience.