Gustatory evoked potentials activity and fatty taste

Introduction: Gustatory evoked potentials (GEP), detected in response to an intermittent stimulation of the gustatory receptors by a primary flavor, are a reliable and safe record of the human gustatory function. We previously highlighted the modifications of GEP in response to saccharose stimulation by the concentration of the saccharose solution and its hedonic sensation. Fatty taste might be considered as the sixth primary flavor. We aimed to demonstrate that GEP in response to fatty taste stimulation do exist, and to compare these GEP with the GEP in response to saccharose and salty taste. Methods: Healthy and voluntary male subjects were included. Each subject underwent six GEP recording with different taste solutions: 5g and 20g of saccharose per 100mL of water, 0,5g and 2g of NaCl per 100mL of water, 0.25% and 1% linoleic acid solution. GEP were recorded from 9 cortical sites with EEG sensors: Cz, Fz, Pz, C3, C4, F3, F4, Fp1 and Fp2 of the 10/20 system. Results:We already included 12 subjects. We recorded GEP in response to the two concentrations of linoleic acid, like as saccharose and salt stimuli. GEP in response to saccharose stimulation had shorter latency and higher amplitude than fatty or salty taste. Contrary to salty and fatty stimulation, saccharose solution strongly activated the bilateral orbito-frontal cortex. Discussion/Conclusion:Recording GEP in response to linoleic acid stimulation shows that it exists gustative receptors which response to fatty taste. So, it is a strong argument to say that fatty taste can be considered as the sixth primary flavor.