Cortical representation of different taste modalities on the gustatory cortex: A pilot study

Area of Science:

• Neuroscience
• Sensory Perception
• Gustatory System

Background:

• The right insular cortex plays a role in taste discrimination, but its functional organization remains unclear.
• Sensory cortices typically exhibit ordered spatial representations of features.
• This study investigates if the primary taste cortex is organized similarly for six basic tastes.

Purpose of the Study:

• To investigate the functional organization of the primary taste cortex.
• To map the spatial representation of six tastes (sweet, bitter, sour, salt, umami, CO2) in the right insular cortex.
• To test the hypothesis of an ordered representation of taste features.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used in ten healthy subjects.
• High-resolution cortical registration and feature prevalence localization techniques were employed.
• Responses to six taste solutions (bitter, sweet, salt, umami, sour, CO2) were mapped in the right insular cortex.

Main Results:

• Statistically significant fMRI activations were observed for all tastes in the right insular cortex.
• Taste prevalence mapping revealed two segregated clusters: one for sweet-bitter and another for salt-umami-sour tastes.
• Carbon dioxide (CO2) taste was represented between these two clusters.

Conclusions:

• The primary taste cortex exhibits a spatially organized representation of taste features.
• This organization appears to serve an ecological function, enhancing discrimination between safe nutrients and harmful substances.