2024 Theses Doctoral

Experience dependent shaping of cortical taste representation

Lawen, Amir

Characterizing the cortical representation of sweet and bitter tastes in awake behaving mice has been challenging due to the sheltered location of the gustatory cortex in the insula, which restricts optical and electrophysiological recordings, and the various functions of the insula, complicating conclusions about taste representation.

To overcome these obstacles, we developed a brain-wide imaging paradigm that combines functional magnetic resonance imaging (fMRI) with optogenetic and taste receptor knock-out manipulations in mice. This approach allowed us the study the gustatopic map in awake, behaving mice, showing that sweet and bitter tastes are topographically segregated along the rostro-caudal axis of the gustatory cortex, with sweet represented rostrally and bitter caudally. Notably, this map is subject to plasticity following conditioned taste aversion (CTA) for sweet stimuli, resulting in a posterior shift of the sweet taste field—a phenomenon reversible after CTA extinction.