A gustocentric perspective to understanding primary sensory cortices

Abstract

Most of the general principles used to explain sensory cortical function have been inferred from experiments performed on neocortical, primary sensory areas. Attempts to apply a neocortical view to the study of the gustatory cortex (GC) have provided only a limited understanding of this area. Failures to conform GC to classical neocortical principles have been implicitly interpreted as a demonstration of GC's uniqueness. Here we propose to take the opposite perspective, dismissing GC's uniqueness and using principles extracted from its study as a lens for looking at neocortical sensory function. In this review, we describe three significant findings related to gustatory cortical function and advocate their relevance for understanding neocortical sensory areas.

Multisensory and Motor Representations in Rat Oral Somatosensory Cortex

“…Samuelsen and Fontanini (2017) demonstrated that these cortical neurons can integrate chemosensory stimuli by responding exclusively to tastants and odorants or the combination of both 13 . These findings suggest that the gustatory cortex encodes information in a dynamic, distributed and multimodal manner 12 – 14 .…”

“…A separate line of work has demonstrated that gustatory cortex neurons can display taste-specific responses that vary as a function of time since stimulus delivery 8 and that taste-specific information can be encoded by the coordinated activity of neuron pairs 9 . The gustatory cortex can also encode non-gustatory stimuli like tactile, thermal and olfactory information during the consumption of food 10 – 12 . Samuelsen and Fontanini (2017) demonstrated that these cortical neurons can integrate chemosensory stimuli by responding exclusively to tastants and odorants or the combination of both 13 .…”

Mapping the sequence of brain events in response to disgusting food

“…The insula with surrounding frontal cortex are the best candidates to account for disgust awareness as a bodily sensation typically implying unpleasant feelings in the oral cavity and abdomen [Nummenmaa et al, ]. The primary gustatory cortex is precisely located in the anterior insula and frontal operculum [Scott and Plata‐Salamán, ], for both palatable and aversive (disgusting) gustatory stimulation [Vincis and Fontanini, ]. Hunger is another oral and abdominal sensation with a cortical representation in the anterior insula and surrounding frontal cortex [Dagher, ].…”

Synaptic Integration of Thalamic and Limbic Inputs in Rodent Gustatory Cortex

“…Sensory perception depends on the integration of sensory and affective features of stimuli, yet how these properties are encoded and processed by cortical neurons is not well understood. The primary gustatory cortex (GC) provides a unique model for investigating this question, as GC neurons in alert animals multiplex sensory, affective, and associative signals (Maffei et al, 2012;Vincis and Fontanini, 2016b). Indeed, GC neurons encode information about the physiochemical identity and hedonic value of tastants, along with anticipatory activity, in the temporal dynamics of their spiking responses (Yamamoto et al, 1981(Yamamoto et al, , 1984aKatz et al, 2001;Pritchard and Norgren, 2004;Spector and Travers, 2005;Fontanini and Katz, 2006;Yokota et al, 2007;Grossman et al, 2008;Piette et al, 2012;Sadacca et al, 2012Sadacca et al, , 2016Samuelsen et al, 2012Samuelsen et al, , 2013Jezzini et al, 2013;Maier and Katz, 2013;Gardner and Fontanini, 2014;Moran and Katz, 2014;Vincis and Fontanini, 2016a).…”