Sucrose intensity coding and decision-making in rat gustatory cortices

Elife. 2018 Nov 19;7:e41152. doi: 10.7554/eLife.41152.

Abstract

Sucrose's sweet intensity is one attribute contributing to the overconsumption of high-energy palatable foods. However, it is not known how sucrose intensity is encoded and used to make perceptual decisions by neurons in taste-sensitive cortices. We trained rats in a sucrose intensity discrimination task and found that sucrose evoked a widespread response in neurons recorded in posterior-Insula (pIC), anterior-Insula (aIC), and Orbitofrontal cortex (OFC). Remarkably, only a few Intensity-selective neurons conveyed the most information about sucrose's intensity, indicating that for sweetness the gustatory system uses a compact and distributed code. Sucrose intensity was encoded in both firing-rates and spike-timing. The pIC, aIC, and OFC neurons tracked movement direction, with OFC neurons yielding the most robust response. aIC and OFC neurons encoded the subject's choices, whereas all three regions tracked reward omission. Overall, these multimodal areas provide a neural representation of perceived sucrose intensity, and of task-related information underlying perceptual decision-making.

Keywords: decision-variables; neuroscience; obesity; rat; reward; taste Intensity; taste coding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Animals
  • Cerebral Cortex / drug effects*
  • Cerebral Cortex / physiology
  • Decision Making / drug effects*
  • Neurons / drug effects
  • Neurons / physiology
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / physiology
  • Rats
  • Sucrose / administration & dosage*
  • Sucrose / chemistry
  • Taste / drug effects
  • Taste / physiology*

Substances

  • Sucrose

Grant support

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.