Mapping conditioned taste aversion associations using c-Fos reveals a dynamic role for insular cortex
Ming Teng Koh1, Ilene L Bernstein
1Department of Psychology, University of Washington, Seattle, WA 98195-1525, USA.
Insights
Novel tastes enhance taste aversion learning more than familiar ones, recruiting a larger neural circuit. The insular cortex (IC) plays a dual role in detecting novelty and forming safe taste memories.
Area of Science:
- Neuroscience
- Behavioral Neuroscience
- Learning and Memory
Background:
- Novel tastes are more effective conditioned stimuli (CSs) in taste aversion learning compared to familiar tastes.
- Novel CS-unconditioned stimulus (US) pairings elicit stronger Fos-like immunoreactivity (FLI) in the insular cortex (IC), amygdala, and brainstem than familiar pairings, indicating broader neural recruitment for novel taste acquisition.
Purpose of the Study:
- To elucidate the specific role of the insular cortex (IC) in taste aversion learning, particularly concerning novelty detection and memory formation.
- To differentiate the functions of the IC in the acquisition of novel taste aversion versus the consolidation of familiar taste safety.
Main Methods:
- Immunostaining was combined with targeted lesions or reversible inactivation of the insular cortex (IC).
- Fos-like immunoreactivity (FLI) was measured in the IC, amygdala, and brainstem following novel and familiar taste-US pairings.
- Taste preexposure followed by reversible inactivation was used to assess the formation of 'safe' taste memories.
Main Results:
- IC lesions abolished FLI increases in the amygdala during novel taste pairings, suggesting a role for the IC in novelty detection.
- Reversible inactivation of the IC during taste preexposure led to increased FLI in the amygdala and brainstem during familiar taste pairings.
- Temporary inactivation disrupted the establishment of 'safe' taste memory, unlike permanent lesions.
Conclusions:
- The insular cortex (IC) plays a critical, dual role in taste learning: it is essential for novelty detection during acquisition and involved in forming memories of safe tastes.
- These findings highlight the complex neural circuitry underlying taste aversion learning and the specific contributions of the IC to different phases of the learning process.
Abstract:
Novel tastes are more effective than familiar tastes as conditioned stimuli (CSs) in taste aversion learning. Parallel to this, a novel CS-unconditioned stimulus (US) pairing induced stronger Fos-like immunoreactivity (FLI) in insular cortex (IC), amygdala, and brainstem than familiar CS-US pairing, suggesting a large circuit is recruited for acquisition. To better define the role of IC, the authors combined immunostaining with lesion or reversible inactivation of IC. Lesions abolished FLI increases to novel taste pairing in amygdala, suggesting a role in novelty detection. Reversible inactivation during taste preexposure increased FLI to familiar taste pairing in amygdala and brainstem. The difference between temporary inactivation, which blocked establishment of "safe" taste memory, and lesions points to a dual role for IC in taste learning.
Related Concept Videos
Gustation
Olfaction
The olfactory receptors are embedded in the cilia of the...
Somatosensation
Association Areas of the Cortex
Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,...
Somatosensory, Motor, and Association Cortex
Conditioned Taste Aversion
A notable characteristic of conditioned taste aversion is that it often requires only a single exposure...


