Conditioned taste aversion (CTA) is an associative learning paradigm, wherein consumption of an appetitive tastant (e.g., saccharin) is paired to the administration of a malaise-inducing agent, such as intraperitoneal injection of LiCl. Aversive taste learning and retrieval require neuronal activity within the anterior insula (aIC) and the basolateral amygdala (BLA). Here, we labeled neurons of the aIC projecting to the BLA in adult male mice using a retro-AAV construct and assessed their necessity in aversive and appetitive taste learning. By restricting the expression of chemogenetic receptors in aIC-to-BLA neurons, we demonstrate that activity within the aICto-BLA projection is necessary for both aversive taste memory acquisition and retrieval, but not for its maintenance, nor its extinction. Moreover, inhibition of the projection did not affect incidental taste learning per se, but effectively suppressed aversive taste memory retrieval when applied either during or beforethe encoding ofthe unconditioned stimulus for CTA (i.e., malaise). Remarkably, activation ofthe projection after noveltaste consumption, without experiencing any internal discomfort, was sufficienttoform an artificial aversive taste memory, resulting in strong aversive behavior upon retrieval. Our results indicate that aIC-to-BLA projecting neurons are an essential component in the ability of the brain to associate taste sensory stimuli with body states of negative valence and guide the expression of valence-specific behavior upon taste memory retrieval.
Bibliographical noteFunding Information:
This work was supported by a grant from the Canadian Institutes of Health Research (CIHR), the International Development Research Centre (IDRC), the Israel Science Foundation (ISF), and the Azrieli Foundation (ISF-IDRC 2395/2015); ISF 946/17; ISF-UGC 2311/15; and ChromISyn ERANET Neuron II supported by the Israel Ministry of HealthGrant3-12492toK.R.H.K.isarecipientoftheEdmonddeRothschild’sscholarship.Wethankthemembersof the K.R. laboratory, specifically Dr. Shunit Gal Ben-Ari, for critical reading of this manuscript. The authors declare no competing financial interests. *H.K. and A.Y. contributed equally to this work.
© 2019 Society for Neuroscience. All rights reserved.
- Brain Circuits
- Taste Learning
- Valence Encoding
ASJC Scopus subject areas
- Neuroscience (all)