Retrieval of conditioned immune response in male mice is mediated by an anterior-posterior insula circuit.

To protect the body from infections, the brain has evolved the ability to coordinate behavioral and immunological responses. The conditioned immune response (CIR) is a form of Pavlovian conditioning wherein a sensory (for example, taste) stimulus, when paired with an immunomodulatory agent, evokes aversive behavior and an anticipatory immune response after re-experiencing the taste. Although taste and its valence are represented in the anterior insular cortex and immune response in the posterior insula and although the insula is pivotal for CIRs, the precise circuitry underlying CIRs remains unknown.

Intrinsic Excitability in Layer IV-VI Anterior Insula to Basolateral Amygdala Projection Neurons Correlates with the Confidence of Taste Valence Encoding.

Avoiding potentially harmful, and consuming safe food is crucial for the survival of living organisms. However, the perceived valence of sensory information can change following conflicting experiences. Pleasurability and aversiveness are two crucial parameters defining the perceived valence of a taste and can be impacted by novelty.

Insula to mPFC reciprocal connectivity differentially underlies novel taste neophobic response and learning in mice.

To survive in an ever-changing environment, animals must detect and learn salient information. The anterior insular cortex (aIC) and medial prefrontal cortex (mPFC) are heavily implicated in salience and novelty processing, and specifically, the processing of taste sensory information. Here, we examined the role of aIC-mPFC reciprocal connectivity in novel taste neophobia and memory formation, in mice.

Parvalbumin interneuron inhibition onto anterior insula neurons projecting to the basolateral amygdala drives aversive taste memory retrieval.

Memory retrieval refers to the fundamental ability of organisms to make use of acquired, sometimes inconsistent, information about the world. Although memory acquisition has been studied extensively, the neurobiological mechanisms underlying memory retrieval remain largely unknown. Conditioned taste aversion (CTA) is a robust associative paradigm, through which animals can be trained to express aversion toward innately appetitive tastants.

eIF2α controls memory consolidation via excitatory and somatostatin neurons.

An important tenet of learning and memory is the notion of a molecular switch that promotes the formation of long-term memory. The regulation of proteostasis is a critical and rate-limiting step in the consolidation of new memories. One of the most effective and prevalent ways to enhance memory is by regulating the synthesis of proteins controlled by the translation initiation factor eIF2.

Activity of Insula to Basolateral Amygdala Projecting Neurons is Necessary and Sufficient for Taste Valence Representation.

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.

The Insula and Taste Learning.

The sense of taste is a key component of the sensory machinery, enabling the evaluation of both the safety as well as forming associations regarding the nutritional value of ingestible substances. Indicative of the salience of the modality, taste conditioning can be achieved in rodents upon a single pairing of a tastant with a chemical stimulus inducing malaise. This robust associative learning paradigm has been heavily linked with activity within the insular cortex (IC), among other regions, such as the amygdala and medial prefrontal cortex.