How a taste memory is waiting hours for visceral information to form conditioned taste aversion? The 21st Annual Meeting of the Israel Society for Neuroscience & The First Binational Australian-Israeli Meeting in Neuroscience

The innate reluctance to eat novel taste, gustatory neophobia, is one of the most important behaviors that prevent animals from ingesting large quantity of a new and possibly toxic food. The consumption of a novel taste that is not associated with negative visceral consequences leads to the formation of a non-associative form of sensory memory, known as incidental taste memory. Conditioned taste aversion (CTA) is an associative learning in which animals learn to avoid a novel taste (CS) associated with delayed poisoning (US). In contrast to other forms of associative learning, CTA can be established with CS-US intervals measured in hours. It is unknown how a memory of given taste is waiting the visceral consequence for such long delay. We hypothesized that kinase activity or kinases activity loops underlie this form of lingering memory. In order to test our hypothesis we first examined carefully the temporal limitation of the association. Our behavioral results in rats show that CTA can be established with the CS-US intervals of up to 8 hours. In addition, there is a negative correlation of aversive taste memory with the CS-US interval: the greater the CS-US interval, the weaker the CTA conditioning. Immunoblotting analysis following novel taste learning in gustatory cortex and basolateral amygdala reveals clear and transient phosphorylation of ERK I/II, GluA1- AMPARs and GluN2B-NMDARs. However, the activity of other receptors and kinases are correlated with delayed time of association. We now try to identify causality between these molecular pathways and remote associative time.