Roshan Nanu

Katz and Jadhav Labs

“Contribution of the BLA and Stk11 to the learning of taste aversion”

All humans understand the concept of a conditioned taste aversion, even if the term is unfamiliar. It is the feeling of disgust we experience when presented with a food or drink that has previously made us sick (tequila, perhaps?). Mr. Nanu presented his work looking for the genetics behind this learned response, noting that the gene STK11 appears to play a key role.

Learning to distinguish which substances are safe to consume is essential for survival. In mammals, this learning is achieved by the association of consumed tastes with visceral information that comes minutes or even hours later. In rodents, we can force this learning by presenting animals with neutral or even palatable tastants and then giving an injection of Lithium Chloride to induce gastric malaise. Animals will quickly learn to avoid the given taste through a form of learning known as conditioned taste aversion (CTA). Studies have already identified that this learning relies heavily on interaction between gustatory cortex (GC) in the insula and the basolateral amygdala (BLA) which projects heavily to ventral GC. GC neurons respond to tastes in a dynamic fashion by first indicating taste identity and then the palatability of the taste. It is this later palatability response that changes over CTA; a change that is driven by the activity of BLA projection neurons. Furthermore, a genetic screen identified that the tumor-suppressor gene STK11 is necessary for proper learning of aversion, and when it is knocked-down prior to CTA, learning does not occur. Here we seek to extend these genetic findings to the systems level by examining how GC neurons change their responses over CTA when STK11 is knocked-down. Though preliminary, our results seem to indicate that rather than preventing late-phase response changes, STK11 KD results in widespread changes in neuronal responses to tastes from baseline firing changes to response changes as early as the identity phase.