SPLTRAK Abstract Submission
State-dependent Coding: LiCl-induced State Suppresses Gustatory Cortex Processing  
Bradly / T Stone & Donald / B Katz
Brandeis University, Waltham, MA, United States

A large literature addresses how toxicity by way of drug injection (commonly lithium chloride; LiCl) shapes aversive behavior, but few studies have delved into the nature of this powerful state itself. Such states influence an animal’s interactions with its environment, potentially affecting its feeding behavior through modifications of taste perception: an animal that is ill, for instance, is less likely to find food appetitive (a fact that can potentially prolong infirmity by demotivating the animal to ingest nutrient). Here, we report the beginning of an investigation into how the spontaneous network state induced by LiCl specifically impacts taste processing, and how the activity underlying this internal state might support learning. Using extracellular (single-neuron and local field potentials; LFPs) recordings during a passive taste delivery task under two (LiCl-induced sickness and Neutral) conditions, I demonstrate evidence that network state changes induced by internal state manipulations are both represented in the gustatory cortex (GC) and impact taste processing. I show rhythmic activity in the 7-12Hz range emerges at 12 minutes post injection of LiCl and vanishes 6 minutes later, reflecting the onset of malaise, while taste discriminability and palatability correlates (as assessed through ensemble statistics) are significantly reduced in comparison to neutral state. The later suggests the maintenance of internal state impact on cortical activity as they relate to hallmarks of taste processes. These results provide powerful evidence towards the function that an animal’s welfare has on the establishment and maintenance of natural reward valuation and associative effects of stimuli.