Deactivation of posterior insula does not modify cardiovascular variables in conscious rats

Abstract

The interoceptive system continuously updates homeostatic and emotional information, which are essential elements in motivational decisions. The continuous processing of interoceptive visceral signals in the insular cortex, a key region of the interoceptive system, seems to be involved in the perception of bodily states and emotional responses. We had previously shown that the reversible inactivation of the posterior insula with lidocaine transiently disrupted the drug craving behavior and malaise induced by lithium. However, role played by the insular cortex in the control of autonomic variables, an important component of the emotional responses remains unexplored. Thus, we tested the effect of the reversible inactivation of the insular cortex with neosaxitoxin, a voltage-dependent sodium channel blocker, on body temperature, arterial pressure and heart rate in conscious rats.