Evaluation of innate anxiety in Ta1tubulin-cre/Ikbkap -/- mice : the effects of the IKAP protein deletion from the central nervous system

Abstract

Familial Dysautonomia (FD) is a hereditary sensory and autonomic neuropathy (Type III) marked by a mutation within the Ikbkap gene encoding the IKAP protein. This mutation is prevalent in 99% of the clinical FD population (Shobhat & Halpern, 2010). Symptoms include emotional labiality, cardiovascular instability, vomiting crises and decreased pain and temperature sensation. One clinical symptom associated with FD is increased anxiety in response to stressful situations (Axelrod, 2006). Dr. Lefcort in the department of Biology and Neuroscience at Montana State University has generated a novel mouse model of FD in which Ikbkap is selectively deleted from CNS neurons. The present study characterized the expression of anxiety behaviors in this mouse model using a standard elevated plus maze task. It was observed that FD mice spent significantly more time in the open arms relative to control mice. These mice exhibited significantly greater instances of unprotected head-dipping and fewer protected head-dipping compared to controls. The FD mice also traveled slower than controls but time immobile and distances traveled were found to be similar. These data suggest that the FD mice presented as less anxious, an observation that is inconsistent from observations in the clinical population. Additional research aimed at characterizing the behavioral phenotype of these mice is under investigation.