Epilepsy, compulsion and oxytocin: Insights from behavioral sequences, using neuroethology and complexity systems approaches.

Abstract

Epilepsies are complex neurological entities usually co-existing with neuropsychiatric comorbidities. We already demonstrated that microinjection of oxytocin (OT) into the central nucleus of amygdala (CeA) induces hypergrooming in Wistar rats, a model of compulsion. Furthermore, the Wistar Audiogenic Rat (WAR) strain is a genetic model of generalized tonic-clonic seizures. Here we quantified grooming behavior in WAR, with grooming scores, flowcharts and directed graphs of syntactic and non-syntactic grooming chains, after bilateral administration of OT or saline (SAL) into the CeA. Our current pioneer behavioral description considers that hypergrooming (compulsion) in WARs is a comorbidity because: (1) WARs have the highest grooming scores, when exposed only to novelty (2), WARs have better grooming scores than Wistars after CeA-SAL, (3) Epileptic WARs perform much better than Wistars in OT-CeA-dependent stereotyped behavioral sequences (flowcharts of syntactic/non-syntactic grooming chains). One additional observation is that the behavioral sequences here demonstrated can be modeled as reliable Markov chains. In conclusion we can drive hypergrooming in WARs, defined previously as a model of ritualistic motor behavior in Wistar rats, with OT from CeA, one of the principal amygdala complex outputs. As perspectives, ongoing cellular studies are on their way, to demonstrate the neural network, certainly incorporating cortico-striatal-thalamic-basal ganglia-cortical circuits, driven from CeA OT-dependent grooming pattern, a stereotyped, sequential and complex array of behaviors, and its association with seizure susceptibility.