THE EFFECTS OF VASOPRESSIN AND OXYTOCIN ON REELIN EXPRESSION IN PURKINJE CELLS

Abstract

Recent evidence suggests that about 90% of autism spectrum disorders have a genetic basis (Plomin, et al.1997). Autism and its related disorders are defined by three primary characteristics: social deficits, repetitive behaviors and language impairment. The RELN gene is among the many suspects for conferring vulnerability to autism spectrum disorders. This gene is responsible for the production of reelin, an extracellular matrix glycoprotein involved in embryonic neurodevelopment and neuronal signaling and migration in adult life. Individuals with autism have reduced levels of reelin in blood and brain tissue. As of yet, no single polymorphism in RELN explains this reduced protein level. As with many disorders which vary along a continuum, epigenetic factors may contribute to the expression of the gene. In a recent review article, Carter suggests that vasopressin and oxytocin may either be regulated by or regulate reelin expression (2007). The work proposed herein will investigate the effect of various quantities of these neuropeptides on reelin expression in Purkinje cells through reelin immunostaining and Western blotting. Reelin expression will be enhanced (by co-transfection of cells) and inhibited (by use of siRNAs) in order to understand how these conditions affect oxytocin and vasopressin levels. The effects of these conditions on Purkinje cell morphology and viability will be assessed using a trypan blue exclusion assay and digital inverted microscopy. It is hypothesized that oxytocin will enhance reelin expression, while vasopressin will result in lower than normal or unchanged reelin levels. Specific Aims: 1. To observe the effect of exogenous oxytocin and vasopressin, alone and in combination, on reelin expression in Purkinje cells; 2.To determine the effect of reduced or increased reelin expression on oxytocin and vasopressin levels in Purkinje cells; 3. To observe the effect of altered exposure to oxytocin and vasopressin on Purkinje cell morphology and viability. Relevance to Public Health: Understanding how reelin is regulated could allow development of a mechanism for enhancing these levels in the brain and blood tissue of individuals with ASDs. If reelin levels are increased, some autism symptoms may be ameliorated.