Chronic dietary aspartame may impair rodent insulin tolerance and may affect behavior. Previous studies have shown the aspartame effects may be modulated by developmental NMDA receptor antagonism. Present study was designed to assess effects of aspartame and NMDAR antagonism on components of the HPA axis. We used microarray analysis to examine changes in adult rodent adrenal gene expression following chronic aspartame exposure and/or developmental NMDA receptor antagonism. Overall design: Aspartame exposure in C57Bl/6J mice commenced in utero via the mother's diet. NMDAR antagonism with the competitive drug CGP 39551 was limited to the developmental period (E0 to P28). Control mice received neither dietary aspartame nor developmental NMDAR antagonism. At 21 weeks of life animals were euthanized and RNA was extracted from snap-frozen mouse adrenal tissue for microarray analysis.