In the context of animal phenotype, a preclinical experimental study intended to dissect how sex and chronic immobilisation stress (CIS) affect glutamate receptor subunit trafficking in the hippocampal CA3 pyramidal neurons following oxycodone CPP, with a particular focus on NMDA (GluN1) and AMPA (GluA1) receptors. This evidence concerns the gene GRIN1 and in situ carcinoma.