Effects of continuous naloxone administration on ventral tegmental self-stimulation

Continuous subcutaneous administration of naloxone (3 mg/kg/h), shifted ventral tegmental self-stimulation rate-frequency curves to the right, without suppressing behavioral performance. In addition this chronic blockade of opioid receptors altered mu binding parameters in the hippocampus and olfactory tubercle of naloxone-treated animals. These findings speak to the role opioid peptides paly in the mediation of brain stimulation reward.