The Relationships Between the Noradrenergic, Opioid and Pain System

The role of alpha2 receptor agonist on pain perception and modulation will be examined. In addition whether this is mediated through the opioid system will be examined. Pain perception and modulation will be examined before and after administration of Clonidine or placebo together with Naloxone or saline.

Inclusion Criteria:

• Healthy volunteers
• Age 18-40
• No chronic disease

Exclusion Criteria:

• Subjects who suffer from chronic pain / pain syndrome
• use of anti-depressant or anti-psychotic drugs
• suffering from cardiovascular disease
• breast feeding