Site of action of opioid receptor is:: (A) Area postrema, (B) Dorsal horn, (C) Injury site, (D) Brain
Answer is A. Opioid receptors subtypes "u" and "k" receptors ;high density of u receptor detected in periaqueductal gray,thalamus,nucleus tract us solitarus ,nucleus ambiguous,area postrema. Ref KD Tripathi 8th ed.