Dopamine D3 receptor knock-out mice display deficits in locomotor sensitization after chronic morphine administration

▶ The D3 KO mice did not display an enhanced locomotor response to acute morphine administration. ▶ The D3 KO mice did not develop locomotor sensitization to intermittent morphine administration. ▶ Nafadotride inhibits development of locomotor sensitization to morphine. ▶ Naloxone inhibits development of locomotor sensitization to morphine.