Tail pinch behavior and analgesia in diabetic mice.

Mild tail pinch induced "consummatory" behaviors in mice. The major tail pinch behavior appeared to be chewing with food ingestion occurring possibly as an epiphenomenon. All tail pinch behaviors were obliterated by the dopamine antagonist haloperidol; and the opiate antagonist, naltrexone, decreased eating without altering chewing. The combination of dopamine blockade and tail pinch induced jumping behavior in mice. Diabetic mice showed increased tail flick latencies to radiant heat and to the induction of tail pinch behaviors, displaying these behaviors less commonly than their homozygote and heterozygote littermate controls.