Effects of different sensory and behavioral manipulations on autotomy caused by a sciatic lesion in rats.

We studied the effects of different sensory and behavioral manipulations on autotomy (self-mutilation). Lidocaine and bupivacaine pretreatments of the transected nerves delayed the onset of autotomy. Short prelesional stimulation (crush) of the transected nerve did not enhance autotomy significantly. Daily handling decreased autotomy behavior strongly and a visual cue placed on the denervated skin increased autotomy slightly. The delayed onset of the autotomy behavior after locally administered anesthetics suggests that the lesion-induced afferent barrage modified self-mutilation. The decreased self-mutilation after daily handling could be a consequence of handling stress. The increase of autotomy after the visual cue might have resulted from the attention-induced increase of the activity in ascending nociceptive tracts.