Table 3.

Behavioral definitions of opioid withdrawal signs in the neonatal rat

Behavior	Definition
Body curl	Ventral or lateral flexion of trunk
Body stretch	Extension or dorsal flexion of trunk causing apparent lengthening of body
Body tremor	Mild lateral movements of head that progress to a full-body lateral tremor
Face wiping	Wiping of both forelimbs across the face
Foreleg movements	Flexion, extension, or rotation of one or both forelegs
Hindleg movements	Flexion or extension of one or both hindlegs
Head movements	Ventral, dorsal or lateral rotary motion of the head
Wall climbing	Placing at least two forepaws on the wall of the observation cage and moving them up and down
Locomotion	Walking across the cage
Quiet	Sedated appearance with no movement for at least 50% of the sample

Used with permission from the Journal of Pharmacology and Experimental Therapeutics⁶