a number of animal models have been used to study, understand and characterize the scratch reflex. these models include the turtle, cat, frog, dog, and a variety of other vertebrates. in these studies, researchers made use of "spinal" preparations, which involve a complete transection of the animal's spinal cord prior to experimentation. such preparations are used because the scratch reflex can be elicited and produced "without" the involvement of supraspinal structures. researchers focused predominantly on investigating spinal cord neural circuitry responsible for the generation of the scratch reflex, limiting the system of study.