A technique for the study of spatiotemporal aspects of paw contact patterns,applied to rats treated with a TRH analogue

The analysis of footfall patterns can help in the evaluation of normal and disturbed neurological function. Previous methods, however, such as inking the feet, give only a snapshot of maximum contact without temporal information. This paper describes the use of an alternative technique, with which these limitations can be overcome through the use of light reflected within a glass plate to illuminate paw contact areas during the stance phase of locomotion. Computer analysis demonstrates no difference in maximum contact area between forepaws and hindpaws, with the major contact structures being pads DP2 and DP3, but there are numerous differences in deployment. For example, the forepaw deploys tactile sensory-rich structures early in the contact cycle. The effects of TRH analogue CG3703 on aspects of hindpaw contact demonstrate that treated rats make more extensive use of distal parts of the paw. The results are discussed in terms of CG3703-induced postural changes.