FOOD-TAKING IN THE CAT INVESTIGATED WITH TRANSECTION OF THE RUBRO-SPINAL AND CORTICOSPINAL TRACTS

In cats with the distal paw shaved food-taking fi-om a horizontally or vertically placed tube was recorded with a video camera, supplementar y results were obtained with a high frequency video system. Measuremen ts were made of the dorsal contour of the digits to investigate angula r movement in the proximal interphalangeal (PIP) joint and withdrawal of the paw before and after complete transection of the rubro- add cor ticospinal tracts just rostral to the forelimb segments. In the preope rative state PIP flexion occurs before withdrawal of the paw in the la rge majority of cats. Postsurgically the main part of PIP flexion is m ade during withdrawal of the paw. It is suggested that PIP flexion bef ore withdrawal allows for accurate manipulative placement of the digit s on the target which depends on the rubro- and corticospinal tracts, while PIP flexion during withdrawal, which may favour speed at the exp ense of accuracy, can be made without the rubro- and corticospinal tra cts. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.