UNRESTRAINED WALKING IN CATS WITH MEDIAL PONTINE RETICULAR LESIONS

The early postoperative effects of lesions, aimed to destroy the cauda l pole of the nucleus reticularis pontis oralis (NRPO) and the rostral pole of the nucleus reticularis pontis caudalis (NRPC), were tested i n freely moving cats, walking at moderate speed (0.4-1.0 m/s). In cats in which these structures were partly or completely destroyed, the ma in effect of lesions was an impairment of fore-hindlimb coordination, as shown by a change in the relationships between the lateral and diag onal time shift durations and the step cycle duration. In the second w eek after the surgery the values of the slopes of linear regressions r elating these variables were markedly changed as compared to the preop erative data. The results suggest that the NRPO and NRPC are involved in maintaining the proper fore-hindlimb coordination during unrestrain ed locomotion in cats.