title: Memory-Guided Stumbling Correction in the Hindlimb of Quadrupeds Relies on Parietal Area 5.
abstract: In complex environments, tripping over an unexpected obstacle evokes the stumbling corrective reaction, eliciting rapid limb hyperflexion to lift the leg over the obstruction. While stumbling correction has been characterized within a single limb in the cat, this response must extend to both forelegs and hindlegs for successful avoidance in naturalistic settings. Furthermore, the ability to remember an obstacle over which the forelegs have tripped is necessary for hindleg clearance if locomotion is delayed. Therefore, memory-guided stumbling correction was studied in walking cats after the forelegs tripped over an unexpected obstacle. Tactile input to only one foreleg was often sufficient in modulating stepping of all four legs when locomotion was continuous, or when hindleg clearance was delayed. When obstacle height was varied, animals appropriately scaled step height to obstacle height. As tactile input without foreleg clearance was insufficient in reliably modulating stepping, efference, or proprioceptive information about modulated foreleg stepping may be important for producing a robust, long-lasting memory. Finally, cooling-induced deactivation of parietal area 5 altered hindleg stepping in a manner indicating that animals no longer recalled the obstacle over which they had tripped. Altogether, these results demonstrate the integral role area 5 plays in memory-guided stumbling correction.
authors.affiliation: Cerebral Systems Laboratory, University of Western Ontario, London, Ontario, Canada N6A 5K8.|Graduate Program in Neuroscience, University of Western Ontario, London, Ontario, Canada N6A 5K8.
authors.forename: Carmen
authors.initials: C
authors.lastname: Wong
authors.affiliation: Cerebral Systems Laboratory, University of Western Ontario, London, Ontario, Canada N6A 5K8.|Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada N6A 5K8.
authors.forename: Gary
authors.initials: G
authors.lastname: Wong
authors.affiliation: Department of Physiology, University of Alberta, Edmonton, Alberta, CanadaT6G 2H7.
authors.forename: Keir G
authors.initials: KG
authors.lastname: Pearson
authors.affiliation: Cerebral Systems Laboratory, University of Western Ontario, London, Ontario, Canada N6A 5K8.|Graduate Program in Neuroscience, University of Western Ontario, London, Ontario, Canada N6A 5K8.|Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada N6A 5K8.|Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada N6A 5K8.|Department of Psychology, University of Western Ontario, London, Ontario, Canada N6A 5K8.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Lomber
mesh_terms: D000818:Animals; D002415:Cats; D005260:Female; D006614:Hindlimb / Q000502:physiology*; D008124:Locomotion / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D016138:Walking / Q000502:physiology*
keywords: cat; cortical cooling; locomotion; obstacle avoidance; working memory