Mapping canine learning and memory systems
Subtitle: functions of the rhinal and dorsolateral prefrontal cortices in object and visuospatial learning and memo
By: by Lori-Ann Christie.
Published: 2006
Language: eng
Number of pages: 164
ISBN-13: 9780494158685
Description: The first experiment describes a novel task developed to assess egocentric spatial learning in which dogs had to respond to one of two stimuli based on their spatial location relative to the animals' own body position. The initial task was acquired readily and was insensitive to age. However, when the stimulus-reward contingencies were reversed, old dogs showed difficulty in switching their responses. The egocentric task's development is described because the perseverative-type reversal learning deficits found in old dogs suggested that the task was effective in measuring frontal lobe function, and so it became a potentially useful paradigm for testing the effects of dlPFC lesions in Experiment 3.The present investigation used the lesion technique to examine the functional organization of the dog's brain in tests of object and spatial learning and memory. The initial motivation for studying canine functional neuroanatomy was part of a larger endeavour to develop the dog as a model of human aging and cognition. The experiments described in this dissertation represent the first attempt to characterize the role of the canine rhinal cortex (RC) and dorsolateral prefrontal cortex (dlPFC) in visually-based tasks that assess object and spatial learning and memory.In Experiments 2 and 3, simultaneous training on conceptually and procedurally analogous object and spatial tasks allowed us to directly compare the effects of RC and dlPFC removal on object versus spatial memory. In Experiment 2, removal of the canine RC selectively disrupted performance on tasks in which object information had to be processed and remembered, but left visuospatial performance completely unaffected. In Experiment 3, removal of the canine dlPFC produced impairments in visuospatial executive functions. A selective and transient impairment in retention of the rules required to perform a spatial delayed non-matching task was found, while mnemonic performance on the task remained intact. Perseverative responding on an egocentric spatial reversal task was increased following damage to the dlPFC, suggesting that this region in the dog is also involved in inhibitory control capacity, a decline in which may underlie the age-related deficits found in Experiment 1.
Notes: Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3610.

Thesis (Ph.D.)--University of Toronto, 2006.

Includes bibliographic references.

Electronic version licensed for access by U. of T. users.