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Corr, J. A. (2004). Nuns and monkeys: investigating the behavior of our oldest old. Sci Aging Knowledge Environ, 2004(41), pe38.
Abstract: The use of nonhuman primates, particularly rhesus macaques (Macaca mulatta), as the best model for human physiological and cognitive aging is broadly accepted. Studies employing nonhuman primates to investigate behavioral changes that may occur with increasing age, however, are not common mostly because of the unavailability of appropriate subjects. Recent longitudinal human studies suggest that individual personality might play a large role in aging “successfully” and in the retention of high levels of cognition into old age. As a result of the demographic trend of increasing numbers of aged monkeys and apes in captivity, an opportunity exists to further investigate behavioral aging using the monkey model.
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Milgram, N. W., Head, E., Muggenburg, B., Holowachuk, D., Murphey, H., Estrada, J., et al. (2002). Landmark discrimination learning in the dog: effects of age, an antioxidant fortified food, and cognitive strategy. Neurosci Biobehav Rev, 26(6), 679–695.
Abstract: The landmark discrimination learning test can be used to assess the ability to utilize allocentric spatial information to locate targets. The present experiments examined the role of various factors on performance of a landmark discrimination learning task in beagle dogs. Experiments 1 and 2 looked at the effects of age and food composition. Experiments 3 and 4 were aimed at characterizing the cognitive strategies used in performance on this task and in long-term retention. Cognitively equivalent groups of old and young dogs were placed into either a test group maintained on food enriched with a broad-spectrum of antioxidants and mitochondrial cofactors, or a control group maintained on a complete and balanced food formulated for adult dogs. Following a wash-in period, the dogs were tested on a series of problems, in which reward was obtained when the animal responded selectively to the object closest to a thin wooden block, which served as a landmark. In Experiment 1, dogs were first trained to respond to a landmark placed directly on top of coaster, landmark 0 (L0). In the next phase of testing, the landmark was moved at successively greater distances (1, 4 or 10 cm) away from the reward object. Learning varied as a function of age group, food group, and task. The young dogs learned all of the tasks more quickly than the old dogs. The aged dogs on the enriched food learned L0 significantly more rapidly than aged dogs on control food. A higher proportion of dogs on the enriched food learned the task, when the distance was increased to 1cm. Experiment 2 showed that accuracy decreased with increased distance between the reward object and landmark, and this effect was greater in old animals. Experiment 3 showed stability of performance, despite using a novel landmark, and new locations, indicating that dogs learned the landmark concept. Experiment 4 found age impaired long-term retention of the landmark task. These results indicate that allocentric spatial learning is impaired in an age-dependent manner in dogs, and that age also affects performance when the distance between the landmark and target is increased. In addition, these results both support a role of oxidative damage in the development of age-associated cognitive dysfunction and indicate that short-term administration of a food enriched with supplemental antioxidants and mitochondrial cofactors can partially reverse the deleterious effects of aging on cognition.
Keywords: Age Factors; Aging/*physiology; Analysis of Variance; Animals; Antioxidants/*pharmacology; Blood Chemical Analysis/methods; Cognition/*physiology; *Diet; Discrimination Learning/*drug effects/*physiology; Distance Perception/drug effects/physiology; Dogs/physiology; Female; Male; Psychomotor Performance/physiology; Retention (Psychology)/drug effects/physiology; Spatial Behavior/*drug effects/*physiology; Task Performance and Analysis; Time Factors; Vitamin E/blood
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van Heel, M. C. V., Kroekenstoel, A. M., van Dierendonck, M. C., van Weeren, P. R., & Back, W. (2006). Uneven feet in a foal may develop as a consequence of lateral grazing behaviour induced by conformational traits. Equine. Vet. J., 38(7), 646–651.
Abstract: REASONS FOR PERFORMING STUDY: Conformational traits are important in breeding, since they may be indicative for performance ability and susceptibility to injuries. OBJECTIVES: To study whether certain desired conformational traits of foals are related to lateralised behaviour while foraging and to the development of uneven feet. METHODS: Twenty-four Warmblood foals, born and raised at the same location, were studied for a year. Foraging behaviour was observed by means of weekly 10 min scan-sampling for 8 h. A preference test (PT) was developed to serve as a standardised tool to determine laterality. The foals were evaluated at age 3, 15, 27 and 55 weeks. The PT and distal limb conformation were used to study the relation between overall body conformation, laterality and the development of uneven feet. Pressure measurements were used to determine the loading patterns under the feet. RESULTS: About 50% of the foals developed a significant preference to protract the same limb systematically while grazing, which resulted in uneven feet and subsequently uneven loading patterns. Foals with relatively long limbs and small heads were predisposed to develop laterality and, consequently unevenness. CONCLUSIONS: Conformational traits may stimulate the development of laterality and therefore indirectly cause uneven feet.
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