Visuospatial impairments in aged canines (Canis familiaris): The role of cognitive-behavioral flexibility.

Abstract

This study used a novel delayed nonmatching-to-position task to compare visuospatial learning and memory in young and aged beagle dogs (Canis familiaris). The task used 3, rather than 2, spatial locations, which markedly increased difficulty. There were striking age differences in acquisition. Most of the aged canines did not learn the task, and those that did showed impaired learning when compared with the young canines. The aged canines also showed reduced maximal working memory capacity compared with the young canines. Analysis of the response patterns of individual canines indicated that the deficits were related to the use of ineffective strategies and inflexibility in strategy modification.

Proteomic identification of brain proteins in the canine model of human aging following a long-term treatment with antioxidants and a program of behavioral enrichment: Relevance to Alzheimer's disease

“…The cognitive enrichment consisted of a landmark discrimination task, an oddity discrimination task [78], and size concept learning [109]. In addition, all animals, regardless of treatment condition were evaluated annually on a test of visuospatial memory [36], object recognition memory [30] and either size discrimination and reversal learning [108], or black/white discrimination and reversal on consecutive years.…”

“…Within 8 months of euthanasia, animals were given an black/white discrimination and reversal problem that is impaired in aged animals and is significantly improved in both antioxidant treated and/or behaviorally enriched animals [80]. Also within a year of the end of the study, spatial memory was tested using a nonmatching to position paradigm described previously to be sensitive to age in dogs [36]. All of the testing procedures were described in previous publications [36,80].…”

“…Also within a year of the end of the study, spatial memory was tested using a nonmatching to position paradigm described previously to be sensitive to age in dogs [36]. All of the testing procedures were described in previous publications [36,80].…”

“…Aged canines show reduced cerebral volume, cortical atrophy and ventricular widening by in vivo magnetic resonance imaging [103,110,111]. The aging canine also shows impairments in visuospatial working memory and executive function [36,102,108]. Aged beagle brain accumulates amyloid-β-peptide (Aβ) that is of the same sequence as humans [63,96] and is correlated with decline in cognitive function with age [43,51].…”

Assessment of nutritional interventions for modification of age-associated cognitive decline using a canine model of human aging

“…Procedural learning and memory, as well as simple discrimination learning, are generally insensitive to aging (Milgram et al 1994). By contrast, tests of executive function, such as discrimination reversal learning (Milgram et al 1994;Tapp et al 2003a), and working memory (Adams et al 2000b;Head et al 1995), such as a delayednonmatching-to-position (DNMP) task (Chan et al 2002), are highly sensitive to aging. In other instances, age sensitivity depends on prior test experience.…”