Induction of Type I Diabetes Mellitus in Beagle Dogs Using Alloxan and Streptozotocin.

This article describes a protocol for chemically inducing type I diabetes mellitus in beagle dogs using a mixture of alloxan (ALX) and streptozotocin (STZ). ALX and STZ are both cytotoxic, diabetogenic agents that cause necrosis of pancreatic β-cells and therefore halt the production of insulin. Although both compounds are widely used in experimental animal models of diabetes, standard protocols employing a single high dose of either agent are also implicated in adjacent organ damage.

Pattern separation and goal-directed behavior in the aged canine.

The pattern separation task has recently emerged as a behavioral model of hippocampus function and has been used in several pharmaceutical trials. The canine is a useful model to evaluate a multitude of hippocampal-dependent cognitive tasks that parallel those in humans. Thus, this study was designed to evaluate the suitability of pattern separation task(s) for detecting age-related changes in canines.

Therapeutic effects of an alpha-casozepine and L-tryptophan supplemented diet on fear and anxiety in the cat.

Objectives This study assessed the anxiolytic effectiveness of a test diet (Royal Canin Feline Calm diet) supplemented with L-tryptophan and alpha-casozepine. Methods Subjects were 24 cats that were classified as mildly or markedly fearful based on the presence of a person in their home room. Three different protocols were used to assess anxiety: (1) evaluation of the response to a human in the cat's home room (home room test); (2) analysis of the response to placement in an empty test room (open-field test); and (3) analysis of the response to an unfamiliar human (human interaction test).

Development of a laboratory model to assess fear and anxiety in cats.

Objectives The objectives of this study were: (1) to develop a laboratory-based model to assess fear and anxiety in cats using the feline open-field test (OFT) and the feline human interaction test (HIT); and (2) to validate the model using diazepam, a known anxiolytic. Methods Laboratory-housed cats (n = 41) were first classified as fearful, mildly fearful or non-fearful by a technician familiar with the cats and also by veterinary behaviorists (GL, JL), by assessing the cats' behavior in their home rooms. In experiment 1, each cat's behavior was assessed in an OFT and an HIT.

Effect of mitochondrial cofactors and antioxidants supplementation on cognition in the aged canine.

A growing body of research has focused on modifiable risk factors for prevention and attenuation of cognitive decline in aging. This has led to an unprecedented interest in the relationship between diet and cognitive function. Several preclinical and epidemiologic studies suggest that dietary intervention can be used to improve cognitive function but randomized controlled trials are increasingly failing to replicate these findings.

Exercise enhances memory consolidation in the aging brain.

Exercise has been shown to reduce age-related losses in cognitive function including learning and memory, but the mechanisms underlying this effect remain poorly understood. Memory formation occurs in stages that include an initial acquisition phase, an intermediate labile phase, and then a process of consolidation which leads to long-term memory formation. An effective way to examine the mechanism by which exercise improves memory is to introduce the intervention (exercise), post-acquisition, making it possible to selectively examine memory storage and consolidation.

Cognitive enhancement in middle-aged and old cats with dietary supplementation with a nutrient blend containing fish oil, B vitamins, antioxidants and arginine.

Cognitive dysfunction syndrome is a major disease affecting old cats and is the consequence of severe and irreversible loss of brain cells and brain atrophy. The present study focused on the hypothesis that the optimal strategy for promoting successful brain ageing is to target risk factors associated with brain ageing and dementia. We used a nutritional strategy involving supplementation with a blend of nutrients (antioxidants, arginine, B vitamins and fish oil) to test this hypothesis.

Cholinesterase inhibitors improve both memory and complex learning in aged beagle dogs.

Similar to patients with Alzheimer's disease (AD), dogs exhibit age-dependent cognitive decline, amyloid-β (Aβ) pathology, and evidence of cholinergic hypofunction. The present study sought to further investigate the role of cholinergic hypofunction in the canine model by examining the effect of the cholinesterase inhibitors phenserine and donepezil on performance of two tasks, a delayed non-matching-to-position task (DNMP) designed to assess working memory, and an oddity discrimination learning task designed to assess complex learning, in aged dogs. Phenserine (0.

Age and distraction are determinants of performance on a novel visual search task in aged Beagle dogs.

Aging has been shown to disrupt performance on tasks that require intact visual search and discrimination abilities in human studies. The goal of the present study was to determine if canines show age-related decline in their ability to perform a novel simultaneous visual search task. Three groups of canines were included: a young group (N = 10; 3 to 4.

Dietary supplementation with medium-chain TAG has long-lasting cognition-enhancing effects in aged dogs.

The present study focused on the hypothesis that dietary supplementation with medium-chain TAG (MCT) will improve cognitive function in aged dogs by providing the brain with energy in the form of ketones. Aged Beagle dogs were subjected to a baseline battery of cognitive tests, which were used to establish cognitively equivalent control or treatment groups. The dogs in the treatment group were maintained on a diet supplemented with 5.

Short-term supplementation with acetyl-L-carnitine and lipoic acid alters plasma protein carbonyl levels but does not improve cognition in aged beagles.

Previous work has shown that a diet enriched with antioxidants and mitochondrial co-factors improves cognition in aged dogs, which is accompanied by a reduction in oxidative damage in the brain. The objective of the present study was to assess the effects of supplementation with mitochondrial co-factors on cognition and plasma protein carbonyl levels in aged dogs. Specifically, we aimed to test whether the individual or combined action of lipoic acid (LA) and acetyl-l-carnitine (ALCAR) could account for the beneficial effects of the enriched diet that contained both plus antioxidants.

Children's responses to educators' questions in day care play groups.

An exploratory study examined adults' questions to small groups of children to determine how questions influenced their response rate and complexity of response. Thirteen educators of toddlers and 13 educators of preschoolers were videotaped during free-play. Both groups of educators used an equivalent frequency of open-ended and closed questions, but the preschool educators used more topic-continuing questions.

A novel method for assessing contrast sensitivity in the beagle dog is sensitive to age and an antioxidant enriched food.

Tasks requiring visual discrimination are commonly used in assessment of canine cognitive function. However, little is known about canine visual processing, and virtually nothing is known about the effects of age on canine visual function. This study describes a novel behavioural method developed to assess one aspect of canine visual function, namely contrast sensitivity.