Browsing by Subject "Aging."
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Item Acute alcohol produces ataxia and cognitive impairments in aged animals : a comparison between young adults and aged rats.(2013-05-15) Novier, Adelle.; Diaz-Granados, Jaime L.; Matthews, Douglas B.; Psychology and Neuroscience.; Baylor University. Dept. of Psychology and Neuroscience.Aging in both humans and rodents appears to be accompanied by physiological changes that increase biological sensitivity to ethanol intoxication; however, animal models designed to investigate the behavioral significance of increased alcohol sensitivity have yet to be established. The present study sought to determine if acute ethanol administration produces differential effects on motor coordination and spatial performance in adult and aged rats. Findings revealed a dramatic increase in ethanol induced ataxia and cognitive impairment in aged animals relative to young adults as evaluated by several behavioral tasks. Importantly, the heightened deficits seen in aged animals were not due to differential blood ethanol levels. Possible neurophysiological mechanisms are proposed to explain the age-related increase in sensitivity to motor- and cognitive-impairing effects of ethanol. Given the high prevalence of alcohol use among the elderly, increased vulnerability to alcohol-induced deficits may have a profound effect on injury and quality of life in this population.Item The effect of dietary folate deficiency and age on methylation metabolites, neurotransmitters, and behavior in mice.(2011-01-05T19:46:26Z) Wasek, Brandi Lynn.; Bottiglieri, Teodoro, 1958-; Biomedical Studies.; Baylor University. Institute of Biomedical Studies.Severe folate deficiency caused by inborn errors of metabolism has profound deleterious effects in the CNS such as mental retardation, psychiatric disorders, seizures and myelopathy. Mild folate deficiency, due to dietary insufficiency, drugs, or a common mutation in the gene encoding methylenetetrahydrofolate reductase (MTHFR C677T), are associated with an increased risk for depression and dementia, especially in the aging population. The metabolism of folate is intimately linked with the synthesis of S-adenosylmethionine (SAM), the sole source of methyl groups required in methyltransferase reactions. S-adenosylhomocysteine (SAH), a product of methylation reactions, accumulates in folate deficiency due to increased conversion from homocysteine. Recent studies have linked hyperhomocysteinemia and hypomethylation to gene activity, as well as methylation dependent post-translational modification of proteins and neurotransmitter metabolism in depression and dementia. To better define the role of folate deficiency in CNS function, we fed young and old C57BL/6J mice folate deficient diets for 3 months and old heterozygous tg-MTHFR mice a low folate diet for 6 months. Mice were tested for grip strength, coordination, open field activity, and spatial memory. After treatment mice were sacrificed by CO2 asphyxiation or microwave radiation. Blood, peripheral and regional brain tissues were processed for the analysis of methylation and neurotransmitter metabolites. Age did not influence brain methylation metabolites in C57BL/6J mice. Low folate and folate deficient diets decreased the SAM/SAH ratio, an indicator of methylation status in most brain regions from C57BL/6J and heterozygous tg-MTHFR mice. Overall, the effects of folate deficiency were not exacerbated by age in C57BL/6J mice. Brain methylation metabolites differed significantly depending on the method of sacrifice. Specifically, folate deficiency decreased SAM in mice sacrificed by microwave radiation and increased SAH in mice sacrificed by asphyxiation. Folate deficiency reduced dopamine and serotonin turnover in several brain regions although the levels of the parent neurotransmitters were unaffected. Choline and acetylcholine levels were reduced by folate deficiency in the mid-brain. Folate deficiency impaired open field behavior, but did not have any significant effect on spatial memory. These studies help to further our understanding of the mechanisms involved in folate deficiency on CNS function in the aging brain.Item The effects of a 12-week resistance training program combined with casein or whey protein supplementation on body composition, muscle strength, and markers of satellite cell activation in older males.(2010-10-08T16:12:13Z) Allison, Annie G.; Cooke, Matthew B.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Resistance training and protein supplementation have been shown to increase muscle mass and strength, and thus may be an effective method to combat muscle wasting (sarcopenia) that occurs with aging. Thirty-six males (62.5 yrs, 177 cm and 95.25 kg) were randomly assigned to ingest either whey isolate protein, casein protein or carbohydrate while participating in a 12-week high intensity resistance training program. Resistance training increased both upper and lower body strength, body mass and lean muscle mass while decreasing body fat percentage. However, no effects from training were observed on serum anabolic hormones and indirect markers of satellite cell activation. A trend towards significantly higher lower body strength was observed in the whey isolate (p=0.053) and casein (p=0.086) groups, respectively, compared to carbohydrate placebo group. The present study suggests protein supplementation in conjunction with high intensity resistance training may be important in combating sarcopenia.