Physiology & behavior
-
Physiology & behavior · Aug 2013
Chronic restricted access to 10% sucrose solution in adolescent and young adult rats impairs spatial memory and alters sensitivity to outcome devaluation.
Although increasing consumption of sugar drinks is recognized as a significant public health concern, little is known about (a) the cognitive effects resulting from sucrose consumption; and (b) whether the long-term effects of sucrose consumption are more pronounced for adolescents. This experiment directly compared performance on a task of spatial learning and memory (the Morris Water Maze) and sensitivity to outcome devaluation following 28 days of 2-h/day access to a 10% sucrose solution in adolescent and young-adult Wistar rats. ⋯ Further, results from outcome devaluation testing indicated that in the older cohort of rats, those fed sucrose showed reduced sensitivity to devaluation of the outcome, suggestive of differences in instrumental learning following sucrose exposure. Data provide strong evidence that sucrose consumption can induce deficits in spatial cognition and reward-oriented behavior at levels that resemble patterns of sugar drink consumption in young people, and which can remain long after exposure.
-
Physiology & behavior · Jul 2013
Vitamin E prevents high-fat high-carbohydrates diet-induced memory impairment: the role of oxidative stress.
Memory and learning are impaired by imbalanced diet consumption. High-fat high-carbohydrate diet (HFCD) induces oxidative stress, which results in neuronal damage and interference with synaptic transmission; hence, a decline in cognitive function. Vitamin E is a fat soluble antioxidant that is believed to have positive effects on learning and memory. ⋯ The administration of vitamin E normalized the effect of HFCD on the oxidative stress markers. None of the treatments induced changes in the levels of BDNF or glutathione peroxidase (GPx). In conclusion, HFCD induces memory impairment, and the administration of vitamin E prevented this impairment probably through normalizing antioxidant mechanisms in the hippocampus.
-
Physiology & behavior · Jun 2013
Comparative StudyComparison of cough reflex test against instrumental assessment of aspiration.
Silent aspiration is associated with pneumonia and mortality, and is poorly identified by traditional clinical swallowing evaluation (CSE). The aim of this study was to validate cough reflex testing (CRT) for identification of silent aspiration against aspiration confirmed by instrumental assessment. ⋯ CRT results are significantly associated with aspiration response on instrumental assessment. Lower concentrations of citric acid provide a better predictive measure of silent aspiration.
-
Physiology & behavior · Jun 2013
HPA regulation and dating couples' behaviors during conflict: gender-specific associations and cross-partner interactions.
The way romantic partners behave during conflict is known to relate to stress responses, including activation of the hypothalamic-pituitary-adrenal (HPA) axis; however, little attention has been paid to interactive effects of partners' behaviors, or to behavior outside of marital relationships. This study examined relations between unmarried partners' negative and positive behaviors during discussion of conflict and their HPA responses, including both main effects and cross-partner interactions. Emerging adult opposite-sex couples (n=199) participated in a 15-minute conflict discussion and afterward rated their behavior on 3 dimensions: conflictual, holding back, and supportive. ⋯ Women's conflictual behavior only predicted problematic cortisol responses if their partner was highly conflictual or holding back; at lower levels of these partner behaviors, the opposite was true. This work demonstrates similar costs of negative reciprocity and demand-withdraw and benefits of supportive conflict dynamics in dating couples as found in marital research, but associations with HPA are gender-specific. Cross-partner interactions suggest that behavior during discussion of conflict should not be categorized as helpful or harmful without considering the other partner's behavior.
-
Physiology & behavior · Jun 2013
The effect of cocaine on rotarod performance in male C57BL/6J mice.
There is surprisingly little research examining the effect of cocaine on motor learning. Given that changes in motor activity can confound behavioral assays of learning and memory a direct assessment of cocaine on motor learning seems warranted. The present study was conducted to examine the effect of cocaine on motor learning using an accelerating rotarod test in adult male C57BL/6J mice. ⋯ Animals that received cocaine injections exhibited significantly longer latencies to fall on days 3-6 compared to those mice receiving saline. This enhanced performance was lost when cocaine-injected animals were switched to saline on day 7. It is hypothesized that the performance enhancing effects of cocaine are due to the increased stamina and/or psychomotor stimulation and not the result of enhanced motor learning as the increment in performance was lost when the drug was discontinued.