893 resultados para Biology, Neuroscience|Psychology, Experimental|Psychology, Physiological
Resumo:
BACKGROUND Cognitive impairment is a common feature in multiple sclerosis (MS) patients and occurs in 60% of all cases. Unfortunately, neurological examination does not always agree with the neuropsychological evaluation in determining the cognitive profile of the patient. On the other hand, psychophysiological techniques such as event-related potentials (ERPs) can help in evaluating cognitive impairment in different pathologies. Behavioural responses and EEG signals were recorded during the experiment in three experimental groups: 1) a relapsing-remitting group (RRMS), 2) a benign multiple sclerosis group (BMS) and 3) a Control group. The paradigm employed was a spatial attention task with central cues (Posner experiment). The main aim was to observe the differences in the performance (behavioural variables) and in the latency and amplitude of the ERP components among these groups. RESULTS Our data indicate that both MS groups showed poorer task performance (longer reaction times and lower percentage of correct responses), a latency delay for the N1 and P300 component, and a different amplitude for the frontal N1. Moreover, the deficit in the BMS group, indexed by behavioural and pyschophysiological variables, was more pronounced compared to the RRMS group. CONCLUSION The present results suggest a cognitive impairment in the information processing in all of these patients. Comparing both pathological groups, cognitive impairment was more accentuated in the BMS group compared to the RMSS group. This suggests a silent deterioration of cognitive skills for the BMS that is not usually treated with pharmacological or neuropsychological therapy.
Resumo:
OBJECTIVE. The purpose of this study was to analyze change of lifestyle in obese patients with cognitive behavior therapy and acupressure. METHODS. An experimental study was performed with placebo control group. Forty patients were randomly assigned to intervention group (cognitive behaviour therapy + acupressure) and control group (information session). Outcome measure was a questionnaire for the assessment and quantification of obesity related lifestyles. Measures were performed at baseline and, after 3-months intervention. RESULTS. After 3 months of treatment, the intervention group showed significant differences (p<0.05) in weight loss, diet and physical activity. CONCLUSION. In the obese patient, cognitive behavior therapy and acupressure, it has lost at least three kilograms over three months and has changed lifestyles related to obesity.
Resumo:
In recent years it has been shown that emotional stress induced by immobilization may change the balance between pro-oxidant and antioxidant factors inducing oxidative damage. On the other hand, contradictory views exist concerning the role of physical activity on redox metabolism. Consequently, the present work was designed to assess the influence of an 8-week moderate swimming training program in emotionally stressed rats. Sixty 1-month-old male albino Wistar rats weighing 125-135 g were used in this experimental study. They were divided into three groups, as Control (lot A; n=20), Stressed (lot B; n=20) and Stressed & Exercised (lot C; n=20). Rats were stressed by placing the animals in a 25 x 7 cm plastic bottle 1 h/day, 5 days a week for 8 weeks. Protein carbonyl content values in liver homogenates were significantly increased in stressed animals (0.58+/-0.02 vs 0.86+/-0.03; p=0.018) which clearly indicated that emotional stress was associated with oxidative stress. Ultrastructural alterations, predominantly mitochondrial swelling and the decrease of cristae number observed by electron microscopy represented direct evidence of membrane injury. The most striking feature of our study was that we also found differences between stressed rats and stressed rats that performed our 8 week training program. Consequently our results highlight the potential benefit of a moderate training program to reduce oxidative damage induced by emotional stress since it attenuated protein oxidation and mitochondrial alterations.
Resumo:
Evidence shows that the endocannabinoid system modulates the addictive properties of nicotine. In the present study, we hypothesized that spontaneous withdrawal resulting from removal of chronically implanted transdermal nicotine patches is regulated by the endocannabinoid system. A 7-day nicotine dependence procedure (5.2 mg/rat/day) elicited occurrence of reliable nicotine abstinence symptoms in Wistar rats. Somatic and affective withdrawal signs were observed at 16 and 34 hours following removal of nicotine patches, respectively. Further behavioral manifestations including decrease in locomotor activity and increased weight gain also occurred during withdrawal. Expression of spontaneous nicotine withdrawal was accompanied by fluctuation in levels of the endocannabinoid anandamide (AEA) in several brain structures including the amygdala, the hippocampus, the hypothalamus and the prefrontal cortex. Conversely, levels of 2-arachidonoyl-sn-glycerol were not significantly altered. Pharmacological inhibition of fatty acid amide hydrolase (FAAH), the enzyme responsible for the intracellular degradation of AEA, by URB597 (0.1 and 0.3 mg/kg, i.p.), reduced withdrawal-induced anxiety as assessed by the elevated plus maze test and the shock-probe defensive burying paradigm, but did not prevent the occurrence of somatic signs. Together, the results indicate that pharmacological strategies aimed at enhancing endocannabinoid signaling may offer therapeutic advantages to treat the negative affective state produced by nicotine withdrawal, which is critical for the maintenance of tobacco use.
Resumo:
Alterations in motor functions are well-characterized features observed in humans and experimental animals subjected to thyroid hormone dysfunctions during development. Here we show that congenitally hypothyroid rats display hyperactivity in the adult life. This phenotype was associated with a decreased content of cannabinoid receptor type 1 (CB(1)) mRNA in the striatum and a reduction in the number of binding sites in both striatum and projection areas. These findings suggest that hyperactivity may be the consequence of a thyroid hormone deficiency-induced removal of the endocannabinoid tone, normally acting as a brake for hyperactivity at the basal ganglia. In agreement with the decrease in CB(1) receptor gene expression, a lower cannabinoid response, measured by biochemical, genetic and behavioral parameters, was observed in the hypothyroid animals. Finally, both CB(1) receptor gene expression and the biochemical and behavioral dysfunctions found in the hypothyroid animals were improved after a thyroid hormone replacement treatment. Thus, the present study suggests that impairment in the endocannabinoid system can underlay the hyperactive phenotype associated with hypothyroidism.
Resumo:
CONTEXT The association between thyroid function during pregnancy and the later mental and psychomotor development of the child is supported by numerous experimental, clinical, and epidemiological studies. OBJECTIVE The aim of the study was to evaluate the psychological development of infants aged 3 to 18 months whose mothers had received 300 microg of potassium iodide during the first trimester of their pregnancy and compare with infants whose mothers had received no iodine supplements. DESIGN AND STUDY SUBJECTS: The study included 133 women who had received 300 microg of potassium iodine and 61 women who had received no iodine supplements. MAIN OUTCOME MEASURES The neuropsychological status of the children was evaluated with the Bayley Scales of Infant Development, and measurements were made of TSH, free T(3), free T(4), and urinary iodine. RESULTS Those children whose mothers had received an iodine supplement of 300 microg had a more favorable psychometric assessment than those of the other group of mothers. They had higher scores on the Psychomotor Development Index (P = 0.02) and the Behavior Rating Scale. CONCLUSIONS Dietary iodine supplements not only have no harmful effect on the neurodevelopment of the children, they may even be beneficial. Given the possible presence of confounding variables not controlled for in this study, these findings should be considered as preliminary.