Audiogenic Seizures in the Streptozotocin-Induced Rat Alzheimer's Disease Model.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative and progressive disorder with no cure and constant failures in clinical trials. The main AD hallmarks are amyloid-ß (Aß) plaques, neurofibrillary tangles, and neurodegeneration. However, many other events have been implicated in AD pathogenesis. Epilepsy is a common comorbidity of AD and there is important evidence indicating a bidirectional link between these two disorders. Some studies suggest that disturbed insulin signaling might play an important role in this connection. OBJECTIVE: To understand the effects of neuronal insulin resistance in the AD-epilepsy link. METHODS: We submitted the streptozotocin (STZ) induced rat AD Model (icv-STZ AD) to an acute acoustic stimulus (AS), a known trigger of seizures. We also assessed animals' performance in the memory test, the Morris water maze and the neuronal activity (c-Fos protein) induced by a single audiogenic seizure in regions that express high levels of insulin receptors. RESULTS: We identified significant memory impairment and seizures in 71.43% of all icv-STZ/AS rats, in contrast to 22.22% of the vehicle group. After seizures, icv-STZ/AS rats presented higher number of c-Fos immunopositive cells in hippocampal, cortical, and hypothalamic regions. CONCLUSION: STZ may facilitate seizure generation and propagation by impairment of neuronal function, especially in regions that express high levels of insulin receptors. The data presented here indicate that the icv-STZ AD model might have implications not only for AD, but also for epilepsy. Finally, impaired insulin signaling might be one of the mechanisms by which AD presents a bidirectional connection to epilepsy.

Translation and validation of a Brazilian Portuguese version of the Body Appreciation Scale-2 in Brazilian adults.

We examined the psychometric properties of a Brazilian Portuguese translation of the Body Appreciation Scale-2 (BAS-2; Tylka & Wood-Barcalow, 2015). A sample of 990 Brazilian adults (560 women, 430 men; Mage = 31.10, SD = 8.94) completed the BAS-2 and measures of life satisfaction, self-esteem, actual-ideal weight discrepancy (women only), breast size dissatisfaction (women only), drive for muscularity (men only), and disordered eating behaviours. Exploratory factor analyses indicated that BAS-2 scores reduced to a single dimension with all 10 items in women and men. Confirmatory factor analysis supported the fit of this one-dimensional factor structure following freeing of error covariances between two pairs of items. BAS-2 scores achieved full scalar invariance across sex, and men had significantly higher BAS-2 scores than women. Internal consistency coefficients were adequate and test-retest reliability was supported up to three weeks in a subsample of 221 participants (140 women, 81 men). Evidence of construct validity was demonstrated through positive associations with indices of psychological well-being and negative associations with indices of negative body image and disordered eating behaviours. Availability of a Brazilian Portuguese translation of the BAS-2 should help to promote greater understanding of positive body image in the Brazilian context.

Psychometric properties of the Breast Size Rating Scale (BSRS) in Brazilian university women.

The present study examined the psychometric properties of a Brazilian Portuguese translation of the Breast Size Rating Scale (BSRS). A total of 194 Brazilian university women completed the BSRS along with measures of body satisfaction, body appreciation, weight discrepancy, and attitudes toward societal appearance ideals. They also had their actual bra size and body mass indices (BMIs) objectively measured. Results indicated evidence of adequate convergent validity insofar as greater breast size dissatisfaction was significantly associated with greater weight discrepancy, higher BMI, lower body appreciation, lower body satisfaction, greater use of information from society about appearance ideals, greater perceived pressure from society about appearance ideals, and greater internalisation of general and athletic appearance ideals, respectively. In our sample, 20.6% of women reported no breast size dissatisfaction, 65.5% desired a larger breast size, and 13.9% desired a smaller breast size. Findings demonstrate that BSRS scores are psychometrically sound and that breast size dissatisfaction is common among Brazilian women.

[Relationship between body mass index and self-perception among university students]. / Relação entre índice de massa corporal e a percepção da auto-imagem em universitários.

OBJECTIVE: To assess the relationship between body mass index and self-perception of body image. METHODS: A study was carried out in a sample comprising 106 female and male university students aged 18 years or more in Ribeirão Preto, Southeastern Brazil, in 2003. The Contour Drawing Rating Scale and Visual Analogue Scale were used to evaluate body image perception; the former was applied using two different psychometric methods. A body image questionnaire was used to assess the subjective component of body image. Subjects were classified according to body mass index. Statistical analyses were performed through variance analysis and Newman-Keuls post-hoc test. RESULTS: Most normal weight or overweight women (87%) overestimated their body size while obese women and all men (73%), regardless of their BMI, underestimated their body size. The differences of body image perception between men and women were statistically significant as well as the overall dissatisfaction with their perceived body size, revealed by a desired lower body mass index. Overweight women were more concerned and uncomfortable with their own body. CONCLUSIONS: Both men and women had a distorted self-perception of body image, underestimating or overestimating it. The study results suggest dissatisfaction of subjects with their body image as they desire to have leaner bodies.

Early protein malnutrition changes learning and memory in spaced but not in condensed trials in the Morris water-maze.

Early protein malnutrition induces structural, neurochemical and functional changes in the central nervous system leading to alterations in cognitive and behavioral development of rats. The aim of the present study was to investigate the effects of protein malnutrition during lactation on acquisition and retention of spatial information using different training procedures (spaced x condensed trials). Rats treated with 16% (well-nourished) or 6% (malnourished) protein diets during the lactation phase and nutritionally recovered until 70 days of age were tested in the Morris water-maze in procedures of 1 trial/day (spaced trials), 4, 8, 12 trials/day (intermediate density) and 24 trials/day (condensed trials), completing 24 trials at the end of training. Seven and 28 days after the training the animals were tested again in just one trial to assess long-term memory. The results showed that protein malnutrition caused deficits on the spatial learning and memory in spaced but not in intermediate and condensed trials procedure. Seven and 28 days after the training there was an increase in the latency to find the platform but only malnourished animals submitted to 1 trial/day had significantly higher latency as compared with well-nourished controls. One of the possible hypotheses is that the effect protein malnutrition only in the procedure of spaced trials could be due to deficits in memory consolidation. It is suggested that these deficits can be the result of alterations produced by protein malnutrition in the hippocampal formation or in long-lasting emotional and/or motivational aspects of the rat's behavior.

Early postnatal protein malnutrition changes the development of social play in rats.

Early protein malnutrition produces structural and functional alterations in the brain and changes the organism-environment interactions. Rats from 26 to 76 days of age were used to study the effects of early postnatal protein malnutrition on the development of social play. During lactation phase the litters were fed diet containing 16% protein (well-nourished) or 6% protein (malnourished). From weaning to the end of behavioral tests well-nourished animals were fed a commercial lab chow diet (well-nourished--W) and the malnourished rats were divided into 2 groups: one was maintained on 6% protein diet (malnourished--M) and the other was fed a commercial lab chow diet (previously malnourished--PM). Pairs of male rats of same diet conditions were tested, at different ages, for three consecutive days. During sessions the following behaviors were recorded: pinning, wrestling, walk-over and rear. The frequency of wrestling and walk-over was significantly higher in malnourished as compared to well-nourished animals (p<0.05). Early protein malnutrition also changed the ontogeny of play behaviors (pinning and wrestling) with developmental retards in M and PM as compared with W animals, especially at 46 and 56 days of age. These results suggest that early protein malnutrition can affect the development of neural mechanisms underlying social play in rats.