Kinin B1 receptor deficiency protects mice fed by cafeteria diet from abnormal glucose homeostasis.

The kallikrein-kinin system has been implicated in body weight and glucose homeostasis. Their major effectors act by binding to the kinin B2 and B1 receptors. It was assessed the role of the kinin B1 receptor in weight and glucose homeostasis in B1 receptor knockout mice (B1RKO) subjected to a cafeteria diet (CAF). Wild-type (WT) and B1RKO male mice (C57BL/6 background; 8 weeks old) were fed a standard diet (SD) or CAF for 14 weeks, ad libitum, and four groups were formed: WT-SD; B1RKO-SD; WT-CAF; B1RKO-CAF. Body weight and food intake were assessed weekly. It was performed glucose tolerance (GTT) and insulin tolerance tests (ITT), and HOMA-IR, HOMA-ß and HOMA-ß* 1/HOMA-IR were calculated. Islets from WT and B1RKO were isolated in order to measure the insulin secretion. Western blot was used to assess the hepatic AKT phosphorylation and qPCR to assess gene expression. CAF induced a higher body mass gain in B1RKO compared to WT mice. CAF diet increased epididymal fat depot mass, hepatic fat infiltration and hepatic AKT phosphorylation in both genotypes. However, B1RKO mice presented lower glycemic response during GTT when fed with CAF, and a lower glucose decrease in the ITT. This higher resistance was overcomed with higher insulin secretion when stimulated by high glucose, resulting in higher glucose uptake in the GTT when submitted to CAF, despite lower insulin sensitivity. Islets from B1RKO delivered 4 times more insulin in 3-month-old mice than islets from WT. The higher insulin disposition index and high insulin delivery of B1RKO can explain the decreased glucose excursion during GTT. In conclusion, CAF increased the ß-cell function in B1RKO mice, compensated by the diet-induced insulin resistance and resulting in a healthier glycemic response despite the higher weight gain.

Behind teaching-learning strategies in physiology: perceptions of students and teachers of Brazilian medical courses.

The teaching-learning process must constantly overcome the barriers imposed by rapid scientific and technological advances, as well as changes in the profiles of students and access to information. This study intended to analyze the perceptions of students and professors of medical courses of the teaching-learning strategies used in physiology at different Brazilian universities as well as the factors that influence or hinder the learning of this discipline. Questionnaires were analyzed from 174 students and 16 professors of physiology from medical courses of 20 higher education institutions (public and private) in a southern Brazilian state. The teaching strategies most used by physiology teachers coincided with the classroom activities that students consider to have the greatest contribution to their learning (expository classes/lectures, tests and questionnaires, problem-based learning/clinical case studies, and demonstrative/practical classes). It was also evidenced that teachers' didactic is considered as a very influencing factor for the students during their learning process, whereas the teachers pointed out daily pedagogical practice as the most relevant factor in the development of their skills within the classroom. In addition, some factors hindering the teaching-learning process of physiology were identified by the respondents, such as large amounts of information, little time for study outside the classroom, previous knowledge, and intrinsic difficulty of the discipline. Finally, students tended to study alone and generally used teachers' slides and their own notes as study materials. The continuous assessment of the perceptions, needs, and difficulties of students and teachers plays an essential role in improving the teaching-learning process.

Long-Lasting Actions of Progesterone Protect the Neonatal Brain Following Hypoxia-Ischemia.

Neonatal hypoxia-ischemia (HI) is the leading cause of mortality and morbidity in newborns, occurring in approximately 2% of live births. Neuroprotective actions of progesterone (PROG) have already been described in animal models of brain lesions. However, PROG actions on neonates are still controversial. Here, we treated male Wistar rats exposed to HI with PROG. Five experimental groups were defined (n = 6/group) according to the scheme of PROG administration (10 mg/kg): SHAM (animals submitted to a fictitious surgery, without ischemia induction, and maintained under normoxia), HI (animals undergoing HI), BEFORE (animals undergoing HI and receiving PROG immediately before HI), AFTER (animals undergoing HI and receiving PROG at 6 and 24 h after HI) and BEFORE/AFTER (animals undergoing HI and receiving PROG immediately before and 6 and 24 h after HI). At P14 (7 days following HI), the volumes of lesion of the cerebral hemisphere and the hippocampus ipsilateral to the cerebral ischemia were evaluated, along with p-Akt, cleaved caspase-3 and GFAP expression in the hippocampus. PROG reduces the loss of brain tissue caused by HI. Moreover, when administered after HI, PROG was able to increase p-Akt expression and reduce both cleaved caspase-3 and GFAP expression in the hippocampus. In summary, it was possible to observe a neuroprotective action of PROG on the brain of neonatal animals exposed to experimental HI. This is the first study suggesting PROG-dependent Akt activation is able to regulate negatively cleaved caspase-3 and GFAP expression protecting neonatal hypoxic-ischemic brain tissue from apoptosis and reactive gliosis.

Pedagogical training profile of basic health sciences faculty in biomedical and related fields at Brazilian public and private higher education institutions.

Historically, Brazilian higher education teachers' pedagogical training has not been a concern. Even today, a graduate degree is the main requirement to be a faculty member. However, a set of competencies is necessary to teach: pedagogical competency, political competency, and knowledge of specific content. Most graduate training covers only knowledge of specific content. Therefore, this work aimed to outline the profile of basic health sciences faculty members teaching in biomedical and related fields regarding their undergraduate and graduate training, as well as the initial and continued pedagogical training in Brazilian public and private higher education institutions (HEIs). An electronic questionnaire was sent to these professionals, and a total of 763 responses were analyzed (66.4% from public and 33.6% from private HEIs). Compared with private HEI faculty, faculty from public HEIs were more experienced in teaching, and more time had passed since they finished their graduate training. On the other hand, faculty from private HEIs had a more intense undergraduate teaching workload than faculty from public HEIs. Additionally, faculty from private HEIs attended more extensive and more frequent pedagogical training activities (PTAs). Both groups expressed that activities closely related to their classroom practice and recognition for good pedagogical performance were incentives for their participation in PTAs. In conclusion, differences between the faculty from public and private HEIs may be due to the characteristics of HEIs themselves. Hypothetically, private HEIs focus on teaching, which may explain why faculty from these institutions seek improvement in this area, whereas public HEIs focus on research.

The metabolic and neuroinflammatory changes induced by consuming a cafeteria diet are age-dependent.

OBJECTIVES: To compare the effects of a palatable cafeteria diet on serum parameters and neuroinflammatory markers of young and aged female Wistar rats. METHODS: Three-month-old (young) and 18-month-old (aged) female Wistar rats had access to a cafeteria diet (Caf-Young, Caf-Aged) or a standard chow diet (Std-Young, Std-Aged). RESULTS: The Caf-Young group showed a higher food consumption, weight gain, visceral fat depot, serum insulin and leptin levels, and the insulin resistance index (HOMA-IR) than the Std-Young group. The Caf-Aged group exhibited an increase in interleukin-1 levels in the cerebral cortex and hippocampus. The number of GFAP-positive cells did not differ between the groups, but there was a diet effect in the cerebral cortex and an age effect in the hippocampus. Phospho-tau expression did not differ between the groups. DISCUSSION: The 3- and 18-month-old rats responded differently to a cafeteria diet. Insulin and leptin levels are elevated in young animals fed a cafeteria diet, whereas aged animals are prone to neuroinflammation (indicated by an increase in interleukin-1ß levels). A combination of hypercaloric diet and senescence have detrimental effects on the inflammatory response in the brain, which may predispose to neurological diseases.

Female rats are more susceptible to metabolic effects of dehydroepiandrosterone treatment.

Dehydroepiandrosterone (DHEA) is a steroid hormone that presents several effects on metabolism; however, most of the studies have been performed on male animals, while few authors have investigated possible sex differences regarding the metabolic effects of DHEA. Therefore, the aim of this study was to evaluate the effect of different doses of DHEA on metabolic parameters of male and ovariectomized female Wistar rats. Sex differences were found in the metabolism of distinct substrates and in relation to the effect of DHEA. In respect to the glucose metabolism in the liver, the conversion of glucose to CO2 and the synthesis of lipids from glucose were 53% and 33% higher, respectively, in males. Also, DHEA decreased hepatic lipogenesis only in females. Regarding the hepatic glycogen synthesis pathway, females presented 73% higher synthesis than males, and the effect of DHEA was observed only in females, where it decreased this parameter. In the adipose tissue, glucose uptake was 208% higher in females and DHEA decreased this parameter. In the muscle, glucose uptake was 168% higher in females and no DHEA effect was observed. In summary, males and females present a different metabolic profile, with females being more susceptible to the metabolic effects of DHEA.

Effects of progesterone on the neonatal brain following hypoxia-ischemia.

Progesterone displays a strong potential for the treatment of neonatal hypoxic-ischemic encephalopathy since it has been shown to be beneficial in the treatment of the central nervous system injuries in adult animals. Here, we evaluated the effects of the administration of progesterone (10 mg/kg) in seven-days-old male Wistar rats submitted to neonatal hypoxia-ischemia (HI). Progesterone was administered immediately before ischemia and/or 6 and 24 h after the onset of hypoxia. The body weight of the animals, the volume of brain lesion and the expression of p-Akt and procaspase-3 in the hippocampus were evaluated. All animals submitted to HI showed a reduction in the body weight. However, this reduction was more remarkable in those animals which received progesterone before surgery. Administration of progesterone was unable to reduce the volume of brain damage caused by HI. Moreover, no significant differences were observed in the expression of p-Akt and procaspase-3 in animals submitted to HI and treated with either progesterone or vehicle. In summary, progesterone did not show a neuroprotective effect on the volume of brain lesion in neonatal rats submitted to hypoxia-ischemia. Furthermore, progesterone was unable to modulate p-Akt and procaspase-3 signaling pathways, which may explain the absence of neuroprotection. On the other hand, it seems that administration of progesterone before ischemia exerts some systemic effect, leading to a remarkable reduction in the body weight.

Epitestosterone- and testosterone-replacement in immature castrated rats changes main testicular developmental characteristics.

Epitestosterone is the 17α-epimer of testosterone and has been described as an anti-androgen, since it inhibits the effects produced by testosterone and dihydrotestosterone via the nuclear androgen receptor (nAR). However, epitestosterone also displays an effect which is similar to the non-classical effect of testosterone, depolarizing the membrane potential of Sertoli cells and inducing a rapid Ca2+ uptake. This study aimed to investigate the effects of a treatment with epitestosterone on developmental parameters of immature rats. Animals were chemically castrated by using the gonadotropin-releasing hormone (GnRH) antagonist cetrorelix and then received a replacement of 7 days with epitestosterone or testosterone. Replacement with either epitestosterone or testosterone restored the anogenital distance (AGD) and testicular weight which had been reduced by chemical castration. The immunocontent of nAR and the nAR-immunoreactivity were reduced by epitestosterone treatment in the testis of both castrated and non-castrated animals. Furthermore, testosterone was unable of changing the membrane potential of Sertoli cells through its non-classical action in the group of animals castrated and replaced with epitestosterone. In conclusion, in relation to the level of protein expression of nAR epitestosterone acts as an anti-androgen. However, it acts in the same way as testosterone when genital development parameters are evaluated. Moreover, in castrated rats epitestosterone suppressed the non-classical response of testosterone, changing the pattern of testosterone signalling via a membrane mechanism in Sertoli cells.

Aversive and non-aversive memory impairment in the mucopolysaccharidosis II mouse model.

Hunter syndrome (MPS II, OMIM 309900) is a lysosomal storage disorder due to deficient iduronate sulphatase activity. Patients present multiple cognitive alterations, and the aim of this work was to verify if MPS II mice also present some progressive cognitive alterations. For that, MPS II mice from 2 to 6 months of age were submitted to repeated open field and inhibitory avoidance tests to evaluate memory parameters. MPS II mice presented impaired memory at 6 months evaluated by open field test. They also performed poorly in the inhibitory avoidance test from 4 months. We conclude that MPS II mice develop cognitive alterations as the disease progresses. These tests can be used in the future to study the efficacy of therapeutic approaches in the central nervous system.

Sex-specific effects of dehydroepiandrosterone (DHEA) on glucose metabolism in the CNS.

DHEA is a neuroactive steroid, due to its modulatory actions on the central nervous system (CNS). DHEA is able to regulate neurogenesis, neurotransmitter receptors and neuronal excitability, function, survival and metabolism. The levels of DHEA decrease gradually with advancing age, and this decline has been associated with age related neuronal dysfunction and degeneration, suggesting a neuroprotective effect of endogenous DHEA. There are significant sex differences in the pathophysiology, epidemiology and clinical manifestations of many neurological diseases. The aim of this study was to determine whether DHEA can alter glucose metabolism in different structures of the CNS from male and female rats, and if this effect is sex-specific. The results showed that DHEA decreased glucose uptake in some structures (cerebral cortex and olfactory bulb) in males, but did not affect glucose uptake in females. When compared, glucose uptake in males was higher than females. DHEA enhanced the glucose oxidation in both males (cerebral cortex, olfactory bulb, hippocampus and hypothalamus) and females (cerebral cortex and olfactory bulb), in a sex-dependent manner. In males, DHEA did not affect synthesis of glycogen, however, glycogen content was increased in the cerebral cortex and olfactory bulb. DHEA modulates glucose metabolism in a tissue-, dose- and sex-dependent manner to increase glucose oxidation, which could explain the previously described neuroprotective role of this hormone in some neurodegenerative diseases.

Effects of isolated vitamin B6 supplementation on oxidative stress and heart function parameters in experimental hyperhomocysteinemia

Introduction: The purpose of this study was to investigate the effects of isolated vitamin B6 (VB6 ) supplementation on experimental hyperhomocysteinemia (Hhe) induced by homocysteine thiolactone (HcyT). Methods: Fifteen male Wistar rats were divided into three groups according to their treatment. Animals received water and food ad libitum and an intragastric probe was used to administer water for 60 days (groups: CB6, HcyT, and HB6 ). On the 30th day of treatment, two groups were supplemented with VB6 in the drinking water (groups: CB6 and HB6 ). After 60 days of treatment, homocysteine (Hcy), cysteine, and hydrogen peroxide concentration, nuclear factor (erythroid-derived 2)-like 2 (NRF2) and glutathione S-transferase (GST) immunocontent, and superoxide dismutase (SOD), catalase (CAT), and GST activities were measured. Results: The HcyT group showed an increase in Hcy concentration (62%) in relation to the CB6 group. Additionally, GST immunocontent was enhanced (51%) in the HB6 group compared to the HcyT group. Also, SOD activity was lower (17%) in the HB6 group compared to the CB6 group, and CAT activity was higher in the HcyT group (53%) compared to the CB6 group. Ejection fraction (EF) was improved in the HB6 group compared to the HcyT group. E/A ratio was enhanced in the HB6 group compared to the CB6 group. Correlations were found between CAT activity with myocardial performance index (MPI) (r = 0.71; P = 0.06) and E/A ratio (r = 0.6; P = 0.01), and between EF and GST activity (r = 0.62; P = 0.02). Conclusions: These findings indicate that isolated VB6 supplementation may lead to the reduction of Hcy concentration and promotes additional benefits to oxidative stress and heart function parameters (AU)

Dehydroepiandrosterone protects male and female hippocampal neurons and neuroblastoma cells from glucose deprivation.

Dehydroepiandrosterone (DHEA) modulates neurogenesis, neuronal function, neuronal survival and metabolism, enhancing mitochondrial oxidative capacity. Glucose deprivation and hypometabolism have been implicated in the mechanisms that mediate neuronal damage in neurological disorders, and some studies have shown that these mechanisms are sexually dimorphic. It was also demonstrated that DHEA is able to attenuate the hypometabolism that is related to some neurodegenerative diseases, eliciting neuroprotective effects in different experimental models of neurodegeneration. The aim of this study was to evaluate the effect of DHEA on the viability of male and female hippocampal neurons and SH-SY5Y neuroblastoma cells exposed to glucose deprivation. It was observed that after 12h of pre-treatment, DHEA was able to protect SH-SY5Y cells from glucose deprivation for 6h (DHEA 10(-12), 10(-8) and 10(-6)M) and 8h (DHEA 10(-8)M). In contrast, DHEA was not neuroprotective against glucose deprivation for 12 or 24h. DHEA (10(-8)M) also protected SH-SY5Y cells when added together or even 1h after the beginning of glucose deprivation (6h). Furthermore, DHEA (10(-8)M) also protected primary neurons from both sexes against glucose deprivation. In summary, our findings indicate that DHEA is neuroprotective against glucose deprivation in human neuroblastoma cells and in male and female mouse hippocampal neurons. These results suggest that DHEA could be a promising candidate to be used in clinical studies aiming to reduce neuronal damage in people from both sexes.

Astrocytes as a target for neuroprotection: Modulation by progesterone and dehydroepiandrosterone.

Stroke and traumatic injuries of the brain and spinal cord are major public health issues. In the last few decades, hundreds of clinical trials with patients suffering from these conditions have been done, however, most of them had not succeeded and there is still the need to develop more effective treatments for these conditions. Astrocytes play critical roles in the development, function and survival of neurons in the central nervous system. These cells are implicated in the pathophysiology and in the response to several neuropathological conditions and may represent potential cell targets for neuroprotective strategies. Progesterone and dehydroepiandrosterone (DHEA) are neuroactive steroids that modulate neuronal and astroglial function and have neuroprotective effects in different experimental models, being potential candidates to the development of new therapeutic approaches for brain and spinal cord injuries. The aim of this review is to discuss the role of astrocytes in the pathophysiology of brain and spinal cord injuries and how they could be modulated by progesterone and DHEA for the treatment of these conditions.

DHEA administration modulates stress-induced analgesia in rats.

An important aspect of adaptive stress response is the pain response suppression that occurs during or following stress exposure, which is often referred to as acute stress-induced analgesia. Dehydroepiandrosterone (DHEA) participates in the modulation of adaptive stress response, changing the HPA axis activity. The effect of DHEA on the HPA axis activity is dependent on the state and uses the same systems that participate in the regulation of acute stress-induced analgesia. The impact of DHEA on nociception has been studied; however, the effect of DHEA on stress-induced analgesia is not known. Thus, the aim of the present study was to evaluate the effect of DHEA on stress-induced analgesia and determine the best time for hormone administration in relation to exposure to stressor stimulus. The animals were stressed by restraint for 1h in a single exposure and received treatment with DHEA by a single injection before the stress or a single injection after the stress. Nociception was assessed with a tail-flick apparatus. Serum corticosterone levels were measured. DHEA administered before exposure to stress prolonged the acute stress-induced analgesia. This effect was not observed when the DHEA was administered after the stress. DHEA treatment in non-stressed rats did not alter the nociceptive threshold, suggesting that the DHEA effect on nociception is state-dependent. The injection of DHEA had the same effect as exposure to acute stress, with both increasing the levels of corticosterone. In conclusion, acute treatment with DHEA mimics the response to acute stress indexed by an increase in activity of the HPA axis. The treatment with DHEA before stress exposure may facilitate adaptive stress response, prolonging acute stress-induced analgesia, which may be a therapeutic strategy of interest to clinics.

Sweet taste of saccharin induces weight gain without increasing caloric intake, not related to insulin-resistance in Wistar rats.

In a previous study, we showed that saccharin can induce weight gain when compared with sucrose in Wistar rats despite similar total caloric intake. We now question whether it could be due to the sweet taste of saccharin per se. We also aimed to address if this weight gain is associated with insulin-resistance and to increases in gut peptides such as leptin and PYY in the fasting state. In a 14 week experiment, 16 male Wistar rats received either saccharin-sweetened yogurt or non-sweetened yogurt daily in addition to chow and water ad lib. We measured daily food intake and weight gain weekly. At the end of the experiment, we evaluated fasting leptin, glucose, insulin, PYY and determined insulin resistance through HOMA-IR. Cumulative weight gain and food intake were evaluated through linear mixed models. Results showed that saccharin induced greater weight gain when compared with non-sweetened control (p = 0.027) despite a similar total caloric intake. There were no differences in HOMA-IR, fasting leptin or PYY levels between groups. We conclude that saccharin sweet taste can induce mild weight gain in Wistar rats without increasing total caloric intake. This weight gain was not related with insulin-resistance nor changes in fasting leptin or PYY in Wistar rats.

Sex-related differences in the effects of high-fat diets on DHEA-treated rats.

Several studies have investigated the beneficial effects of dehydroepiandrosterone (DHEA) on lipid and glucose metabolism. However, many of these studies are inconclusive about the effects of DHEA administration on metabolic disorders, and there appear to be sex-related differences in the effects of DHEA treatment. Few animal studies have addressed the effects of DHEA on diet-induced metabolic disorders. The present study sought to ascertain whether sex differences exist in the effects of a high-fat diet (HFD) on weight gain, adiposity, and biochemical and hormonal parameters in DHEA-treated rats. Rats were fed a HFD for 4 weeks and simultaneously received treatment with DHEA (10 mg/kg by subcutaneous injection) once weekly. Body weight, retroperitoneal fat depot weight, serum glucose, insulin, and leptin levels, and hepatic lipids were measured. HFD exposure increased the adiposity index in both sexes, the hepatic triglyceride content in both sexes, and the hepatic total cholesterol level in males. Moreover, the HFD induced an increase in blood glucose levels in both sexes, and hyperinsulinemia in males. In this experimental model, DHEA treatment reduced hepatic triglyceride levels only in females, regardless of HFD exposure. Exposure to a HFD, even if it does not cause obesity, may enhance risk factors for metabolic disorders, and males are more sensitive to this effect. DHEA treatment can help prevent metabolic derangements, but its effect varies with sex.

Asymmetric effects of low doses of progesterone on GABA(A) receptor α4 subunit protein expression in the olfactory bulb of female rats.

The aim of this study was to evaluate the effect of progesterone on the protein expression of α4 subunit of GABA(A) receptor, serotonin transporter (SERT), Akt, Erk, and caspase-3 in the olfactory bulb (OB) of female rats exposed to the forced swimming test (FST). Female rats were injected daily with progesterone (0.4 mg/kg body mass) or vehicle during 2 complete oestrous cycles and exposed to the FST, and the protein expression of GABA(A) receptor α4 subunit, SERT, Akt, Erk, and caspase-3 in the OB were evaluated. Progesterone increased the expression of the α4 subunit in the right OB and decreased its expression in the left OB, although it did not change the expression of other proteins. In summary, our findings indicate that progesterone has an asymmetric modulatory effect on the expression of GABA(A) receptor α4 subunit in the OB. This effect could be related to the antidepressant-like effect of progesterone in female rats.

Satisfação, Percepção de Aprendizagem e Desempenho em Vídeo aula e Aula Expositiva / Satisfaction, Perceived Learning and Performance in Video Lesson andLecture

Educadores têm se perguntado sobre estratégias adequadas para interagir com uma geração de alunos que tem acesso a modernos meios de comunicação liderados pela Internet. Este estudo comparou dois grupos de alunos de graduação,um exposto a uma aula expositiva (AE, n=81) e o outro a uma vídeo-aula (VA, n=60), avaliando o desempenho (DES) em pré e pós-testes, satisfação(SAT) e percepção de aprendizagem (PA). Foram analisadas correlações entre SAT e PA e entre ambase o DES. Houve melhora de DES (teste de Wilcoxon)de ambos os grupos, sem diferença entre eles (testede Mann-Whitney); os alunos ficaram satisfeitos e expressaram boa percepção de aprendizagem(teste de Qui-Quadrado); houve correlação entre SAT e PA, e as correlações entre SAT e DES e entre PA e DES foram significativas, porém baixas (teste de correlação de Spearman). Conclui-se que VAe AE são adequadas e promovem aprendizado dos alunos que se sentiram satisfeitos e com a percepção de que aprenderam o conteúdo. Sugere seque as metodologias possam ser utilizadas pelo professor de forma complementar, ressaltando a importância da construção de diálogos que sintonizem metodologias clássicas de ensino, como a aula expositiva, com novas tecnologias, como a vídeo-aula, que possam ser utilizadas com fins educacionais

Satisfação, Percepção de Aprendizagem e Desempenho em Vídeo aula e Aula Expositiva / Satisfaction, Perceived Learning and Performance in Video Lesson andLecture

Educadores têm se perguntado sobre estratégias adequadas para interagir com uma geração de alunos que tem acesso a modernos meios de comunicação liderados pela Internet. Este estudo comparou dois grupos de alunos de graduação,um exposto a uma aula expositiva (AE, n=81) e o outro a uma vídeo-aula (VA, n=60), avaliando o desempenho (DES) em pré e pós-testes, satisfação(SAT) e percepção de aprendizagem (PA). Foram analisadas correlações entre SAT e PA e entre ambase o DES. Houve melhora de DES (teste de Wilcoxon)de ambos os grupos, sem diferença entre eles (testede Mann-Whitney); os alunos ficaram satisfeitos e expressaram boa percepção de aprendizagem(teste de Qui-Quadrado); houve correlação entre SAT e PA, e as correlações entre SAT e DES e entre PA e DES foram significativas, porém baixas (teste de correlação de Spearman). Conclui-se que VAe AE são adequadas e promovem aprendizado dos alunos que se sentiram satisfeitos e com a percepção de que aprenderam o conteúdo. Sugere seque as metodologias possam ser utilizadas pelo professor de forma complementar, ressaltando a importância da construção de diálogos que sintonizem metodologias clássicas de ensino, como a aula expositiva, com novas tecnologias, como a vídeo-aula, que possam ser utilizadas com fins educacionais.

Educators have been wondering about the mostappropriate strategies to interact with a generationof students who has access to modern means ofcommunication, led by the Internet. This studycompared two groups of undergraduate students,one exposed to a lecture (L, n=81) and the otherto a video lesson (VL, n=60) through performanceevaluation (PER) in pre- and post-tests, satisfaction(SAT) and perceived learning (PL). The correlationsbetween SAT and PL and between both and PER wereanalyzed. The data showed an improvement of PER(Wilcoxon test) in both groups, without differencebetween them (Mann-Whitney test); both groups ofstudents were satisfied and perceived good sense oflearning (Chi-Square test); there was a correlationbetween SAT and PL and the correlation between SATand DES and between DES and PA were significant,but low (Spearman test). In conclusion, L and VL areappropriate and promote learning and the studentsfelt satisfied and with the perception that theylearned the content of the subject. It is suggestedthat both methodologies can be used by the teacheras a reinforcement and in a complementary manner,emphasizing the importance of constructing dialogicbridges able to match classical teaching methodssuch as lecturing with new technologies, as the videolesson, that can be used for educational purposes.

Effect of low doses of progesterone in the expression of the GABA(A) receptor α4 subunit and procaspase-3 in the hypothalamus of female rats.

Progesterone is a steroid which regulates neural function, thereby modulating neurotransmission, cell survival, and behavior. Previous studies by our group have shown that chronic administration of low doses of progesterone in diestrus II female rats has an antidepressant-like effect in the forced swimming test (FST). Depression is associated with the several neurotransmitters systems, including GABA and serotonin, and with neurodegeneration and cell death in some brain circuits. The aim of this study was to verify the effect of progesterone on the protein expression of the GABA(A) receptor α4 subunit, serotonin transporter (SERT), Akt, extracellular signal-regulated kinase (Erk), and caspase-3 in the hypothalamus of diestrus II female rats exposed to the FST. Female rats were treated with a daily injection of progesterone (0.4 mg/kg) or vehicle, during two complete oestrous cycles. On the day of the experiment, the animals were euthanized 30 min after the FST, the hypothalamus was dissected and protein expression of GABA(A) receptor α4 subunit, SERT, Akt, Erk, and caspase-3 was evaluated. Progesterone increased the expression of GABA(A) receptor α4 subunit but did not change the expression of SERT. Progesterone decreased the expression of procaspase-3 in the hypothalamus without changing the activation of Akt and Erk in this structure. In summary, our results suggest that progesterone acts to increase the expression of the GABA(A) receptor α4 subunit and decrease the expression of procaspase-3 in the hypothalamus of female rats. Such effects may be involved in the antidepressant-like effect of progesterone in female rats exposed to the FST.