Home-based vs. laboratory-based practical activities in the learning of human physiology: the perception of students.

Different tools have been used to facilitate the teaching and learning process in different areas of knowledge. Practical activities represent a form of teaching in which students not only listen to theoretical concepts but are also able to link theory and practice, and their importance in the biological sciences is notable. Sometimes, however, there is neither the time nor the resources to promote laboratory practices in physiology classes. In this sense, home-based practical activities may be an interesting alternative. Here, different approaches of practical activities were used and students' perceptions of the contributions of home-based practical activities (HBPA) and laboratory-based practical activities (LBPA) for physiology learning were collected. After each approach, the students evaluated the activities through an anonymous questionnaire. A total of 49 students completed the questionnaires, and the results demonstrate that both HBPA and LBPA were considered important contributors to physiology learning but that this contribution was more significant in the case of LBPA (χ2 = 4.356, P = 0.037).

Observing and understanding arterial and venous circulation differences in a physiology laboratory activity.

The purpose of the present article is to describe three simple practical experiments that aim to observe and discuss the anatomic and physiological functions and differences between arteries and veins as well as the alterations observed in skin blood flow in different situations. For this activity, students were divided in small groups. In each group, a volunteer is recruited for each experiment. The experiments only require a sphygmomanometer, rubber bands, and a clock and allow students to develop a hypothesis to explain the different responses to the interruption of arterial and venous blood flow. At the end, students prepare a short report, and the results are discussed. This activity allows students to perceive the presence of physiology in their daily lives and helps them to understand the concepts related to the cardiovascular system and hemodynamics.

Memory deficits and oxidative stress in cerebral ischemia-reperfusion: neuroprotective role of physical exercise and green tea supplementation.

Ischemic stroke is a major cause of morbidity and mortality all over the world. Among impairments observed in survivors there is a significant cognitive learning and memory deficit. Neuroprotective strategies are being investigated to minimize such deficits after an ischemia event. Here we investigated the neuroprotective potential of physical exercise and green tea in an animal model of ischemia-reperfusion. Eighty male rats were divided in 8 groups and submitted to either transient brain ischemia-reperfusion or a sham surgery after 8 weeks of physical exercise and/or green tea supplementation. Ischemia-reperfusion was performed by bilateral occlusion of the common carotid arteries during 30 min. Later, their memory was evaluated in an aversive and in a non-aversive task, and hippocampus and prefrontal cortex were removed for biochemical analyses of possible oxidative stress effects. Ischemia-reperfusion impaired learning and memory. Reactive oxygen species were increased in the hippocampus and prefrontal cortex. Eight weeks of physical exercise and/or green tea supplementation before the ischemia-reperfusion event showed a neuroprotective effect; both treatments in separate or together reduced the cognitive deficits and were able to maintain the functional levels of antioxidant enzymes and glutathione.

Short-term green tea supplementation prevents recognition memory deficits and ameliorates hippocampal oxidative stress induced by different stroke models in rats.

This study investigated the effect of green tea (GT) on short and long term declarative memory and oxidative damage induced by transient ischemia-reperfusion (IR) and intracerebral hemorrhage (ICH) in rats. Male Wistar rats were divided into 8 groups of 10 according the stroke type induced: Sham IR, Sham IR+GT, IR, IR+GT, Sham ICH, Sham ICH+GT, ICH, ICH+GT. Supplementation with GT was initiated 10days before stroke surgery and continuous for 6days after (GT dose 400mg/kg). Short (STM) and long term memory (LTM) we evaluated with object recognition task (OR) and hippocampus were used to evaluate parameters related to oxidative stress (ROS, lipid peroxidation and total antioxidant capacity). The rats subjected to IR and ICH showed STM and LTM deficits and GT intervention prevented it in both stroke models. IR and ICH induced increase on ROS levels in hippocampus. ICH increased the lipid peroxidation in hippocampus and the GT supplementation avoided it. IR induced decrease on total antioxidant capacity and GT prevented it. These results reveal that GT supplementation presents a neuroprotective role, attenuates redox imbalance and might have a beneficial impact on cognitive function after stroke.

Supplementation with different teas from Camellia sinensis prevents memory deficits and hippocampus oxidative stress in ischemia-reperfusion.

Memory and cognition impairments resultant of ischemic stroke could be minimized or avoided by antioxidant supplementation. In this regard, the neuroprotective potential of Green tea from Camellia sinensis has been investigated. However, there is a lack of information regarding the neuroprotective potential of others teas processed from the Camellia sinensis. Here we investigate the neuroprotective role of green, red, white and black tea on memory deficits and brain oxidative stress in a model of ischemic stroke in rats. Our findings show that green and red teas prevent deficits in object and social recognition memories, but only green tea protects against deficits in spatial memory and avoids hippocampal oxidative status and intense necrosis and others alterations in the brain tissue. In summary, green tea shows better neuroprotection in ischemic stroke than the others teas from Camellia sinensis.

Ameliorative effects of egg white hydrolysate on recognition memory impairments associated with chronic exposure to low mercury concentration.

The study aimed to investigate whether the Egg White Hydrolysate (EWH) is able to prevent the recognition memory disorders associated with long-term Hg exposure in rats. For this, male Wistar rats were treated for 60 days with: a) Untreated: saline solution (i.m.); b) Hydrolysate: EWH (1 g/kg/day, gavage); c) Mercury: HgCl2 (1st dose 4.6 µg/kg, subsequent doses 0.07 µg/kg/day, i.m.); d) Hydrolysate-Mercury. Object recognition memory test was performed to verify Short (STM) and Long-Term Memory (LTM) and Open Field, Plus Maze and Tail Flick tests were performed as control for behavioural experiments. Reactive Oxygen Species (ROS) in the hippocampus were determined by the dichlorofluorescein diacetate (DCFH-DA) method, malondialdehyde (MDA) levels by TBARS, antioxidant power by FRAP assay and total Hg concentration by atomic fluorescence spectrometry. We confirm that the STM and LTM were impaired in adult rats exposed to Hg at low concentrations, which may be related to the increased metal deposition, ROS production and subsequent oxidative damage in the hippocampus. In addition, we demonstrated for the first time that EWH treatment is able to prevent memory impairment induced by Hg exposure, reducing Hg content and ROS production in the hippocampus. In conclusion, EWH prevents memory impairments induced by chronic exposure to low doses of Hg. These findings may represent a good public health strategy since they indicate that EWH is a promising candidate as a new natural therapy for heavy metal intoxication.

Influence of mental practice and movement observation on motor memory, cognitive function and motor performance in the elderly.

BACKGROUND: With aging, it is important to maintain cognitive and motor functions to ensure autonomy and quality of life. During the acquisition of motor skills, it is necessary for the elderly to understand the purpose of the proposed activities. Physical and mental practice, as well as demonstrations, are strategies used to learn movements. OBJECTIVES: To investigate the influence of mental practice and the observation of movement on motor memory and to understand the relationship between cognitive function and motor performance in the execution of a sequence of digital movements in the elderly. METHOD: This was a cross-sectional study conducted with 45 young and 45 aged subjects. The instruments used were Mini-Mental State Examination (MMSE), Manual Preference Inventory and a Digital Motor Task (composed of a training of a sequence of movements, an interval and a test phase). The subjects were divided into three subgroups: control, mental practice and observation of movement. RESULTS: The elderly depend more strongly on mental practice for the acquisition of a motor memory. In comparing the performances of people in different age groups, we found that in the elderly, there was a negative correlation between the MMSE score and the execution time as well as the number of errors in the motor task. CONCLUSIONS: For the elderly, mental practice can advantage motor performance. Also, there is a significant relationship between cognitive function, learning and the execution of new motor skills.

Avaliação das funções cognitivas, qualidade de sono, tempo de reação e risco de quedas em idosos institucionalizados / Evaluation of cognitive functions, quality of sleep, reaction time and risk of falls in institucionalized elderly

O processo de envelhecimento e acompanhado por uma serie de alterações psicossociais e biológicas, dentre as quais esta incluído o declínio cognitivo. Dependendo das condições genéticas, estilo de vida, atividades e interações sociais do idoso, o declínio pode ser acelerado ou retardado. O objetivo deste trabalho foi avaliar o perfil cognitivo, o tempo de reação, o risco de quedas e a qualidade do sono de idosos institucionalizados da cidade de Uruguaiana-RS. Foram avaliados 10 idosos de ambos os sexos utilizando como instrumentos o Mini-Exame do Estado Mental (MEEM), a Escala de Depressão Geriátrica (EDG), o Inventario de Ansiedade Traco-Estado, o Teste de Tempo de Reação (TTR), a Escala de Eficácia de Quedas (EEQ) e o Índice de Qualidade de Sono de Pittsburgh (IQSP). Os resultados apontaram a presença de declínio cognitivo em 40% dos idosos, indícios de depressão em 60% deles e tendência ao desenvolvimento de ansiedade. 76% dos idosos classificaram a qualidade de seu sono como boa, mencionando alguns fatores que interferem na mesma, e 64% revelaram haver preocupação ou medo de cair. No TTR os idosos apresentaram escore médio de 2,175+- 0,32 s. Estes resultados podem estar relacionados ao estilo de vida adotado pela maioria dos idosos institucionalizados, fora do seu convívio familiar, favorecendo seu isolamento e sua inatividade física e mental, gerando declínio da capacidade cognitiva. Nossos resultados demonstram um percentual significativo de risco de demência, depressão e/ou ansiedade nos idosos institucionalizados avaliados.

The aging process is accompanied by a series of biological and psychosocial changes, among which is included cognitive decline. Depending on genetics, conditions of life, activities and social interactions of the elderly, the decline can be accelerated or decelerated. The objective of this work was evaluate the cognitive profile, the reaction time, the risk of falls and the quality of sleep of institutionalized elderly of Uruguaiana-RS. We evaluated 10 elderly of both sexes using as instruments the Mini-Mental State Examination, the Geriatric Depression Scale, the State-Trait Anxiety Inventory, the Reaction Time Test, the Falls Efficacy Scale and the Pittsburgh Sleep Quality Index. The results indicated presence of cognitive decline in 40% of elderly, signs of depression in 60% and tendency to the development of anxiety. 76% of elderly rated their quality of sleep as good, mentioning some factors that interfere in it, and 64% of the elderly revealed they have concern or fear of falling. In the reaction time score the elderly showed a mean of 2.175 + - 0.32 s. These results might be related to the lifestyle adopted by most of the institutionalized elderly, out of their family context, often contributing to their isolation and their physical/mental inactivity, generating cognitive decline. Our results demonstrate a significant percentage of risk of dementia, depression and/or anxiety in evaluated institutionalizated elderly.

Influence of mental practice and movement observation on motor memory, cognitive function and motor performance in the elderly / Influência da prática mental e observação do movimento sobre a memória motora, função cognitiva e desempenho motor em idosos

BACKGROUND: With aging, it is important to maintain cognitive and motor functions to ensure autonomy and quality of life. During the acquisition of motor skills, it is necessary for the elderly to understand the purpose of the proposed activities. Physical and mental practice, as well as demonstrations, are strategies used to learn movements. OBJECTIVES: To investigate the influence of mental practice and the observation of movement on motor memory and to understand the relationship between cognitive function and motor performance in the execution of a sequence of digital movements in the elderly. METHOD: This was a cross-sectional study conducted with 45 young and 45 aged subjects. The instruments used were Mini-Mental State Examination (MMSE), Manual Preference Inventory and a Digital Motor Task (composed of a training of a sequence of movements, an interval and a test phase). The subjects were divided into three subgroups: control, mental practice and observation of movement. RESULTS: The elderly depend more strongly on mental practice for the acquisition of a motor memory. In comparing the performances of people in different age groups, we found that in the elderly, there was a negative correlation between the MMSE score and the execution time as well as the number of errors in the motor task. CONCLUSIONS: For the elderly, mental practice can advantage motor performance. Also, there is a significant relationship between cognitive function, learning and the execution of new motor skills. .

CONTEXTUALIZAÇÃO: Com o envelhecimento, é importante a manutenção da função motora e cognitiva para garantir autonomia e qualidade de vida. Durante a aquisição de habilidades motoras é necessário que o idoso seja capaz de compreender o objetivo das atividades propostas e, para isso, a prática física e mental, assim como a demonstração, são estratégias usadas para o indivíduo aprender os movimentos. OBJETIVOS: Verificar a influência da prática mental e da observação do movimento sobre a memória motora e a relação entre a função cognitiva e o desempenho motor na execução de uma sequência de movimentos digitais em idosos. MÉTODO: Estudo transversal, realizado com 45 jovens e 45 idosos. Foram utilizados: Miniexame do Estado Mental (MEEM); Inventário de Preferência Manual de Edinburgh e Tarefa Motora Digital (composta por fase de treino, intervalo e teste). Os sujeitos foram divididos em três subgrupos: controle, prática mental e observação do movimento. RESULTADOS: Observou-se que idosos parecem depender mais da prática mental para a aquisição de uma memória motora e, na comparação do desempenho entre as faixas etárias, houve diferença no tempo de execução; nos idosos, observou-se correlação negativa entre o escore do MEEM e o tempo de execução e o número de erros na tarefa motora. CONCLUSÕES: Para idosos, a prática mental parece favorecer o desempenho motor, assim como existe uma relação significativa entre a função cognitiva e o aprendizado e execução de novas habilidades motoras. .