Caroline Dalla Colletta Altermann

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.

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

&NA; 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. HighlightsWhite, green and red teas protect recognition memory deficit after ischemic stroke.Only green tea protects against ischemic stroke induced spatial memory deficit.Only green tea protects against hippocampal oxidative stress after ischemic stroke.Neuroprotection is higher after green tea supplementation.

Physical exercise prevents motor disorders and striatal oxidative imbalance after cerebral ischemia-reperfusion.

Stroke is the third most common cause of death worldwide, and most stroke survivors present some functional impairment. We assessed the striatal oxidative balance and motor alterations resulting from stroke in a rat model to investigate the neuroprotective role of physical exercise. Forty male Wistar rats were assigned to 4 groups: a) control, b) ischemia, c) physical exercise, and d) physical exercise and ischemia. Physical exercise was conducted using a treadmill for 8 weeks. Ischemia-reperfusion surgery involved transient bilateral occlusion of the common carotid arteries for 30 min. Neuromotor performance (open-field and rotarod performance tests) and pain sensitivity were evaluated beginning at 24 h after the surgery. Rats were euthanized and the corpora striata was removed for assay of reactive oxygen species, lipoperoxidation activity, and antioxidant markers. Ischemia-reperfusion caused changes in motor activity. The ischemia-induced alterations observed in the open-field test were fully reversed, and those observed in the rotarod test were partially reversed, by physical exercise. Pain sensitivity was similar among all groups. Levels of reactive oxygen species and lipoperoxidation increased after ischemia; physical exercise decreased reactive oxygen species levels. None of the treatments altered the levels of antioxidant markers. In summary, ischemia-reperfusion resulted in motor impairment and altered striatal oxidative balance in this animal model, but those changes were moderated by physical exercise.

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.

The inclusion of undergraduate students in physiology outreach activities improves their physiology learning and understanding skills

the traditional teaching method using expositive class has limitations, as the only way of knowledge transmission relies on the relationship between teacher/professor and student, and because of this, several ways of teaching and elucidation of the contents have been discussed ([1][1], [2][2]). The

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.

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.

PERFIL COGNITIVO DE IDOSOS INSTITUCIONALIZADOS DE URUGUAIANA/RS

O processo de envelhecimento e acompanhado por uma serie de alteracoes psicossociais e biologicas, dentre as quais esta incluido o declinio cognitivo. Dependendo das condicoes de vida, atividades realizadas e interacoes sociais do idoso, o declinio cognitivo pode ser acelerado ou retardado. O objetivo deste trabalho foi avaliar o perfil cognitivo 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, a Escala Geriatrica de Depressao e o IDATE traco/estado. Os resultados apontaram para a presenca de declinio cognitivo em 40% dos idosos avaliados, indicios de depressao em 60% deles etendencia ao desenvolvimento de ansiedade. Estes resultados devem estar relacionados ao estilo de vida adotado pela maioria dos idosos institucionalizados e pelo abandono por parte da familia, muito comum nos casos de institucionalizacao;estas situacoes costumam colaborar para a aceleracao do declinio cognitivo.

VELHICE E ENVELHECER: Percepções de Idosos Institucionalizados de Uruguaiana/RS Acerca do Envelhecimento Humano

O objetivo deste trabalho e verificar as percepcoes de idosos institucionalizados de Uruguaiana/RS sobre o envelhecimento humano. A amostra foi composta por 9 idosos que vivem em uma instituicao voltada ao cuidado de idosos em Uruguaiana. Os idosos que concordaram participar responderam a um questionario de identificacao e, em seguida, realizaram uma avaliacao cognitiva geral atraves do Mini-Exame do Estado Mental (MEEM). Apos, foi realizada uma entrevista em profundidade, atraves de um questionario semi-estruturado. As entrevistas foram gravadas e posteriormente transcritas. O material foi lido, explorado e agregado em categorias. Verificou-se que as percepcoes dos idosos institucionalizados de Uruguaiana/RS sao norteadas por ideias relacionadas a concepcao biologica do envelhecimento, tambem predominante em nossa sociedade. O envelhecimento nao e pensado ou programado previamente, os idosos o veem como um processo natural, mas que traz consigo inumeros aspectos negativos, entre os quais destacam-se as perdas (de funcoes fisiologicas, da beleza, da saude fisica e mental) e a tristeza, relacionada ao abandono e a solidao.