Delayed Outgrowth in Response to the BDNF and Altered Synaptic Proteins in Neurons From SHR Rats.

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity symptoms. Neuroimaging studies have revealed a delayed cortical and subcortical development pattern in children diagnosed with ADHD. This study followed up on the development in vitro of frontal cortical neurons from Spontaneously hypertensive rats (SHR), an ADHD rat model, and Wistar-Kyoto rats (WKY), control strain, over their time in culture, and in response to BDNF treatment at two different days in vitro (DIV). These neurons were also evaluated for synaptic proteins, brain-derived neurotrophic factor (BDNF), and related protein levels. Frontal cortical neurons from the ADHD rat model exhibited shorter dendrites and less dendritic branching over their time in culture. While pro- and mature BDNF levels were not altered, the cAMP-response element-binding (CREB) decreased at 1 DIV and SNAP-25 decreased at 5 DIV. Different from control cultures, exogenous BDNF promoted less dendritic branching in neurons from the ADHD model. Our data revealed that neurons from the ADHD model showed decreased levels of an important transcription factor at the beginning of their development, and their delayed outgrowth and maturation had consequences in the levels of SNAP-25 and may be associated with less response to BDNF. These findings provide an alternative tool for studies on synaptic dysfunctions in ADHD. They may also offer a valuable tool for investigating drug effects and new treatment opportunities.

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.

Caffeine prevents neurodegeneration and behavioral alterations in a mice model of agitated depression.

Longitudinal and some experimental studies have showed the potential of caffeine to counteract some depressive behaviors and synaptic dysfunctions. In this study, we investigated the potential of caffeine in preventing behavioral outcomes, neurodegeneration and synaptic proteins alterations in a mice model of agitated depression by bilateral olfactory bulbectomy (OB). For this purpose, bulbectomized mice received caffeine (0.3 g/L and 1.0 g/L, drinking water), during the active cycle, for seven weeks (two before the surgery and throughout five weeks after OB). Caffeine prevented OB-induced hyperactivity and recognition memory impairment and rescue self care and motivational behavior. In the frontal cortex, bulbectomized mice presented increase in the adenosine A1 receptors (A1R) and GFAP, while adenosine A2A receptors (A2AR) increased in the hippocampus and striatum and SNAP-25 was decreased in frontal cortex and striatum. Caffeine increased A1R in the striatum of bulbectomized mice and in SHAM-water group caffeine increased A2AR in the striatum and decreased SNAP-25 in the frontal cortex. Astrogliosis observed in the polymorphic layer of the dentate gyrus of OB mice was prevented by caffeine as well as the neurodegeneration in the striatum and piriform cortex. Based on these behavioral and neurochemical evidences, caffeine confirms its efficacy in preventing neurodegeneration associated with memory impairment and may be considered as a promising therapeutic tool in the prophylaxis and/or treatment of depression.

Methylprednisolone as a memory enhancer in rats: Effects on aversive memory, long-term potentiation and calcium influx.

It is well recognized that stress or glucocorticoids hormones treatment can modulate memory performance in both directions, either impairing or enhancing it. Despite the high number of studies aiming at explaining the effects of glucocorticoids on memory, this has not yet been completely elucidated. Here, we demonstrate that a low daily dose of methylprednisolone (MP, 5mg/kg, i.p.) administered for 10-days favors aversive memory persistence in adult rats, without any effect on the exploring behavior, locomotor activity, anxiety levels and pain perception. Enhanced performance on the inhibitory avoidance task was correlated with long-term potentiation (LTP), a phenomenon that was strengthen in hippocampal slices of rats injected with MP (5mg/kg) during 10days. Additionally, in vitro incubation with MP (30-300µM) concentration-dependently increased intracellular [Ca2+]i in cultured hippocampal neurons depolarized by KCl (35mM). In conclusion, a low daily dose of MP for 10days may promote aversive memory persistence in rats.

Influência da diabetes e a prática de exercício físico e atividades cognitivas e recreativas sobre a função cognitiva e emotividade em grupos de terceira idade / Influence of diabetes and physical exercise, mental and recreational activities practice on the cognitive function and emotionality in aging groups

OBJETIVO: Neste estudo buscou-se verificar a influência da participação em atividades de grupos de terceira idade (GTI), envolvendo a prática de exercícios físicos e atividades cognitivas e recreativas, sobre a função cognitiva e aspectos emocionais, como ansiedade e depressão, de idosos diabéticos e não diabéticos. MÉTODOS: Participaram deste estudo descritivo transversal 158 idosos, subdivididos em quatro grupos: (1) idosos não participantes de GTI e não diabéticos; (2) idosos não participantes de GTI e diabéticos; (3) idosos participantes de GTI e não diabéticos; e (4) idosos participantes de GTI e diabéticos. Todos os idosos foram submetidos a um protocolo de avaliação cognitiva (Miniexame do Estado Mental-MEEM, Teste de Recordação Imediata e Tardia Livre de Palavras - RIP e RTP, respectivamente, e Teste de Reconhecimento de Faces Famosas-FF), ansiedade (IDATE) e depressão (Escala de Depressão Geriátrica-EGD). Para comparação entre os grupos, utilizou-se ANOVA de uma via para os dados paramétricos e teste de Kruskal-Wallis para os não paramétricos. RESULTADOS: Os idosos participantes do estudo tinham idade média de 72,63±6,84 anos (75% mulheres e 25% homens). Os resultados demonstraram que os idosos do grupo 2 (diabéticos e não participantes de GTI) apresentaram menores escores cognitivos do que os do grupo 3 (não diabéticos e participantes de GTI) (p=0,012 no MEEM; p=0,028 na RIP; p=0,011 na EGD). CONCLUSÃO: Pode-se afirmar que a associação da diabetes mellitus com um estilo de vida menos ativo, sem a prática de exercícios físicos e atividades recreativas e cognitivas, possivelmente representa um fator de risco para a aceleração das perdas cognitivas que acompanham o processo de envelhecimento. .

OBJECTIVE: This study aimed to determine the influence of participation in third age groups (TAG), involving the practice of physical exercise and cognitive and recreational activities, on cognitive function and emotional issues such as anxiety and depression in diabetic and non-diabetic elderly patients. METHODS: In this cross sectional study, participated 158 older adults divided into four groups: (1) elderly non-participants in TAG and non-diabetic; (2) elderly non-participants in TAG and diabetic; (3) elderly participants in TAG and non-diabetic; and (4) elderly participants in TAG and diabetic. All of them were submitted to a protocol of cognitive assessment (Mini-Mental State-MMSE, Immediate and Delayed Recall Test Free Words - RIP and RTP, and Recognition of Famous Faces Test-FF), anxiety (STAI) and depression (Geriatric Depression Scale-EGD). For comparison between groups, we used one-way ANOVA for parametric data and the Kruskal-Wallis test for non-parametric data. RESULTS: The mean age of the sample was 72.63±6.84 years old (75% women and 25% men). The results demonstrate that the elderly group 2 (diabetic and non-participants EG) have lower cognitive scores than group 3 (non-diabetic participants and EG) (p=0.012 in MMSE, p=0.028 in the IWR, p=0.011 in GDS). CONCLUSION: It can be argued that the association between diabetes mellitus and less active lifestyle, without the practice of physical exercise and recreational and cognitive activities, possibly represents a risk factor for the acceleration of cognitive losses that follow the aging process. .