Memantine mediates astrocytic activity in response to excitotoxicity induced by PP2A inhibition.

Reduced activity of protein phosphatase 2 A (PP2A) is a common feature in Alzheimer's disease (AD) and non-AD tauopathies. The administration of okadaic acid (OKA), a potent PP2A and PP1 inhibitor, is a common research tool for inducing AD-like alterations such as tau hyperphosphorylation and cognitive decline. Recently, we showed that OKA increases cerebrospinal fluid (CSF) glutamate levels, which was strongly correlated with cognitive decline. Also, we demonstrated that memantine (MN), a glutamatergic NMDAR channel blocker, was capable of preventing the increase in CSF glutamate levels and cognitive decline. Here, we aimed to analyze whether the protective effects of MN involve intrinsic astrocytic properties, particularly related to glutamate uptake and astrocytic reactivity - indexed by the expression of S100B and glial fibrillary acidic protein (GFAP). Rats received intraperitoneal injections of MN or saline over 3 consecutive days before receiving intrahippocampal infusion of OKA or saline. Afterward, they were submitted to behavioral tasks and then, euthanatized for neurochemical analysis. Here, we showed that the neuroprotective effects of MN in response to OKA neurotoxicity involve astrocytic activation. MN decreased glutamate uptake in the hippocampus and increased the release of S100B protein in the CSF in response to OKA neurotoxicity, which indicates a possible neurons-astrocyte coupling protective mechanism. These findings shed light on astrocytes as potential targets for treating neurological disorders associated with decreased PP2A activity.

Violência entre pares: um estudo de caso numa escola pública de Esteio/RS / Violence among peers: a case study in a public school in Esteio/RS - Brazil / Violencia entre pares: un estudio de caso en una escuela pública de Esteio/RS

Este estudo investiga a "violência entre pares" numa escola de Esteio/RS. Participaram 161 alunos, sendo 102 da sétima e 59 da oitava série, 67 meninas e 94 meninos, com idades entre 12 e 20 anos (M ± DP = 14,09 ± 1,19). Foi utilizado o questionário "Violência entre Pares". Os resultados mostram que 56,9% dos alunos foram vítimas, 82,0%, observadores e 38,5%, agressores. Apenas 8,7% foram agredidos mais de três vezes. A agressão mais frequente foi a verbal (47,2%), seguida da física (21,1%) e de outras formas de agressão (13,7%). Discute-se o perfil dos agressores, que são predominantemente também vítimas, e 70,3% destas têm irmãos mais velhos. Há queda dos índices de vitimização nos meninos conforme aumenta a idade. A maioria dos alunos avaliou o ambiente escolar e a relação com os colegas como positiva, sem associação entre vitimização e piora dessas avaliações. A presença do bullying não foi significativa.

In this study we investigate the "peer violence" in a school Esteio / RS. 161 students participated, being 102 seventh graders and 59 eighth graders, 67 girls and 94 boys, aged between 12 and 20 years (M ± SD = 14.09 ± 1.19). We used the questionnaire "Peer Violence." The results show that 56.9% of the victims were students, 82.0%, observers, and 38.5%, offenders. Only 8.7% were assaulted more than three times. The aggression was verbal, most of the times (47.2%), followed by physical abuse (21.1%) and other forms of aggression (13.7%). We discuss the profile of the attackers, who are predominantly also victims. 70.3% of them have older siblings. There are drop rates of victimization in boys as they grow older. Most students rated the school environment and relationships with colleagues as positive. There is no association between victimization and worsening these evaluations. The presence of bullying was not significant.

Este estudio investiga la "violencia entre pares" en una escuela de Esteio/RS. Participaron 161 alumnos, siendo 102 del séptimo y 59 del octavo grado, 67 mujeres y 94 hombres, con edades entre 12 y 20 años (P ± DE = 14,09 ± 1,19). Se utilizó el cuestionario "Violencia entre Pares". Los resultados muestran que 56,9% de los alumnos fueron víctimas, 82,0%, observadores e 38,5%, agresores. Apenas 8,7% de los alumnos fueron agredidos más de tres veces. La agresión más frecuente fue verbal (47,2%), seguida de la física (21,1%) y de otras formas de agresión (13,7%). Se discute el perfil de los agresores que son, predominantemente, también víctimas, y 70,3% de estos tienen hermanos mayores. Hay disminución de los índices de victimización en los niños conforme aumenta la edad. La mayoría de los alumnos evaluó el ambiente escolar y la relación con los colegas como positiva, sin asociación entre victimización y empeoramiento de esas evaluaciones. La presencia de bullying no fue significativa.

Violência entre pares: um estudo de caso numa escola pública de Esteio/RS / Violence among peers: a case study in a public school in Esteio/RS - Brazil / Violencia entre pares: un estudio de caso en una escuela pública de Esteio/RS

Este estudo investiga a "violência entre pares" numa escola de Esteio/RS. Participaram 161 alunos, sendo 102 da sétima e 59 da oitava série, 67 meninas e 94 meninos, com idades entre 12 e 20 anos (M ± DP = 14,09 ± 1,19). Foi utilizado o questionário "Violência entre Pares". Os resultados mostram que 56,9% dos alunos foram vítimas, 82,0%, observadores e 38,5%, agressores. Apenas 8,7% foram agredidos mais de três vezes. A agressão mais frequente foi a verbal (47,2%), seguida da física (21,1%) e de outras formas de agressão (13,7%). Discute-se o perfil dos agressores, que são predominantemente também vítimas, e 70,3% destas têm irmãos mais velhos. Há queda dos índices de vitimização nos meninos conforme aumenta a idade. A maioria dos alunos avaliou o ambiente escolar e a relação com os colegas como positiva, sem associação entre vitimização e piora dessas avaliações. A presença do bullying não foi significativa.(AU)

In this study we investigate the "peer violence" in a school Esteio / RS. 161 students participated, being 102 seventh graders and 59 eighth graders, 67 girls and 94 boys, aged between 12 and 20 years (M ± SD = 14.09 ± 1.19). We used the questionnaire "Peer Violence." The results show that 56.9% of the victims were students, 82.0%, observers, and 38.5%, offenders. Only 8.7% were assaulted more than three times. The aggression was verbal, most of the times (47.2%), followed by physical abuse (21.1%) and other forms of aggression (13.7%). We discuss the profile of the attackers, who are predominantly also victims. 70.3% of them have older siblings. There are drop rates of victimization in boys as they grow older. Most students rated the school environment and relationships with colleagues as positive. There is no association between victimization and worsening these evaluations. The presence of bullying was not significant.(AU)

Este estudio investiga la "violencia entre pares" en una escuela de Esteio/RS. Participaron 161 alumnos, siendo 102 del séptimo y 59 del octavo grado, 67 mujeres y 94 hombres, con edades entre 12 y 20 años (P ± DE = 14,09 ± 1,19). Se utilizó el cuestionario "Violencia entre Pares". Los resultados muestran que 56,9% de los alumnos fueron víctimas, 82,0%, observadores e 38,5%, agresores. Apenas 8,7% de los alumnos fueron agredidos más de tres veces. La agresión más frecuente fue verbal (47,2%), seguida de la física (21,1%) y de otras formas de agresión (13,7%). Se discute el perfil de los agresores que son, predominantemente, también víctimas, y 70,3% de estos tienen hermanos mayores. Hay disminución de los índices de victimización en los niños conforme aumenta la edad. La mayoría de los alumnos evaluó el ambiente escolar y la relación con los colegas como positiva, sin asociación entre victimización y empeoramiento de esas evaluaciones. La presencia de bullying no fue significativa.(AU)