Liane da Silva de Vargas

Hippocampal noradrenergic activation is necessary for object recognition memory consolidation and can promote BDNF increase and memory persistence.

Previously we showed that activation of the Nucleus of the Solitary Tract (NTS)-Nucleus Paragigantocellularis (PGi)-Locus coeruleus (LC) pathway, which theoretically culminates with norepinephrine (NE) release in dorsal hippocampus (CA1 region) and basolateral amygdala (BLA) is necessary for the consolidation of object recognition (OR) memory. Here we show that, while the microinjection of the beta-noradrenergic receptor blocker timolol into CA1 impairs OR memory consolidation, the microinjection of norepinephrine (NE) promotes the persistence of this type of memory. Further, we show that OR consolidation is attended by an increase of norepinephrine (NE) levels and of the expression of brain derived neurotrophic factor (BDNF) in hippocampus, which are impaired by inactivation of the NTS-PGi-LC pathway by the infusion of muscimol into the NTS.

The use of Facebook as a tool to increase the interest of undergraduate students in physiology in an interdisciplinary way

the process of teaching and learning at the undergraduate level is challenged by an increasing amount of content ([1][1]). Now its not enough to convey knowledge; its also necessary to seek alternative ways to motivate and capture the interest of students both during class and outside of class.

One-single physical exercise session after object recognition learning promotes memory persistence through hippocampal noradrenergic mechanisms

&NA; Previously we showed the involvement of the hippocampal noradrenergic system in the consolidation and persistence of object recognition (OR) memory. Here we show that one‐single physical exercise session performed immediately after learning promotes OR memory persistence and increases norepinephrine levels in the hippocampus. Additionally, effects of exercise on memory are avoided by an intra‐hippocampal beta‐adrenergic antagonist infusion. Taken together, these results suggest that exercise effects on memory can be related to noradrenergic mechanisms and acute physical exercise can be a non‐pharmacological intervention to assist memory consolidation and persistence, with few or no side effects. HighlightsAcute physical exercise promotes recognition memory persistence.Physical exercise effects on memory are similar to norepinephrine effects.Acute physical exercise increases norepinephrine levels in hippocampus.

Increased Interest in Physiology and Science among Adolescents after Presentations and Activities Administered by Undergraduate Physiology Students.

beginning in the 1980s, the Brazilian government introduced strategies to promote universal access to primary education, which coincided with an increase in the number of 6-yr-old children entering the educational system and the expansion of the public high school system ([10][1]). More recently,

The intrahippocampal infusion of crotamine from Crotalus durissus terrificus venom enhances memory persistence in rats.

Previous research has shown that crotamine, a toxin isolated from the venom of Crotalus durissus terrificus, induces the release of acetylcholine and dopamine in the central nervous system of rats. Particularly, these neurotransmitters are important modulators of memory processes. Therefore, in this study we investigated the effects of crotamine infusion on persistence of memory in rats. We verified that the intrahippocampal infusion of crotamine (1 μg/μl; 1 μl/side) improved the persistence of object recognition and aversive memory. By other side, the intrahippocampal infusion of the toxin did not alter locomotor and exploratory activities, anxiety or pain threshold. These results demonstrate a future prospect of using crotamine as potential pharmacological tool to treat diseases involving memory impairment, although it is still necessary more researches to better elucidate the crotamine effects on hippocampus and memory.

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

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.

Intrahippocampal Infusion of Crotamine Isolated from Crotalus durissus terrificus Alters Plasma and Brain Biochemical Parameters

Crotamine is one of the main constituents of the venom of the South American rattlesnake Crotalus durissus terrificus. Here we sought to investigate the inflammatory and toxicological effects induced by the intrahippocampal administration of crotamine isolated from Crotalus whole venom. Adult rats received an intrahippocampal infusion of crotamine or vehicle and were euthanized 24 h or 21 days after infusion. Plasma and brain tissue were collected for biochemical analysis. Complete blood count, creatinine, urea, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), creatine-kinase (CK), creatine kinase-muscle B (CK-MB) and oxidative parameters (assessed by DNA damage and micronucleus frequency in leukocytes, lipid peroxidation and protein carbonyls in plasma and brain) were quantified. Unpaired and paired t-tests were used for comparisons between saline and crotamine groups, and within groups (24 h vs. 21 days), respectively. After 24 h crotamine infusion promoted an increase of urea, GOT, GPT, CK, and platelets values (p ≤ 0.01), while red blood cells, hematocrit and leukocytes values decreased (p ≤ 0.01). Additionally, 21 days after infusion crotamine group showed increased creatinine, leukocytes, TBARS (plasma and brain), carbonyl (plasma and brain) and micronucleus compared to the saline-group (p ≤ 0.01). Our findings show that crotamine infusion alter hematological parameters and cardiac markers, as well as oxidative parameters, not only in the brain, but also in the blood, indicating a systemic pro-inflammatory and toxicological activity. A further scientific attempt in terms of preserving the beneficial activity over toxicity is required.

NOVELTY EXPOSURE HINDERS AVERSIVE MEMORY GENERALIZATION AND DEPENDS ON HIPPOCAMPAL PROTEIN SYNTHESIS

HighlightsRats express aversive memory generalization when tested in contexts similar to the one of learning.The exposure to a novel environment hinders aversive memory generalization.Intrahippocampal infusion of anisomycin blocked the novelty effect.Intrahippocampal infusion of rapamycin blocked the novelty effect.Novelty exposure effects depending on hippocampal protein synthesis. Abstract Fear generalization is defined as the transferring of fear experienced during a traumatic event to safe conditions resembling or not the traumatic event. It has been related to several psychological disorders. Here we set out to determine whether novelty exposure can be effective to avoid fear generalization. We evaluated the effect of a novelty exposure on fear memory generalization using an aversive memory task, the inhibitory avoidance (IA). Male Wistar rats were trained in IA (day 1) and 24 h after (day 2) they were exposed to a new context similar to the original (modified IA ‐ MIA), with some rats being exposed to a novelty just before the exposure to the MIA, while others were not (controls). On day 3, retention tests for IA and MIA contexts were performed. The control rats generalized the memory, expressing aversive behavioral in both contexts whereas rats exposed to novelty only expressed aversion on IA. Furthermore, both anisomycin, an inhibitor of ribosomal protein synthesis, and rapamycin, an inhibitor of mTOR‐mediated protein synthesis, injected in the CA1 region of dorsal hippocampus blocked the novelty effect, promoting memory generalization. We conclude that novelty exposure hinders aversive memory generalization depending on hippocampal protein synthesis.

Formação continuada em Neuroeducação: percepção de professores sobre a neurociência e sua importância para a educação

A neurociencia contribui para a compressao de como o cerebro aprende, qualificando a escolha de estrategias de ensino e aprendizagem. Aqui, objetivamos relatar a percepcao e o conhecimento de professores acerca da neurociencia antes e apos um curso de formacao continuada. O curso foi realizado em duas etapas, contando com adesao de 13 docentes. Segundo os mesmos, a neurociencia nao havia sido abordada na formacao inicial de 69,2% deles; 77,7% relatou ter algum conhecimento acerca do tema adquirido por outros meios que nao a educacao formal. Ao final, todos conceituaram neurociencia adequadamente, afirmando que esta tem uma importante relacao com a educacao.

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.