Novel role of NCoR1 in impairing spatial memory through the mediation of a novel interacting protein DEC2.

Long-term memory formation requires de novo RNA and protein synthesis. Using differential display PCR, we found that the NCoR1 cDNA fragment is differentially expressed between fast learners and slow learners, with fast learners showing a lower expression level than slow learners in the water maze learning task. Fast learners also show lower NCoR1 mRNA and protein expression levels. In addition, spatial training decreases both NCoR1 mRNA and protein expression, whereas NCoR1 conditional knockout (cKO) mice show enhanced spatial memory. In studying the molecular mechanism, we found that spatial training decreases the association between NCoR1 and DEC2. Both NCoR1 and DEC2 suppress the expression of BDNF, integrin α3 and SGK1 through C/EBPα binding to their DNA promoters, but overexpression of DEC2 in NCoR1 cKO mice rescues the decreased expression of these proteins compared with NCoR1 loxP mice overexpressing DEC2. Further, spatial training decreases DEC2 expression. Spatial training also enhances C/EBPα binding to Bdnf, Itga3 and Sgk1 promoters, an effect also observed in fast learners, and both NCoR1 and DEC2 control C/EBPα activity. Whereas knockdown of BDNF, integrin α3 or SGK1 expression impairs spatial learning and memory, it does not affect Y-maze performance, suggesting that BDNF, integrin α3 and SGK1 are involved in long-term memory formation, but not short-term memory formation. Moreover, NCoR1 expression is regulated by the JNK/c-Jun signaling pathway. Collectively, our findings identify DEC2 as a novel interacting protein of NCoR1 and elucidate the novel roles and mechanisms of NCoR1 and DEC2 in negative regulation of spatial memory formation.

Letrozole delays acquisition of water maze task in female BALB/c mice: Possible involvement of anxiety.

Letrozole, an aromatase inhibitor preventing estrogen synthesis from testosterone, is used as an adjuvant therapy in estrogen receptor-positive breast cancer patients. However, like other aromatase inhibitors, it induces many side effects, including impaired cognition. Despite its negative effect in humans, results from animal models are inconsistent and suggest that letrozole can either impair or improve cognition. Here, we studied the effects of chronic letrozole treatment on cognitive behavior of adult female BALB/c mice, a relevant animal model for breast cancer studies, to develop an appropriate animal model aimed at testing therapies to mitigate side effects of letrozole. In Morris water maze, letrozole 0.1 mg/kg impaired reference learning and memory. Interestingly, most of the letrozole 0.1 mg/kg-treated mice were able to learn the new platform position in reversal training and performed similar to control mice in a reversal probe test. Results of the reversal test suggest that letrozole did not completely disrupt spatial navigation, but rather delayed acquisition of spatial information. The delay might be related to increased anxiety as suggested by increased thigmotactic behavior during the reference memory training. The learning impairment was water maze-specific since we did not observe impairment in other spatial tasks such as in Y-maze or object location test. In contrast, the dose of 0.3 mg/kg did not have effect on water maze learning and facilitated locomotor habituation and recognition in novel object recognition test. The current study shows that letrozole dose-dependently modulates behavioral response and that its effects are task-dependent.

Acromegalic Rat Model Presented Cognitive Impairments and Tau Hyperphosphorylation in the Hippocampus.

INTRODUCTION: Acromegaly patients, in addition to the most prominent physical and endocrine changes, also exhibit a higher risk of cognitive dysfunction. However, the reasons and mechanisms underlying cognitive impairments in acromegaly patients remain unknown. METHODS: Acromegalic rats were induced by subcutaneous injection of tumor cells, with continuous monitoring of the body weight and hormones to confirm the occurrence of acromegaly. Behavioral assessments, including open field test, novel object recognition test, and Barnes maze test, were conducted to evaluate the animals' cognitive function. Western blotting, immunohistochemistry, and immunofluorescence techniques were employed to examine changes in the hippocampal tau protein, Aß, and associated signaling pathways. RESULTS: The tumor cells secreting growth hormone increased the secretion of growth hormone, resulting in changes in body size and endocrine functions, thus causing acromegaly. The acromegaly model showed deficiencies in working memory and spatial memory. Hyperphosphorylation of tau protein was observed in the hippocampus of the acromegaly model, but no Aß deposition was observed. The acromegaly model exhibits hippocampal growth hormone (GH) resistance, decreased expression of GH receptors, and subsequently reduced expression activity of the PI3K-Akt-GSK3ß signaling pathway, which is responsible for the hyperphosphorylation of tau protein. CONCLUSION: The prolonged elevation of GH and insulin-like growth factor 1 caused by acromegaly may lead to abnormalities in the SD rat's PI3K-Akt-GSK3ß signaling pathway, subsequently resulting in hyperphosphorylation of the hippocampal tau protein and cognitive impairment.

The influence of classical music on learning and memory in rats: a systematic review and meta-analysis.

During the learning process, music can activate important neural areas in the brain, promoting the retention of information and memory formation. However, studies testing music effects on memory had found different improvements, which could be due to the methodological differences across studies. Thus, the purpose of this article was to systematically review the literature and meta-analyze the effects of music on Rattus norvegicus' explicit memory (Maze tests) only in controlled investigations. The seven studies included led to a very homogeneous analysis (I2 = 0%), confirming the consistency of the significant standardized mean difference (SMD) between the memory of animals exposed and not exposed to music (SMD 0.60 (95% CI 0.38; 0.83, p < 0.001)). Exploratory analysis suggests music benefits on memory can be acquired when begun at any age, when tested with the three types of mazes evaluated, with exposure lasting from 8 to 83 days and when the age on test day was either under 30 days or over 30 days. To expand the actual understanding of music effects on memory, future studies should investigate different types of music and animal species, with different sex and health conditions, at different time points.

Intrathecal non-viral interleukin-10 gene therapy ameliorates neuropathic pain as measured by both classical static allodynia and a novel supra-spinally mediated pain assay, the Two-Arm Rodent Somatosensory (TARS) task.

Intrathecal delivery of interleukin-10 (IL-10) gene therapy has been reported to be effective in suppressing pain enhancement in a variety of rodent models. However, all publications that have tested this treatment have relied upon measures of static allodynia (von Frey test) and thermal hyperalgesia (Hargreaves test). As this plasmid DNA IL-10 (pDNA-IL10) therapeutic approach is now in human clinical trials for multiple pain indications, including intrathecal delivery for human neuropathic pain, it is important to consider the recent concerns raised in the pain field that such tests reflect spinal rather than supraspinal processing of, and responsivity to, noxious stimuli. Consequently, this raises the question of whether intrathecal pDNA-IL10 can reverse established neuropathic pain when assessed by a test requiring supraspinal, rather than solely spinal, mediation of the behavioral response. The present study utilizes the rat sciatic chronic constriction injury (CCI) model of neuropathic pain to compare the expression of static allodynia with that of cognitively controlled choice behavior in a two-arm maze, adapted from Hayashida et al. (2019). This modification, termed the Two-Arm Rodent Somatosensory (TARS) task, provides rats free choice to reach a desired goal box via a short "arm" of the maze with tactile probes as flooring versus a longer "arm" of the maze with a smooth surface. Here we demonstrate that static allodynia and avoidance of the nociceptive flooring in TARS develop in parallel over time, and that both behaviors also resolve in parallel following intrathecal pDNA-IL10 gene therapy. Details for the construction and use of this new maze design are also provided. Together, this study documents both: (a) the important finding that intrathecal IL-10 gene therapy does indeed resolve neuropathic pain as measured by a supraspinally-mediated behavioral task, and (b) a new, supraspinally-mediated task that allows behavioral assessments across weeks and allows the analysis of both development and resolution of neuropathic pain by therapeutic interventions. As such, the TARS operant behavior task is an improvement over other approaches such as the mechanical conflict-avoidance system which have difficulties demonstrating development and reversal of pain behavior in a within-subject design.

Neurobehavioral basis of Maier 3-table and other matching-to-place tasks.

The Maier 3-table task comprises three phases conducted each day. During the exploration phase, rats explore the entire apparatus. During the information phase, the rats are placed on one of the three tables where food is found. During the test phase, the animals are placed at the starting point on one of the two remaining tables and must enter the goal table where they previously ate. The acquisition of the Maier 3-table task was slowed down after lesions of the septum, fornix, hippocampus, medial prefrontal cortex, or posterior parietal cortex. Because of its time-consuming nature, the Maier 3-table task has more recently been superseded by appetitive matching-to-place in Y- or T-mazes or the circular water maze, because experimenters skip over the exploration phase. Nevertheless, like the Maier 3-table task, the acquisition of the Y- or T-maze matching-to-place task was retarded after lesions of the medial septum or medial prefrontal cortex, more particularly its prelimbic-infralimbic part. Like the previous task, the water-maze version is sensitive to lesions of the medial septum or retrosplenial cortex. Despite methodological differences between the three procedures, these results indicate common neurobiological bases of matching-to-place learning.

Evaluation of the Effect of Cariprazine on Memory and Cognition in Experimental Rodent Models.

The main symptoms of schizophrenia are categorized as positive, negative, and cognitive. Cognitive impairments do not generally respond to antipsychotics. Cariprazine is a novel antipsychotic conceived with the idea that high affinity for D3 receptors may elicit a favorable response in the management of cognitive deficits. We evaluated the pro-cognitive properties of 14-day long pre-treatment with cariprazine (0.25, 0.5, and 1 mg/kg b.w. intraperitoneally) in experimental rodent models with scopolamine-induced memory impairment employing novel object recognition test (NORT), T-maze, Y-maze, and passive avoidance tasks (step-through and step-down). Statistical analysis was performed with One Way ANOVA. In NORT cariprazine increased the recognition index. In T-maze and Y-maze cariprazine increased the working memory index as well as the percentage of spontaneous alternation. Cariprazine improved learning and memory in both short-term and long-term memory retention tests in step-down and step-through tasks. Cariprazine improves learning, recognition, and spatial memory in rats with scopolamine-induced memory impairment. Cariprazine's beneficial effect on cognition is likely due to its affinity for D3 receptors, as well as agonism at 5-HT1A receptors. Most probably, the cognitive-enhancing properties of cariprazine are the result of integrated modulation in the amygdala, hippocampus, and prefrontal cortex.

Intrahippocampal co-administration of nicotine and O-acetyl-L-carnitine prevents the H-89-induced spatial learning deficits in Morris water maze.

OBJECTIVES: H-89 (a protein kinase AII [PKA II] inhibitor) impairs the spatial memory in the Morris water maze task in rats. In the present study, we aimed to study the protective effects of nicotine and O-acetyl-L-carnitine against H-89-induced spatial memory deficits. METHODS: Spatial memory impairment was induced by the bilateral intrahippocampal administration of 10 µM H-89 (dissolved in dimethyl sulfoxide, DMSO) to rats. The rats then received bilateral administrations of either nicotine (1 µg/µL, dissolved in saline) or O-acetyl-L-carnitine (100 µM/side, dissolved in deionized water) alone and in combination. Control groups received either saline, deionized water, or DMSO. RESULTS: The H-89-treated animals showed significant increases in the time and distance travelled to find hidden platforms, and there was also a significant decrease in the time spent in the target quadrant compared to DMSO-treated animals. Nicotine and O-acetyl-L-carnitine had no significant effects on H-89-induced spatial learning impairments alone, but the bilateral intrahippocampal co-administration of nicotine and O-acetyl-L-carnitine prevented H-89-induced spatial learning deficits and increased the time spent in the target quadrant in comparison with H-89-treated animals. CONCLUSIONS: Our results indicated the potential synergistic effects of nicotine and O-acetyl-L-carnitine in preventing protein kinase AII inhibitor (H-89)-induced spatial learning impairments.

Rapid spatial learning in cooperative and non-cooperative cichlids.

The number, duration and depth of social relationships that an individual maintains can impact social cognition, but the connection between sociality and other aspects of cognition has hardly been explored. To date, the link between social living and intelligence has been mainly supported by studies on primates, and far fewer tests connecting sociality to cognitive abilities have used other taxa. Here, we present the first comparative study in fishes that examines whether complex social living is associated with better performance on a cognitively demanding spatial task. Using three cooperative, group-living cichlid fish species and three of their non-cooperative, more solitary close relatives, we studied maze learning and employed a new statistical extension for the 'lme4' and 'glmmTMB' packages in R that allows phylogeny to be included as a random effect term. Across trials, the three cooperative and the three non-cooperative species completed the maze faster, made fewer mistakes, and improved their inhibitory control. Although fish improved their performance, we did not detect any differences in the extent of improvement between cooperative and non-cooperative species. Both the cooperative species and the non-cooperative species took similar amounts of time to complete the maze, had comparable numbers of mistakes, and exhibited similar inhibitory control while in the maze. Our results suggest that living and breeding in complex social groups does not necessarily imply enhancement of other forms of cognition nor, more specifically, an enhanced spatial learning capacity.

The effects of aging and dopaminergic inhibition on large scale maze learning in rhesus monkeys.

Studies have shown that both aging and dopaminergic dysfunction affected spatial learning and memory. Systematic dopaminergic inhibition, by dopamine receptor (DR) antagonist treatment, impaired spatial delayed-response (SDR) performance, which mostly requires self/body centered egocentric reference frame, in rhesus monkeys. However, the influence of DR blocking on large scale maze learning, which mainly involves world centered allocentric reference frame, remains unclear. Moreover, the effects of aging on the process also remain unknown. Present study investigated the issues, using large scale mazes composed of 8 maze units. Maze No. 1 was used for adaptation and training. Mazes No. 2-4 were used to investigate influence of aging, by comparing learning performance between young and aged rhesus monkeys. Mazes No. 5-8 were used to investigate the effects of DR antagonist treatment, SKF-83566 (0.02, 0.2 mg/kg) and haloperidol (0.001, 0.01 mg/kg). The result showed similar learning performance between young and aged monkeys in mazes No. 2-4. In mazes No. 5-8, we also found similar learning performance after acute DR antagonist injection, compared with pre-treatment baseline performance in mazes No. 2-4, in both young and aged groups. The result showed similar maze learning performance between young and aged monkeys in mazes (No. 2-4), suggesting no significant influence of aging on allocentric spatial learning. We also found similar maze performance in both groups, after dopamine receptor antagonist treatment in mazes (No. 5-8) compared with pre-treatment baseline performance in mazes (No. 2-4), suggesting no significant influence of dopaminergic inhibition on allocentric spatial learning. Together, the present study potentially suggested insensitivity of allocentric spatial learning to cognitive aging and acute systematic dopaminergic inhibition.

Effect of electroacupuncture on the learning and memory abilities in type 2 diabetic model rats with cognitive impairment / 针灸推拿医学（英文版）

Objective: To observe the effects of electroacupuncture (EA) on the protein and gene expressions of Bax, Caspase-3 and Bcl-2 in cerebral cortex of type 2 diabetic rats with cognitive impairment (CI), and to explore the mechanism of EA in improving the learning and memory abilities. Methods: A total of 100 Sprague-Dawley (SD) rats were divided into a normal group (n=10) and a model group (n=90) by random number table method. Rats in the model group were intraperitoneally injected with a small dose of streptozotocin (STZ) to establish the type 2 diabetic models, after being fed with high-fat and high-sugar diet for 1 month. Twenty CI rats were selected from the 50 successful model rats by the Morris water maze (MWM) test and randomly divided into a model group and an EA group according to the blood glucose level and MWM data (n=10). Rats in the EA group received acupuncture at Zusanli (ST 36), Neiting (ST 44) and Yishu (Extra), of which Zusanli (ST 36) and Neiting (ST 44) were stimulated by EA apparatus, 20 min/time, once a day for 6 d a week and 4 consecutive weeks. The rats in the model and the normal groups were fixed without treatment. After 4-week treatment, the random blood glucose level of the rats was measured; the learning and memory abilities of rats were measured by MWM; terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was used to detect apoptotic cells; Western blot (WB) and real-time quantitative polymerase chain reaction (RT-qPCR) were used to detect the protein and gene expressions of Bax, Caspase-3 and Bcl-2 in cerebral cortex. Results: After modeling, the random blood glucose level and the escape latency tested by MWM were significantly increased, and the number of crossing the platform tested by the MWM was decreased in the EA and model groups, and were significantly different from those in the normal group (P<0.05 or P<0.01), while the differences between the model group and the EA group were not statistically significant (all P>0.05). After 4-week treatment, the random glucose level and the escape latency tested by MWM were significantly increased (both P<0.05), and the number of crossing the original platform tested by the MWM was significantly reduced (P<0.01), the protein and gene expressions of Bax and Caspase-3 were significantly increased (all P<0.001), the protein and gene expressions of Bcl-2 were significantly reduced (both P<0.001), and the number of neuron apoptosis was significantly increased (P<0.001) in the model group than in the normal group; the random blood glucose level was significantly reduced (P<0.05), the escape latency tested by MWM was significantly shortened (P<0.05), and the number of crossing the original platform tested by MWM was significantly increased (P<0.05), the protein and gene expressions of Bax and Caspase-3 were significantly reduced (all P<0.001), the protein and gene expressions of Bcl-2 were significantly increased (both P<0.001), and the number of neuron apoptosis was significantly reduced (P<0.001) in the EA group than in the model group. Conclusion: EA can improve the learning and memory damages induced by type 2 diabetic model rats with CI; the action mechanism may be achieved via anti-apoptosis.

Behavioral and electrophysiological aspects of cognition in neonate rats lactated by morphine addicted mothers.

OBJECTIVES: In addition to genetic factors, environmental phenomena during postnatal age highly affect development and, in turn, function of the brain. The present work evaluates if morphine consumption during lactation period influences the spatial performances and synaptic plasticity in rats at neonatal period of age. MATERIALS AND METHODS: Three groups of mothers were subcutaneously administered by 5 (M5), 10 (M10) or 20 (M20) mg/kg morphine every 12 hours during the lactation period. At 45 days old, their offspring were introduced to Morris water maze for assessment of spatial learning and memory. Basic field excitatory post-synaptic potentials (fEPSPs) were recorded in the CA1 area of hippocampus and, then, long term potentiation (LTP) was induced by tetanic stimulation. RESULTS: We found that the M10 and M20 rats spent more time and traveled longer distance to find the hidden platform of maze when compared to the control animals (P<0.05 for all comparisons). Similarly, these two morphine-exposed groups were inferior in the memory consolidation compared to their control counterparts. Comparing control and M20 rats revealed that morphine exposure decreases the mean amplitude and slope 10-90% of fEPSPs about 30 percent (P<0.001 for both comparisons) and inhibits the LTP induction in the CA1 area circuits. CONCLUSION: The present study provides behavioral and electrophysiological proofs for negative effect of morphine on the hippocampal-related function in the neonatally morphine-exposed rats.

Returning to home cage serves as an effective reward for maze learning in rats.

This study examined the effectiveness in rats of 'returning to home cage' as a reward for learning a Lashley III maze. Rats could return to their home cage directly (Direct HC group) or they could be removed manually by an experimenter from the maze's goal box (Indirect HC group). In the third group, hungry rats received a food reward in the goal box (Food group). The Direct HC group reliably learned the maze and its performance was very similar to that of the Food group. In contrast, performance by the Indirect HC group was significantly poorer than the Direct HC group, as well as the Food group, possibly due to the negative impact of handling during removal from the goal box. These results suggest that a 'home cage reward' is as effective a procedure for rats in maze learning as previously reported in mice (Blizard et al., 2003, 2006).

Effects of piperonyl butoxide on exploratory behaviour in female mice.

Previous studies reported that piperonyl butoxide (PBO) induces adverse effects on exploratory behaviour in male mice. However, no consistent effects of PBO treatment were observed in female mice. This study aimed to evaluate PBO's neurobehavioral effects in female mice. Female mice were exposed to PBO through diet to provide levels of 0 (control), 0.025%, 0.1%, and 0.4% from 5 to 12 weeks of age, and selected behavioural parameters were measured. The average female body weight showed no significant effect from PBO treatment through the experimental periods. Regarding multiple-T water maze performance at 10 weeks of age, no significant effect caused by PBO treatment was observed. Exploratory behaviour examination of 8-week-old female mice indicated that the average speed declined in a significant dose-related manner, and the longitudinal pattern indicated a significant difference between the control and high-dose groups. For exploratory behaviour examination at 11 weeks of age, the total exploration distance shortened in a significant dose-related manner, and the average speed declined similarly. These longitudinal patterns showed significant differences between the control and high-dose groups. The PBO dose levels in this study produced several adverse effects on exploratory behaviour in female mice.

Comparison of PC and iPad administrations of the Cogstate Brief Battery in the Mayo Clinic Study of Aging: Assessing cross-modality equivalence of computerized neuropsychological tests.

Objective: Computerized neuropsychological assessments are increasingly used in clinical practice, population studies of cognitive aging and clinical trial enrichment. Subtle, but significant, performance differences have been demonstrated across different modes of test administration and require further investigation. Method: Participants included cognitively unimpaired adults aged 50 and older from the Mayo Clinic Study of Aging who completed the Cogstate Brief Battery and Cogstate's Groton Maze Learning Test (GMLT) on an iPad or a personal computer (PC) in the clinic. Mode of administration differences and test-retest reliability coefficients were examined across 3 cohorts: a demographically matched test-retest cohort completing PC and iPad administrations the same day (N = 168); a test naïve cohort comparing baseline PC (n = 1820) and iPad (n =605) performance; and a demographically matched longitudinal cohort completing 3 Cogstate visits over 15 months on either the PC (n =63) or iPad (n =63). Results: Results showed a small but statistically significant and consistent finding for faster performance on PC relative to iPad for several Cogstate Brief Battery measures. Measures of accuracy generally did not differ or differences were very small. The GMLT showed faster performance and higher total errors on iPad. Most Cogstate variables showed no difference in the rate of change across PC and iPad administrations. Conclusions: There are small, but significant, differences in performance when giving the same cognitive tests on a PC or an iPad. Future studies are needed to better understand if these small differences impact the clinical interpretation of results and research outcomes.

Spatial Learning Responses to Lipopolysaccharide in Adult and Aged Rats.

Sickness behaviors, adaptive responses to infections, include lethargy, depression, reduced eating and grooming, and concentration problems resulting from interactions between the immune and neuroendocrine systems. Detecting these responses is especially critical in the elderly, as the infections that cause them can lead to cognitive impairment. While deficits in spatial learning, a hippocampal-dependent form of learning, are part of the sickness response, directional heading errors (DHEs; an indicator of spatial-learning deficits) and their time trajectories need further examination. Therefore, we simultaneously investigated the time trajectory of age-dependent sickness responses and spatial learning over 5 days in adult (5-6 months) and aged (22 months) male Brown-Norway rats injected with 250 µg/kg lipopolysaccharide (LPS; experimental group) or 0.9% sodium chloride (control group). LPS administration resulted in pronounced, age-dependent weight loss and decreased food intake that persisted in the aged group. Animals were tested for 5 days (trial) in the Morris water maze. After 7 days of rest, animals were retested for 2 days (retention). Adult and aged LPS-treated animals displayed greater differences in mean DHE than the control groups, indicating that they exhibited more DHE over the trial days. Experimental groups did not show consistent DHE improvement until Day 4 (adult) or 5 (aged). LPS had no effect on probe or retention trials. We conclude that LPS activation of the immune system results in a selective, age-dependent impairment in spatial learning, decreased food intake, and weight loss. All of these results are prolonged in aged animals.

Intervention effect of CD147 on learning and memory ability in rat model of Alzheimer's disease / 天津医药

Objective To investigate the intervention effect of CD147 on learning and memory ability in rat model of Alzheimer's disease. Methods A total of 60 healthy Sprague-Dawley rats were randomly divided into sham operation group, model group and CD147 group, 20 rats in each group. All of the rats were anesthetized with intraperitoneal injection of 10％chloral hydrate (0.3 g/kg). The rats in the model group and the CD147 group were injected with Aβ1-40 (10μg) in the bilateral hippocampal CA1 regions, while the rats in the sham operation group were injected with the same amount of saline at the same sites. After 48 h, the rats in CD147 group were injected with CD147 cDNA in the bilateral ventricles, while the rats in model group and sham operation group were injected the same amount of saline at the same sites. Morris water maze test was used to detect the ability of learning and memory of rats. The expressions ofβamyloid protein (Aβ) andγ-secretase were detected by Western blot assay. Results The escape latency was significantly longer in model group than that of sham operation group, while which was significantly lower in CD147 group than that of model group (P<0.05). The number of times across the platform and the time of staying on platform were significantly lower in model group than those of sham operation group, while which was significantly higher in the CD147 group than that of model group (P<0.05). The expressions of Aβandγ-secretase were increased significantly in model group compared to those of sham operation group, while which were significantly decreased in CD147 group compared with those of model group (P<0.05). Conclusion Exogenous CD147 can significantly improve the learning and memory ability of AD rats, and its specific mechanism may be related to regulating the activity ofγ-secretase and down regulating the expression of Aβ.

Motor learning in children and adolescents institutionalized in shelters / Aprendizagem motora em crianças e adolescentes institucionalizados em abrigo

Abstract Introduction: Children and adolescents living in shelters may present with impaired motor development, cognitive function, as well as speech and understanding; psychological alterations; and hyperactivity. All of these factors may be detrimental to motor learning. Objective: To investigate motor learning in children and adolescents living in shelters, and to compare it with that of individuals living in a family context. Methods: We assessed 36 individuals who were divided into groups: an experimental group, composed of institutionalized children and adolescents (EG, n=18), and a control group (CG, n = 18) that was matched by age and sex. Motor learning was assessed using a maze test in three stages: acquisition, retention and transfer. The data were analyzed using the Shapiro Wilk, Wilcoxon, Mann Whitney, Kruskal Wallis tests and Dunn's post-test (p < 5%). Results: The EG had a longer task performance time than the CG. There was a significant reduction in task performance time between the first (EG = 11.05 [8.50-14.85]s; CG:7.65 [5.95-10.23]s) and the last task performance block (EG:8.02 [6.86-10.23]s; GC: 5.50 [4.50-6.82]s) in both groups. When comparing the variables of the last acquisition (GE:8.02[6.86-10.23]s; GC: 5.50[4.50-6.82]s), retention (GE:8.20[7.09-9.89]s;GC:5.35[4.50-6.22]s) and transfer blocks (GE:8.30[6.28-11.43]s; GC:5.30[4.90-6.82]s) in each group, we found no changes in task performance time between test batteries. Conclusion: Individuals living in shelters showed a motor learning deficit, as evidenced by longer task performance time when compared to their controls. Nevertheless, both groups performed the task in a similar manner.

Resumo Introdução: Crianças e adolescentes institucionalizados podem apresentar comprometimentos do desenvolvimento motor; das funções cognitiva, da fala, da compreensão; alterações psicológicas e hiperatividade, que podem ser prejudiciais para a aprendizagem motora. Objetivo: Analisar a aprendizagem motora de crianças e adolescentes institucionalizados em abrigo e comparar com indivíduos em contexto familiar. Métodos: Foram avaliados 36 indivíduos divididos em 2 grupos: grupo experimental, composto por crianças e adolescentes institucionalizados (GE, n=18) e grupo controle (GC, n =18), pareados por sexo e idade. Para avaliação da aprendizagem motora foi utilizada a tarefa de labirinto realizada em três fases: aquisição, retenção e transferência. Para análise dos dados foram utilizados os testes de Shapiro Wilk, Wilcoxon, Mann Whitney, Kruskal Wallis e pós-teste de Dunn (p < 5%). Resultados: O GE obteve maior tempo para execução da tarefa comparado com o GC. Houve diminuição significativa do tempo de execução da tarefa, do primeiro bloco (GE= 11,05 [8,50-14,85]s; GC:7,65 [5,95-10,23]s) para o último bloco da aquisição (GE:8,02 [6,86-10,23]s; GC: 5,50 [4,50-6,82]s) em ambos os grupos. Ao comparar as variáveis entre o último bloco da aquisição (GE:8,02[6,86-10,23]s; GC: 5,50[4,50-6,82]s), retenção (GE:8,20[7,09-9,89]s; GC:5,35[4,50-6,22]s) e transferência (GE:8,30[6,28-11,43]s; GC:5,30[4,90-6,82]s) em cada grupo, foi encontrada a manutenção do tempo para execução da tarefa durante as fases. Conclusão: Os indivíduos institucionalizados em abrigo apresentaram um déficit na aprendizagem motora, verificada pelo maior tempo de execução da tarefa comparado aos indivíduos não institucionalizados, porém ambos evoluem de maneira semelhante durante a realização da tarefa.

Effects of low-dose lipopolysaccharide and age on spatial learning in different Morris water maze protocols.

OBJECTIVES: Animals administered lipopolysaccharide exhibit dose-related sickness behaviors (decreased food intake, weight loss, and cognitive changes). While research has demonstrated that spatial learning is impaired following a lipopolysaccharide immune challenge, the results differ depending on the methodology used to evaluate spatial learning. Additionally, few studies have evaluated the effects of low-dose lipopolysaccharide on spatial learning. Therefore, we assessed spatial learning, food intake, and weight changes in adult and aged rats after a low-dose lipopolysaccharide immune challenge in the Morris water maze using two water temperatures. METHODS: Adult (5-6 months) and aged (22 months) male Brown-Norway rats were administered either 50 or 100 µg/kg lipopolysaccharide or saline, and then tested in the Morris water maze for 5 days, rested for 7 days, and later underwent 2 days of retention tests. Probe trials were conducted at the end of initial and retention testing. RESULTS: Low-dose lipopolysaccharide administration did not result in food intake or weight changes. While the aged experimental group took longest to improve directional heading error in both cold and warm water, heading error was greater in cold water. Behavioral testing revealed an apparent age and water temperature effect on swim time. Retention and probe trial results showed that aged experimental animals had the worst performance in cold water. CONCLUSION: We conclude that while low-dose lipopolysaccharide did not result in typical sickness behaviors (decreased food intake or weight), spatial learning and memory were impaired in the aged experimental group. These results have important implications for the care of elderly individuals experiencing mild to moderate infections.

Effects of 2,2',4,4'-tetrabromodiphenyl ether on neurobehavior and memory change and bcl-2, c-fos, grin1b and lingo1b gene expression in male zebrafish (Danio rerio).

Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants in various environmental matrices and organisms and pose a threat to neural systems of organisms. However, though quite a few studies have explored the effect of PBDEs on neural behaviors such as learning and memory abilities in animals, their mechanisms are less known. We used the zebrafish model to evaluate neurotoxicity of PBDEs and observe changes in behavior and related gene expression. In behavioral testing, 50 zebrafish were divided into five groups treated with different concentrations of BDE-47. T-maze exploration was used for learning and memory testing, which was recorded by camera every 7days. After 21days, all fish were killed, and the gene expression of c-fos, bcl-2, lingo1b and grin1b in brain tissue was analyzed by RT-qPCR. The behavioral changes (latency to leave the start zone, reach the reward zone, and stay in the reward zone; accuracy in choosing the right maze arm, accumulation of freezing bouts, etc.) were related to BDE-47 concentration and had a time-effect relation with increasing exposure days, especially with 500µg/L BDE-47. BDE-47 elevated brain bcl-2, grin1b and lingo1b expression. The expression of c-fos showed an increase with 50 and 100µg/L BDE-47 exposure. The PBDE BDE-47 had a negative impact on the neurobehaviors of zebrafish and affected the expression of c-fos, bcl-2, lingo1b and grin1b in zebrafish brain tissue.