Increase in Hippocampal Theta Oscillations during Spatial Decision Making

The processing of spatial and mnemonic information is believed to depend on hippocampal theta oscillations (5–12 Hz). However, in rats both the power and the frequency of the theta rhythm are modulated by locomotor activity, which is a major confounding factor when estimating its cognitive correlates. Previous studies have suggested that hippocampal theta oscillations support decision-making processes. In this study, we investigated to what extent spatial decision making modulates hippocampal theta oscillations when controlling for variations in locomotion speed. We recorded local field potentials from the CA1 region of rats while animals had to choose one arm to enter for reward (goal) in a four-arm radial maze. We observed prominent theta oscillations during the decision-making period of the task, which occurred in the center of the maze before animals deliberately ran through an arm toward goal location. In speed-controlled analyses, theta power and frequency were higher during the decision period when compared to either an intertrial delay period (also at the maze center), or to the period of running toward goal location. In addition, theta activity was higher during decision periods preceding correct choices than during decision periods preceding incorrect choices. Altogether, our data support a cognitive function for the hippocampal theta rhythm in spatial decision making

Avaliação de efeitos toxicológicos e comportamentais de ginseng panax em ratos

Panax ginseng CA Meyer (Araliaceae) is a herbaceous plant widely used in China, South Korea, Japan and other Asian countries for the treatment of various diseases micro circulatory, cerebrovascular, among others, representing one of the drugs used by older man. It has over 30 biologically active ginsenosides with different pharmacological and behavioral effects and inhibitory effect on the NMDA receptor. The amino acid glycine is a co-agonist of the NMDA receptor, activating this receptor. At the cellular level, ketamine is widely known to be NMDA receptor antagonist. The aim of this study was to evaluate the general activity in the open field, and anxiety in elevated plus maze, mice treated with P. ginseng compared with the action of ketamine and glycine, to better understand the action of this herbal medicine at the NMDA receptor. We used 66 adult male rats were divided into six groups: a positive control, treated for 30 days with water by gavage, who received glycine (500mg/kg; po) on days 7, 14, 21 and 28 of treatment, one hour before of behavioral assessment, a negative control was treated for 30 days with water by gavage received ketamine (5mg/kg, ip) on days 7, 14, 21 and 28 of treatment, one hour prior to behavioral evaluation, three experimental groups, receiving 100, 200 or 300 mg / kg P. ginseng by gavage for 30 days and one group treated solely with white water, and is also administered 1 ml of water by gavage one hour prior to behavioral evaluation. Animal behavior in these three groups was also examined on days 7, 14, 21 and 28 of treatment. On day 30 of treatment, the animals were anesthetized with thiopental (70mg/kg) for blood collection and after euthanasia, withdrawal of various organs. There were no changes in weight and body weight gain and weight reasons in organ / body weight. However the consumption of water and food values showed a significant increase. Serum levels of AST was increased in a dose-dependently in the animals treated with doses of P. ginseng, glycine and ketamine as compared to the blank group. Unlike creatinine levels proved to be decreased in all treated groups when compared with white. However, the level of urea in these groups was reduced and no changes were observed in the ALT parameter. Histopathological examination revealed no changes in cell morphology in different tissues. There were no behavioral changes in the elevated plus maze and few changes were observed in the open field, animals treated with P. ginseng, glycine and ketamine when compared to white. These data suggest that the doses of P. ginseng employed were unable to induce general toxicity in rats treated for 30 days and also shows that the general behavior of mice treated with P. ginseng was slightly different from that observed in animals treated with ketamine and glycine. Finally, the study on the elevated plus maze showed that the extract of P. ginseng showed no anxiolytic or anxiogenic action

Acurácia do teste de labirinto no rastreamento de déficits cognitivos em idosos

This study intended to evaluate the maze test accuracy in cognitive deficit screening in elderly with or without neuropsychological pathology. The sample included 40 healthy young (18-25 years old; mean- 21 ± 1.6), 40 healthy old (60-77 years old; mean- 67 ± 5.1) and 18 patients with probable diagnosis of Alzheimer s disease initial stage (52-90 years old; mean- 78 ± 9.2). Data analysis was made using Anova with Tukey s post hoc, multiple linear regression analysis and ROC curve analysis. According to Tukey s test Alzheimer patients spent more time (46843 ± 37926 ms) to execute the test than healthy young (5482 ± 2873 ms; p= 0.0001) and elderly (17978 ± 13700; p= 0.0001); healthy young executed test n lower time (p= 0.035). According to the regression analysis of age, education level and cognitive performance of the three groups, the cognitive performance was the predictor of the execution time. When analyzing young and elderly only age was the predictor and the cognitive performance was the only factor to influence the test of old aged healthy and patients. The ROC curve analysis indicated 72% accuracy for young and elderly and 36% for healthy and elderly patients. The maze execution time represented a better balance between sensibility (75%) and the specificity (61%) was near 13575 ms, indicating that those subjects that execute the maze in a time higher to this value may show cognitive deficit related to the executive function. According to the results it is suggested that the maze test used in this study shows a good accuracy in the cognitive deficit tracking and may discriminate age changes

Trajetos no labirinto: história de vida dos portadores de doenças oncológicas em uso de transfusões sanguíneas na cidade de Natal/RN

The studies paths in the maze: life story of individuals with oncological diseases into use of blood transfusion in Natal has the hemotherapy as a primordial procedure to review the relationship between users of oncological health and the due ramifications. The hemotherapy looks for supply the organic needs through blood transfusion, which acquires vital function to the ones that have cancer, because it might reestablish the functionality of the organism throughout the raising of blood components. The impact over the transfusion affects emotionally and physically the users life. Aiming to reflect on these impacts, this study tried, through narratives of lives, rescue their experience since their knowledge of the disease until the time of blood transfusion using. It s about an exploratory-descriptive study, where the qualitative approach uses the theoretical-methodological reference of the oral life history to analyze a colony consisting of five users of health diagnosed with cancer, with achievement of at least three blood transfusions, the clinic Núcleo de Hematologia e Hemoterapia - UFRN, in Natal-RN. The network, in turn, was composed by employees of both sexes, regardless of age, who voluntarily agreed to participate in the study. The data collection, with approval of the Ethics Committee in Research, Liga Norte Riograndense Contra o Cancer, on the number 001/001/2012, occurred through semi-structured interviews, recorded individually in the home context that was previously chosen by employees. The methodological procedure occurred with the transcription of the interviews and their transcreations, and analysis of reports by thematic content analysis. At the reading orientation and interpretation of the employees stories, were discussed three categories of analysis: the impact on psychological REVIEW; impact on socialization and group membership, the environment and the impact of blood transfusion on treatment. Based on the narrative of the life histories of employees, we conclude that the experiences and feelings, hope and sorrow, pain and faith, even when facing a disease like cancer, bring lots of teaching and learning to health professional that deposits humanization health and reinstate hemotherapy forms of clinical critical

O imaginário da mediunidade no processo de escritura em Fernando Pessoa

The answer to creating a fictional world? Repulsion or form of reaction to an outside world? Mental illness, whose brand can be symbolic simulation or depersonalization? Hard to take a stand when the deed is a poet Fernando Pessoa as what is at stake. Notes Schlafman Léo (1998) who, at the age of 20 years, Fernando Pessoa wrote in English, in his diary, "One of my mental complications is the fear of madness, which in itself already is crazy." What rid of madness, notes Robert Bréchon (1986), was the taste of the game and was playing it for your writing. Even though it has rid the madness, the poet does not quit seeking explanations - or provide it - for the phenomena much bother him, or defined.'s where we come across the alignment of Fernando Pessoa within philosophical as occultism and reading about psychological and mental disorders treated. paths were pursued by him to explain the existence of his heteronyms and its entry process. This work therefore presents main objective: to analyze the personal papers of Fernando Pessoa, whose outstanding feature is the presence of occult and alleged mediumship demonstrations held in response to non-literary and heteronímicas. Therefore, I focused on specific goals, which are: a) to study the speech of Fernando Pessoa on his mediumship / occult b) analyzing specific texts that are, for the poet, psychic demonstrations, c) study of a series of excerpts personal letters in which Fernando Pessoa suggested to be a medium. Admittedly, this essay will touch many arguments already made by scholars and experts of Fernando Pessoa, but consider the possibility of developing issues and contribute to the critical fortune of the poet. We assume that announces the Portuguese scholar Jerome Pizarro (2006), one of the greatest scholars of the work Pessoan: those interested in Fernando Pessoa be lost in the maze created by him. It is the image of a person-Minotaur, devouring all but, holding us in its labyrinthine tessitura, as marked by mystery. Will draw on our analysis, a theory aligned themselves to objects of research, whose main authors are Sigmund Freud (1908) Carl Jung (1991.1996). Gaston Bachelard (1996), Helena Blavatsky (2008), among others

Taxa de disparo e ativação de assembléias no hipocampo de ratos durante o processamento de uma memória aversiva

Hebb postulated that memory could be stored thanks to the synchronous activity of many neurons, building a neural assembly. Knowing of the importance of the hippocampal structure to the formation of new explicit memories, we used electrophysiological recording of multiple neurons to access the relevance of rate coding from neural firing rates in comparison to the temporal coding of neural assemblies activity in the consolidation of an aversive memory in rats. Animals were trained at the discriminative avoidance task using a modified elevated plus-maze. During experimental sessions, slow wave sleep periods (SWS) were recorded. Our results show an increase in the identified neural assemblies activity during post-training SWS, but not for the neural firing rate. In summary, we demonstrate that for this particular task, the relevant information needed for a proper memory consolidation lies within the temporal patters of synchronized neural activity, not in its firing rate

Avaliação comportamental e neuroquímica de ratos em dessincronização forçada: possíveis implicações para um modelo animal de oscilações no humor

Bipolar disorder has been growing in several countries. It is a disease with high mortality and has been responsible by the social isolation of the patients. Bipolar patients have alterations in circadian timing system, showing a phase shift in various physiological variables. There are several arguments demonstrating alterations in circadian rhythms may be part of the bipolar disorder pathophysiology. Given the necessity for further elucidation, the goal of this study was to validate the forced desynchronization protocol as an animal model for bipolar disorder. To do this, Wistar rats were submitted to a forced desynchronization protocol which consists in a symmetrical light dark cycle with 22h. Under this protocol, rats dissociate the locomotor activity rhythm into two components: one synchronized to the light / dark cycle with 22h, and another component with period longer than 24 hours following the animal endogenous period. These rhythms with different periods sometimes there is coincidence, which we named CAP (Coincidence Active Phase) and the opposite phase, non-coincidence, called NCAP (Non-Concidence Active Phase). The hypothesis is that in CAP animals present a mania-like behavior and animals in NCAP depressive-like behavior. We found some evidence described in detail throughout this thesis. In sum, the animals under forced desynchronization protocol were more stressed, showed an increase in stereotypic behaviors such as grooming and reduction in other behaviors such as risk assessment and vertical exploration when compared to the control group. The CAP animals showed increased locomotor activity, especially during the dark phase when compared to controls (rats under T24) and less depressive behavior in the forced swim test. The animals in NCAP showed a higher anxiety in elevated plus maze, but they don t have ahnedonia. The animals under dissociation have more labeled 5HT1A cells at the amygdala area, which appoint that they have more amygdala inhibition. Taking these data together, we could partially validated the forced desynchronization protocol as an animal model for mood oscillations

Oscilações Teta no hipocampo do rato durante tarefa de tomada de decisão espacial

The processing of spatial and episodic information during memory tasks depends on hippocampal theta oscillations. In the present study, I investigated the relationship between theta power and choice selection during spatial decision-making. I recorded local field potentials from the CA1 region of rats retrieving reward locations in a 4-arm maze. In trained but not in naïve animals, I observed a significant increase in theta power during decision-making, which could not be explained by changes in locomotion speed. Furthermore, a Bayesian decoder based on theta power predicted choice outcomes in speed-matched trials. The decoding time course revealed that performance increased above chance before the decision moment exclusively for theta power, remaining flat for other frequency bands. These results occurred for trained animals, but no significant prediction could be made for naïve animals. Altogether, the data support a mnemonic function of theta rhythm during spatial decision-making, indicating that these oscillations correlate with the retrieval of memories required for successful decisions

Efeitos dos esteroides anabólicos androgênicos sobre funções cognitivas de ratos

The use and the demand for substances that enhance masculinity, strength and sexual power are not novel. Over the years, this search has assisted the research directions in this area, leading to the discovery of the primary male sex hormone testosterone in 1935. Since then, numerous testosterone analogue compounds were synthesized, which are generically called Anabolic Androgenic Steroids (AAS). The AAS were produced for therapeutic purposes, but an increase in the use of these compounds for other purposes occurred over time. Initially they were used mainly to improve performance in athletes. However, recent studies have shown that the use of AAS by non-athletes with aesthetical purposes have been increasing as well. The abuse of AAS with non-clinical purposes can promote a number of physiological alterations, such as heart, liver, respiratory and psychological problems such as changes in mood, levels of anxiety and aggression. Exposure to supraphysiological doses of AAS is associated with behavioral changes, however, little is known about the effects of AAS on cognitive functions. In this work, we aimed to mimic the AAS abuse in humans with intramuscular administration of a supraphysiological dose of testosterone propionate (TP) in rats. We investigated the effects of this treatment on different aspects of cognitive function, specifically learning, memory and anxiety. Adult male Wistar rats were tested in the spontaneous alternation, novel object recognition and plus-maze discriminative avoidance tasks. The control group received intramuscular injections of vegetable oil (vehicle), and the TP group received injections of TP (10 mg/kg, i.m.). The injections were administered for 40 days, with intervals of 48 hours (chronic treatment) or in a single injection (acute treatment). In addition to the behavioral assessments, we performed biochemical analyzes as indicators of the endocrine effects of the treatment. Our results show that chronic treatment with a supraphysiological dose of TP caused memory impairments in the novel object recognition and the discriminative avoidance tasks. The spatial working memory (evaluated by spontaneous alternation task) was not affected. Also, we did not observe changes in anxiety levels. Regarding the biochemical parameters, chronic treatment increased serum levels of glutamicpyruvic transaminase, an indicator of hepatic and pancreatic lesions (as those observed after chronic use of these substances in humans). On the other hand, acute treatment with PT did not promote significant changes in any of these parameters when compared to the control group. In summary, we conclude that chronic treatment with a supraphysiological dose of testosterone propionate produces memory deficits in novel object recognition and retrieval of the discriminative avoidance task in adult male rats

Efeitos da alteração dos níveis de ansiedade no desempenho de ratos em uma tarefa de discriminação apetitiva

The plus-maze discriminative avoidance paradigm has been used to study the relationship between aversive memory and anxiety. The present study aims to verify if the elevated plus-maze can provide information about appetitive memory and anxiety, through a task motivated by food reward. Animals were allowed to explore an elevated plus-maze and received reinforcement in one of the enclosed arms. In a test session performed 24h later, in the absence of reward, rats showed preference for the previously rewarded enclosed arm over the neutral enclosed arm. The administration of diazepam and pentylenetetrazole before training induced, respectively, anxiolytic and anxiogenic effects (as evaluated by open-arm exploration). Both drugs induced amnestic effects, i.e., lack of preference for the rewarded arm in the test session. The results suggest that appetitive memory can be influenced by anxiety levels as well. The plus-maze appetitive discrimination task seems to be a useful model to investigate the relationship between memory and anxiety

Expressão de zif-268 durante a aquisição, evocação e extinção de uma memória aversiva

In the behavioral paradigm of discriminative avoidance task, both short and long-term memories have been extensively investigated with behavioral and pharmacological approaches. The aim of the present study was to evaluate, using the abovementioned model, the hippocampal expression of zif-268 - a calcium-dependent immediate early gene involved with synaptic plasticity process - throughout several steps of memory formation, such as acquisition, evocation and extiction. The behavioral apparatus consisted of a modified elevaated plus-maze, with their enclosed arms disposed in "L". A pre-exposure to the maze was made with the animal using all arms enclosed, for 30 minutes, followed by training and test, during 10 minutes each. The between sections interval was 24h. During training, aversive stimuli (bright light and loud noise) were actived whenever the animals entered one of the enclosed armas (aversive arm). Memory acquisiton, retention and extinction were evaluated by the percentage of the total time spent exploring the aversive arm. The parameters evaluated (time spent in the arms and total distance traveled) were estimated with an animal tracking software (Anymaze, Stoelting, USA). Learning during training was estimated by the decrease of the time spent exploring the aversive arm. One hour after the beginning of each section, animals were anaesthetized with sodium-thiopental (i.p.) and perfused with 0.9% heparinized saline solution followed by 4% paraformaldehyde. Brains were cryoprotected with 20% sucrose, separeted in three blocks and frozen. The middle block, containing the hippocampus, was sectioned at 20 micro meters in the coronal plane and the resutant sections were submitted to zif-268 immunohistochemistry. Our results show an increased expression of zif-268 in the dentate gyrus (DG) during the evocation and extinction stages. There is a distinct participation of the DG during the memory evocation, but not during its acquisition. Inaddition, all hippocampal regions (CA1, CA3 and DG) presented an increased zif-268 expression during the process of extinction.

Neurofisiologia hipocampal durante sessões de sono intercaladas por exploração espacial: Reverberação do passado ou predição do futuro?

The ability to predict future rewards or threats is crucial for survival. Recent studies have addressed future event prediction by the hippocampus. Hippocampal neurons exhibit robust selectivity for spatial location. Thus, the activity of hippocampal neurons represents a cognitive map of space during navigation as well as during planning and recall. Spatial selectivity allows the hippocampus to be involved in the formation of spatial and episodic memories, including the sequential ordering of events. On the other hand, the discovery of reverberatory activity in multiple forebrain areas during slow wave and REM sleep underscored the role of sleep on the consolidation of recently acquired memory traces. To this date, there are no studies addressing whether neuronal activity in the hippocampus during sleep can predict regular environmental shifts. The aim of the present study was to investigate the activity of neuronal populations in the hippocampus during sleep sessions intercalated by spatial exploration periods, in which the location of reward changed in a predictable way. To this end, we performed the chronic implantation of 32-channel multielectrode arrays in the CA1 regions of the hippocampus in three male rats of the Wistar strain. In order to activate different neuronal subgroups at each cycle of the task, we exposed the animals to four spatial exploration sessions in a 4-arm elevated maze in which reward was delivered in a single arm per session. Reward location changed regularly at every session in a clockwise manner, traversing all the arms at the end of the daily recordings. Animals were recorded from 2-12 consecutive days. During spatial exploration of the 4-arm elevated maze, 67,5% of the recorded neurons showed firing rate differences across the maze arms. Furthermore, an average of 42% of the neurons showed increased correlation (R>0.3) between neuronal pairs in each arm. This allowed us to sort representative neuronal subgroups for each maze arm, and to analyze the activity of these subgroups across sleep sessions. We found that neuronal subgroups sorted by firing rate differences during spatial exploration sustained these differences across sleep sessions. This was not the case with neuronal subgroups sorted according to synchrony (correlation). In addition, the correlation levels between sleep sessions and waking patterns sampled in each arm were larger for the entire population of neurons than for the rate or synchrony subgroups. Neuronal activity during sleep of the entire neuronal population or subgroups did not show different correlations among the four arm mazes. On the other hand, we verified that neuronal activity during pre-exploration sleep sessions was significantly more similar to the activity patterns of the target arm than neuronal activity during pre-exploration sleep sessions. In other words, neuronal activity during sleep that precedes the task reflects more strongly the location of reward than neuronal activity during sleep that follows the task. Our results suggest that neuronal activity during sleep can predict regular environmental changes

Antidepressivos modificam a extinção de uma memória aversiva em ratas

Treatment of major depression, posttraumatic stress disorder and other psychopathologies with antidepressants can be associated with improvement of the cognitive deficits related to these disorders. Although the mechanisms of these effects are not completely elucidated, alterations in extinction of aversive memories are believed to be present in these psychopathologies. Moreover, researches with laboratory animals usually focus on male subjects, and we have recently verified that extinction of an aversive task is reduced in female rats when compared to males. In the present study, female rats were long-term treated with clinically used antidepressants (fluoxetine, nortriptyline or mirtazapine) and tested in the plus-maze discriminative avoidance and forced swimming tests in order to evaluate learning, memory, extinction, anxiety and depression-related behaviors. All groups learned the task, but learning was somewhat faster in nortriptyline and mirtazapine-treated animals . Task retrieval was also showed by all experimental groups. Chronic treatment with fluoxetine, but not with the other antidepressants, increased extinction of the discriminative task. In the forced swimming test, animals treated with fluoxetine and mirtazapine showed decreased immobility duration. In conclusion, antidepressants interfere with learning and female rats treated with fluoxetine presented increased extinction of the aversive memory task. On the other hand, both fluoxetine and mirtazapine were effective in the forced swimming test, suggesting dissociation between the antidepressant effects and the extinction of aversive memories

Influência do ciclo estral no efeito do diazepam na ansiedade e memória de ratas

Memory and anxiety are related phenomena. Several evidences suggest that anxiety is fundamental for learnining and may facilitate or impair the memory formation process depending of the context. The majority of animal studies of anxiety and fear use only males as experimental subjects, while studies with females are rare in the literature. However, the prevalence in phobic and anxiety disorders is greater in women than in men. Moreover, it is known that gender maybe influence benzodiazepine effects, the classic drugs used for anxiety disorders treatment. In this respect, to further investigate if fear/anxiety aspects related to learning in female subjects would contribute to the study of phobic and anxiety disorders and their relationship with learning/memory processes, the present work investigates (a) the effects of benzodiazepine diazepam on female rats performance in a aversive memory task that assess concomitantly anxiety/emotionality, as the interaction between both; (b) the influence of estrous cycle phases of female rats on diazepam effects at aversive memory and anxiety/emotionality, and the interaction between both and (c) the role of hormonal fluctuations during estrous cycle phases in absence of diazepam effects in proestrus, because female rats in this phase received or not mifepristone, the antagonist of progesterone receptor, previously to the diazepam treatment. For this purpose, the plus maze discriminative avoidance task, previously validated for studies of anxiety concomitantly to learning/memory, was used. The apparatus employed is an adaptation of a conventional plus maze, with two opens arms and two closed arms, one of which presenting aversive stimulation (noise and light). The parameters used were: time in non-aversive arm compared to time in aversive and percentage of time in aversive arm on several temporal divisions, in order to evaluate memory; percentage of time in open arms, risk assessment, head dipping and end exploring to evaluate anxiety ; and distance traveled for locomotion. In experiment I, we found anxiolytic effect of diazepam only for 4 mg/kg dose, however the amnestic effect appear at a dose of 2 mg/kg. In second experiment, rats were divided in groups according estrous cycle phase (metaestrus/diestrus, proestrus e estrus). In this experiment, when we considered estrous cycle phase or diazepam treatment, the results did not demonstrate any differences in anxiety/emotionality parameters. The amnestic effects of diazepam occur in female rats in metestrus/diestrus and estrus and is absent in proestrous rats. Proestrous female rats that received mifepristone exhibited the amnestic effect of diazepam and also anxiolytic effects, that it was not previously observed in this dose. The results have demonstrated dissociation of anxiolytic and amnestic diazepam effects, not previously observed in males; the absence of amnestic effect of diazepam in proestrous phase; and the possible role of progesterone in aversive memory over diazepam effect, because the mifepristone, associated with diazepam, caused amnestic effect in proestrus

Avaliação dos efeitos do biperideno, diazepam e neuropeptídeos S sobre a memória e a ansiedade na tarefa do labirinto em T elevado em camundongos

Anxiety is an emotional phenomenon, and normally it is interpreted as an adaptative behavior front to adversities. In its pathological form, anxiety can severely affect aspects related to the personal and professional life. Studies have shown a close relationship between anxiety disorders and aversive memory processing. Considering that the pharmacotherapy of anxiety disorders is still limited, innovative anxiolytic agents are needed. In this regard, neuropeptides systems are interesting therapeutic targets to the treatment of psychopathologies. Neuropeptide S (NPS), a 20-aminoacid peptide, is the endogenous ligand of a G-protein coupled receptor (NPSR), which has been reported to evoke hyperlocomotion, awakefull states, besides anxiolysis and memory improvements in rodents. This study aimed to investigate the effects of biperiden (BPR; an amnesic drug), diazepam (DZP; an anxiolytic drug) and NPS at three distinct times: pre-training, post-training, and pre-test, in order to assess anxiety and memory process in the same animal model. The elevated Tmaze (ETM) is an apparatus derived from the elevated plus-maze test, which consists of one enclosed and two open arms. The procedure is based on the avoidance of open spaces learned during training session, in which mice were exposed to the enclosed arm as many times as needed to stay 300 s. In the test session, memory is assessed by re-exposing the mouse to the enclosed arm and the latency to enter an open arm was recorded. When injected pre-training, BPR (1 mg/kg) impaired learning and memory processing; DZP (1 and 2 mg/kg) evoked anxiolysis, but only at the dose of 2 mg/kg impaired memory; and NPS 0.1 nmol induced anxiolysis without affecting memory. Post-training injection of DZP (2 mg/kg) or BPR (1 and 3 mg/kg) did not affect memory consolidation, while the post-trainning administration of NPS 1 nmol, but not 0.1 nmol, improved memory in mice. Indeed, pre-trainning administration of NPS 1 nmol did not prevent memory impairment elicited by BPR (2 mg/kg, injected before training). In the open field test, BPR 1 mg/kg and NPS 1 nmol induced hyperlocomotion in mice. In conclusion, the proposed ETM task is practical for the detection of the anxiolytic and amnesic effects of drugs. The anxiolytic and memory enhancement effects of NPS were detected in the ETM task, and reinforce the role of NPS system as an interesting therapeutic target to the treatment of anxiety disorders