Object Exploration Research Articles

Translational potential of JAX hAPOE AD mouse model: Phenotypic characterization of cognitive function and amyloid beta

AbstractBackgroundAPOEe4 is the greatest genetic risk factor for late onset Alzheimer’s Disease (LOAD). The product of this gene, apolipoprotein E isoform ε4, has been characterized as a lipid transporter and many of its receptors and mechanisms have been identified. Studies have shown that APOEe4 exacerbates accumulation of Aβ peptides and correlates with a decline in cognitive function in humans. We investigated the translational feasibility of the humanized APOE3 (JAX #029018) and APOE4 (JAX #027894) mouse model on two hallmark pathologies of LOAD: cognitive decline and b‐amyloid (Aβ) generation in brain.MethodNovel object recognition (NOR), open field (OF), and CatWalk analyses were conducted in 18 month old transgenic mice with humanized APOEe3 homozygous (B6(SJL)‐ApoEtm1.1(APOE*3)Adiuj/J), APOEe3/4, or APOEe4 homozygous genes (B6(SJL)‐ApoEtm1.1(APOE*4)Adiuj/J). NOR analyses included discrimination index, OF center zone time, whereas CatWalk included mobility measures including cadence and speed. Aβ38, Aβ40, and Aβ42 analyses were assessed in brain and plasma.ResultNo differences were detected in NOR discrimination index, NOR combined object exploration time, or OF center zone time across sex or genotype. OF mean speed was lower in APOE3/4 mice compared to APOE4 mice. Aβ38 was not detected in any group. Hippocampal Aβ42 was significantly lower in APOE3/4 mice compared to APOE4 and APOE3 mice. No differences were detected in hippocampal Aβ40 or Aβ42/40 ratios. Plasma Aβ40, Aβ42, and Aβ42/40 were lower in females relative to males. Analyses based on sex and genotype indicated that plasma Aβ40 and Aβ42 were lower in APOE3 females vs APOE3 males, and Aβ42/40 was lower in APOE3 females vs every other group.ConclusionAPOE3/4 heterozygosity may confer a protective effect against Aβ42 deposition in the hippocampus, and female APOE mice consistently exhibit lower plasma Aβ. Translational applicability to humans on measures of cognitive decline and hippocampal Aβ42 deposition at 18 months (human age equivalent ∼56 years) for APOE mice is limited.Acknowledgements: Research supported by NIA R01AG57931 and RF1AG059093

메타버스 시대의 문화예술교육

The most popular digital concept due to the recent development of digital technology is 'metaverse'. In particular, these days, when non-face-to-face communication methods are desperately needed due to the post-corona era, the concept of metaverse has come very close to us and is causing a syndrome. Metaverse is a cutting-edge technology of digital technology that changes the paradigm of communication and relationships in the present age and is a concept that is very suitable for the post-corona era. In this study, the applicability of Culture and Arts Education in the metaverse era was suggested as follows. First, virtual reality technology can be used as a mechanism to expand cultural and artistic experiences and trial. Second, the expressive activity of learners through virtual reality can improve media utilization ability and foster empathy through storytelling composition work. Third, virtual reality can be used as a method of building tools and materials for observation, exploration, and appreciation of objects. Lastly, virtual reality technology can construct and build various virtual worlds.

Developmental trajectory of episodic-like memory in rats.

Episodic memory formation requires the binding of multiple associations to a coherent episodic representation, with rich detail of times, places, and contextual information. During postnatal development, the ability to recall episodic memories emerges later than other types of memory such as object recognition. However, the precise developmental trajectory of episodic memory, from weaning to adulthood has not yet been established in rats. Spontaneous object exploration tasks do not require training, and allow repeated testing of subjects, provided novel objects are used on each trial. Therefore, these tasks are ideally suited for the study of the ontogeny of episodic memory and its constituents (e.g., object, spatial, and contextual memory). In the present study, we used four spontaneous short-term object exploration tasks over two days: object (OR), object-context (OCR), object-place (OPR), and object-place-context (OPCR) recognition to characterise the ontogeny of episodic-like memory and its components in three commonly used outbred rat strains (Lister Hooded, Long Evans Hooded, and Sprague Dawley). In longitudinal studies starting at 3-4 weeks of age, we observed that short term memory for objects was already present at the earliest time point we tested, indicating that it is established before the end of the third week of life (consistent with several other reports). Object-context memory developed during the fifth week of life, while both object-in-place and the episodic-like object-place-context memory developed around the seventh postnatal week. To control for the effects of previous experience in the development of associative memory, we confirmed these developmental trajectories using a cross-sectional protocol. Our work provides robust evidence for different developmental trajectories of recognition memory in rats depending on the content and/or complexity of the associations and emphasises the utility of spontaneous object exploration tasks to assess the ontogeny of memory systems with high temporal resolution.

Cooperation vs. affiliation: an exploratory qualitative study of alcoholics anonymous’ position within the recovery ecosystem

Background Addressing substance use disorder (SUD) requires intricate solutions, usually involving several organizations within a complex institutional environment. Alcoholics Anonymous (AA) shares the recovery ecosystem with other organizations, is ubiquitous across communities, and is notably inexpensive as an intervention; yet the exact nature of the connections between AA and other organizations in the recovery ecosystem is underexplored. Objective Explore relationships AA has with other recovery ecosystem organizations and guide future research. Methods Data were gathered via ethnographic participant observations, which were triangulated and contextualized via semi-structured interviews with key informants and archival documents. Results Though AA does not formally link itself with other organizations, findings point toward strong relationships at the individual level and of an informal nature. Individual members who also have affiliation with other organizations (e.g., legal institutions, treatment services) create bridges, enabling efficient solving of complex issues. Conclusions Services wishing to leverage AA (or other mutual-aid) attendance will likely benefit from fostering informal relationships with individual AA members, including lowering barriers to disclosure of recovery status, and contacting local AA service elements capable of making these connections. Similarly, research to advance community-level SUD services and the knowledge-base would benefit from incorporating and partnering with people in recovery.

Gaze-contingent display technology can help to reduce the ipsilesional attention bias in hemispatial neglect following stroke

BackgroundHemispatial neglect results from unilateral brain damage and represents a disabling unawareness for objects in the hemispace opposite the brain lesion (contralesional). The patients’ attentional bias for ipsilesional hemispace represents a hallmark of neglect, which results from an imbalanced attentional priority map in the brain. The aim of this study was to investigate whether gaze-contingent display (GCD) technology, reducing the visual salience of objects in ipsilesional hemispace, is able to rebalance this map and increase awareness and exploration of objects in the neglected contralesional hemispace.MethodsUsing remote eye-tracking, we recorded gaze positions in 19 patients with left hemispatial neglect following right-hemisphere stroke and 22 healthy control subjects, while they were watching static naturalistic scenes. There were two task conditions, free viewing (FV) or goal-directed visual search (VS), and four modification conditions including the unmodified original picture, a purely static modification and two differently strong modifications with an additional gaze-contingent mask (GC-LOW, GC-HIGH), that continuously reduced color saturation and contrast of objects in the right hemispace.ResultsThe patients’ median gaze position (Center of Fixation) in the original pictures was markedly deviated to the right in both tasks (FV: 6.8° ± 0.8; VS: 5.5° ± 0.7), reflecting the neglect-typical ipsilesional attention bias. GC modification significantly reduced this bias in FV (GC-HIGH: d = − 3.2 ± 0.4°; p < 0.001). Furthermore, in FV and VS, GC modification increased the likelihood to start visual exploration in the (neglected) left hemifield by about 20%. This alleviation of the ipsilesional fixation bias was not associated with an improvement in detecting left-side targets, in contrast, the GC mask even decreased and slowed the detection of right-side targets. Subjectively, patients found the intervention pleasant and most of the patients did not notice any modification.ConclusionsGCD technology can be used to positively influence visual exploration patterns in patients with hemispatial neglect. Despite an alleviation of the neglect-related ipsilesional fixation bias, a concomitant functional benefit (improved detection of contralesional targets) was not achieved. Future studies may investigate individualized GCD-based modifications as augmented reality applications during the activities of daily living.

Is the volume of Burch urethropexy sufficient for urogynecology fellows to meet the ACGME requirement?

Urogynecology fellows report low exposure to nonsling retropubic anti-incontinence procedures such as Burch urethropexy and thus may have difficulty meeting the required minimum case numbers, but there has been an even more objective exploration of this observation. Thus, our objective was to assess the feasibility of meeting the Accreditation Council for Graduate Medical Education (ACGME) requirement for each urogynecology fellow to perform five nonsling retropubic anti-incontinence procedures during fellowship. Cross-sectional study using the National Surgical Quality Improvement Program (NSQIP) and National Resident Matching Program (NRMP) databases from 2009 to 2019. From NSQIP, the number of nonsling retropubic anti-incontinence procedures (open and laparoscopic Burch urethropexy and bladder neck needle suspension) and midurethral sling procedures was extracted using CPT codes. The number of fellows was extracted from the NRMP database. Trends in the number of anti-incontinence procedures were compared with the trend in the number of fellows using linear regression. From 2009 to 2019 the number of fellows doubled from 81 to 176. An average of 97 nonsling retropubic anti-incontinence and 6,372 sling procedures were performed annually. Linear regression showed an increase of 10.7 fellows per year (95% CI 9.3-12.1) versus an increase of 5.8 nonsling retropubic anti-incontinence procedures per year (95% CI -0.4 to 12.1). This contrasts with an increase of 690.9 slings per year (95% CI 509.9-872.0). The increase in the number of nonsling retropubic anti-incontinence procedures does not appear to match the increase in the number of urogynecology fellows. Supplementary educational approaches such as simulation may be prudent.

Teacher Action and Student Action in Mathematics Classes Based on the Exploration of Learning Objects on Digital Board: Categorisations and Connections

Background: The methods by which mathematics content can be taught and learned using technologies and how they condition the production of mathematical knowledge have usually been the subject of our research. These investigations have allowed us to describe, understand and analyse the educational context in which we researchers are inserted, also allowing us to highlight the teacher’s and the students’ actions, their categorisations, and connections during the implementation of classes. These reasons motivated us to carry out this investigation. Objectives: To characterise the teacher’s and the students’ actions, highlighting their connections. Design: Qualitative research based on content analysis. Setting and participants: The research subjects were 1 teacher; 24 elementary school students, 10 students of the 6th grade and 14 of the 7th grade, and 12 high-school 3rd graders, all enrolled in the Paraná state network. Data collection and analysis: The actions were captured through field notes and video recordings, later transcribed. Results: In view of the information collected and the analyses carried out, 22 categories were evidenced for the teacher’s action and 40 categories for the student’s action. Conclusions: We proved that some of the teacher's actions triggered several other students’ actions. However, we identified three categories of students’ actions unrelated to the teacher’s actions nor to the performance of the activity provided by the learning objects. In fact, such actions were provided by the learning environment in which students used technological resources.

Fentanyl Induces Novel Conditioned Place Preference in Adult Zebrafish, Disrupts Neurotransmitter Homeostasis, and Triggers Behavioral Changes.

Abuse of new psychoactive substances increases risk of addiction, which can lead to serious brain disorders. Fentanyl is a synthetic opioid commonly used in clinical practice, and behavioral changes resulting from fentanyl addiction have rarely been studied with zebrafish models. In this study, we evaluated the rewarding effects of intraperitoneal injections of fentanyl at concentrations of 10, 100, and 1000 mg/L on the group shoaling behavior in adult zebrafish. Additional behavioral tests on individual zebrafish, including novel tank, novel object exploration, mirror attack, social preference, and T-maze memory, were utilized to evaluate fentanyl-induced neuro-behavioral toxicity. The high doses of 1000 mg/L fentanyl produced significant reward effects in zebrafish and altered the neuro-behavioral profiles: reduced cohesion in shoaling behavior, decreased anxiety levels, reduced exploratory behavior, increased aggression behavior, affected social preference, and suppressed memory in an appetitive associative learning task. Behavioral changes in zebrafish were shown to be associated with altered neurotransmitters, such as elevated glutamine (Gln), gamma-aminobutyric acid (GABA), dopamine hydrochloride (DA), and 5-hydroxytryptamine (5-HT). This study identified potential fentanyl-induced neurotoxicity through multiple neurobehavioral assessments, which provided a method for assessing risk of addiction to new psychoactive substances.

The socially enriched environment test: a new approach to evaluate social behavior in a mouse model of social anxiety disorder.

Social anxiety disorder (SAD) is a common anxiety disorder characterized by a marked fear of social situations. Treatments for SAD, including exposure therapy and medication, are not satisfactory for all patients. This has led to the development of several paradigms to study social fear in rodents. However, there are still some social impairments observed in SAD patients that have never been examined in rodent models. Indeed, social situations avoided by SAD patients include not only social interactions but also public performances and being observed by others. Nevertheless, tests used to assess sociability in rodents evaluate mostly social interaction in pairs. Thus, we developed a new test-a socially enriched environment test-that evaluates sociability within a group of three unfamiliar conspecifics in an enriched environment. In this study, we induced a SAD-like behavior (i.e., social fear) in male mice using social fear conditioning (SFC) and then tested social fear using the socially enriched environment test and the three-chamber test. Finally, we tested the effects of fear extinction and acute diazepam treatment in reversing social fear. Results revealed, in conditioned mice, decreased object exploration in proximity to conspecifics, social interaction, and mouse-like object exploration. Extinction training, but not acute diazepam treatment, reversed SFC-induced behavioral changes. These findings demonstrate that the socially enriched environment test provides an appropriate behavioral approach to better understand the etiology of SAD. This test may also have important implications in the exploration of new treatments.

The Effect of START-Play Intervention on Reaching-Related Exploratory Behaviors in Children with Neuromotor Delays: A Secondary Analysis of a Randomized Controlled Trial

Aims Children with neuromotor delays are at risk for reaching and object exploration impairments, which may negatively affect their cognitive development and daily activity performance. This study evaluated the effectiveness of the Sitting Together And Reaching To Play (START-Play) intervention on reaching-related exploratory behaviors in children with neuromotor delays. Methods In this randomized controlled clinical trial, 112 children (Mean = 10.80, SD = 2.59 months old at baseline) with motor delays were randomly assigned to receive START-Play intervention or usual care-early intervention. Performance for ten reaching-related exploratory behaviors was assessed at baseline and 1.5, 3, 6, 12 months post-baseline. Piecewise linear mixed-effects modeling was used to evaluate short- and long-term effects of the intervention. Results Benefits of START-Play were observed for children with significant motor delays, but not for those with mild delays. START-Play was especially beneficial for children with significant motor delays who demonstrated early mastery in the reaching assessment (i.e., object contact ≥65% of the time within 3 months after baseline); these children showed greater improvements in manual, visual, and multimodal exploration, as well as intensity of exploration across time. Conclusions START-Play advanced the performance of reaching-related exploratory behaviors in children with significant motor delays.

Spontaneous object recognition in capuchin monkeys: assessing the effects of sex, familiarization phase and retention delay.

The spontaneous object recognition (SOR) task is a versatile and widely used memory test that was only recently established in nonhuman primates (marmosets). Here, we extended these initial findings by assessing the performance of adult capuchin monkeys on the SOR task and three potentially intervening task parameters-object familiarization phase, retention delay and sex. In Experiment 1, after an initial 10-min familiarization period with two identical objects and a pre-established retention delay (0.5, 6 or 24h), the capuchins preferentially explored a new rather than the familiar object during a 10-min test trial, regardless of delay length. In Experiment 2, the capuchins were again exposed to two identical objects (but now for 10 or 20 min), then a 30-min retention delay and a 10-min test trial. An exploratory preference for the new over the familiar item was not affected by the length of the familiarization interval, possibly because overall exploration remained the same. However, the amount of initial object exploration was not related to task performance, and both males and females performed similarly on the SOR task with a 10-min familiarization, 30-min delay and 10-min test trial. Therefore, male and female capuchins recognize objects on the SOR task after both short and long delays, whereas a twofold increase in the familiarization phase does not affect task performance. The results also provide further support for the use of incidental learning paradigms to assess recognition memory in nonhuman primates.

A Biomimetic Tactile Palm for Robotic Object Manipulation

Tactile sensing plays a vital role for human hand function in terms of object exploration, grasping and manipulation. Different types of tactile sensors have been designed during the past decades, which are mainly focused on either the fingertips for grasping or the upper-body for human-robot interaction. In this letter, a novel soft tactile sensor has been designed to mimic the functionality of human palm that can estimate the contact state of different objects. The tactile palm mainly consists of three parts including an electrode array, a soft cover skin and the liquid resistance between them. The design principle and the fabrication process are described in details, with a number of experiments showcasing the effectiveness of the proposed design.

Voices from teaching experience and management in academic life

This paper discusses teaching work against the background of critically understanding the tensions that permeate the work process of higher education faculty, considering, centrally, the exercise of management activities related to positions of leadership, coordination or direction and representation in collegiate bodies in University. The research problem is linked to the author's professional practice in view of the perceived silence regarding the work of higher education professors in these activities. As a strategy to achieve the general objective of the research, it was sought to understand teaching work and the place that academic management occupies in its professionality, identifying the implications of the training process in the practice of the profession. In a qualitative approach, the study was developed through the analysis of Memories of Promotion to Full Professor of five professors from an Academic Unit of the Federal University of Minas Gerais. The investigation had Narrative Research as its methodological choice and as object of analysis the narratives of the professors of higher education to understand the experience from the perspective of management. Bardin's Content Analysis (2008) was used as a method to operationalize the exploration of the research object, as well as the treatment of results. The research results recognize that professionals in higher education face the challenge of being a teacher-researcher-manager on a daily basis within the logic of capitalist society, permeated by contradictions that are expressed in the education and work of this professional.

Early blindness modulates haptic object recognition.

Haptic object recognition is usually an efficient process although slower and less accurate than its visual counterpart. The early loss of vision imposes a greater reliance on haptic perception for recognition compared to the sighted. Therefore, we may expect that congenitally blind persons could recognize objects through touch more quickly and accurately than late blind or sighted people. However, the literature provided mixed results. Furthermore, most of the studies on haptic object recognition focused on performance, devoting little attention to the exploration procedures that conducted to that performance. In this study, we used iCube, an instrumented cube recording its orientation in space as well as the location of the points of contact on its faces. Three groups of congenitally blind, late blind and age and gender-matched blindfolded sighted participants were asked to explore the cube faces where little pins were positioned in varying number. Participants were required to explore the cube twice, reporting whether the cube was the same or it differed in pins disposition. Results showed that recognition accuracy was not modulated by the level of visual ability. However, congenitally blind touched more cells simultaneously while exploring the faces and changed more the pattern of touched cells from one recording sample to the next than late blind and sighted. Furthermore, the number of simultaneously touched cells negatively correlated with exploration duration. These findings indicate that early blindness shapes haptic exploration of objects that can be held in hands.

Lithium produces bi-directionally regulation of mood disturbance, acts synergistically with anti-depressive/-manic agents, and did not deteriorate the cognitive impairment in murine model of bipolar disorder

Lithium (Li) is a well-established mood disorder treatment and may be neuroprotective. Bi-directional regulation (i.e. affecting manic symptoms and depressive symptoms) by Li has not been demonstrated. This study explored: (1) bidirectional regulation by Li in murine models of depression, mania, and bipolar disorder (BP); and (2) potential Li synergism with antidepressant/anti-mania agents. The chronic unpredictable mild stress (CUMS) and ketamine-induced mania (KM) models were used. These methods were used in series to produce a BP model. In vivo two-photon imaging was used to visualize Ca2+ activity in the dorsolateral prefrontal cortex. Depressiveness, mania, and cognitive function were assessed with the forced swim task (FST), open field activity (OFA) task, and novel object recognition task, respectively. In CUMS mice, Ca2+ activity was increased strongly by Li and weakly by lamotrigine (LTG) or valproate (VPA), and LTG co-administration reduced Li and VPA monotherapy effects; depressive immobility in the FST was attenuated by Li or LTG, and attenuated more strongly by LTG-VPA or LTG-Li; novel object exploration was increased strongly by Li and weakly by LTG-Li, and reduced by LTG, VPA, or LTG-VPA. In KM mice, Li or VPA attenuated OFA mania symptoms and normalized Ca2+ activity partially; Li improved cognitive function while VPA exacerbated the KM alteration. These patterns were replicated in the respective BP model phases. Lithium had bi-directional, albeit weak, mood regulation effects and a cognitive supporting effect. Li co-administration with antidepressant/-manic agents enhanced mood-regulatory efficacy while attenuating their cognitive-impairing effects.

Ears of the past, an inquiry into the sonic memory of the acoustics of Notre-Dame before the fire of 2019

This interdisciplinary study brings together acousticians and anthropologists to examine the memory of the acoustics of Notre-Dame de Paris before the fire of April 2019, using a qualitative approach to collect the testimonies of 18 people involved in the sound usages of the cathedral. Testimonies were analyzed in light of research conducted in the anthropology of the senses, sensory perception, memory, and cultural heritage. Analysis highlights an apparent contradiction between the remarkable acoustics of the monument before the fire and the impression of musicians. These musicians reported a struggle to tame the cathedral’s sound space, to hear each other well enough to craft their performances and to reach an acceptable level of clarity in their musical practice. These phenomena are examined with acoustic measurements and numerical simulations using a calibrated geometrical acoustics model of the cathedral before the fire, which allows for an objective exploration of the acoustic characteristics of Notre-Dame. This analysis concludes that the well-known reverberation of Notre-Dame, as well as the acoustic barrier of the transept and the poor acoustic return on the podium (the usual place for concert performers) negatively impact singers’ comfort. This highlights the tension between the original architectural design of the cathedral and its modern religious and cultural usages. However, the regular occupants have developed a deep familiarity with these constraints during their ritual and musical practices, adjusting to the acoustics in a unique way. Such a tradition of adaptation must be considered as a part of cultural practice, not to be overlooked during the reconstruction.

BehaviorDEPOT is a simple, flexible tool for automated behavioral detection based on markerless pose tracking.

Quantitative descriptions of animal behavior are essential to study the neural substrates of cognitive and emotional processes. Analyses of naturalistic behaviors are often performed by hand or with expensive, inflexible commercial software. Recently, machine learning methods for markerless pose estimation enabled automated tracking of freely moving animals, including in labs with limited coding expertise. However, classifying specific behaviors based on pose data requires additional computational analyses and remains a significant challenge for many groups. We developed BehaviorDEPOT (DEcoding behavior based on POsitional Tracking), a simple, flexible software program that can detect behavior from video timeseries and can analyze the results of experimental assays. BehaviorDEPOT calculates kinematic and postural statistics from keypoint tracking data and creates heuristics that reliably detect behaviors. It requires no programming experience and is applicable to a wide range of behaviors and experimental designs. We provide several hard-coded heuristics. Our freezing detection heuristic achieves above 90% accuracy in videos of mice and rats, including those wearing tethered head-mounts. BehaviorDEPOT also helps researchers develop their own heuristics and incorporate them into the software's graphical interface. Behavioral data is stored framewise for easy alignment with neural data. We demonstrate the immediate utility and flexibility of BehaviorDEPOT using popular assays including fear conditioning, decision-making in a T-maze, open field, elevated plus maze, and novel object exploration.

Interaksi Demokratis Dalam Pembelajaran Eksploratif Fenomena Perubahan Suhu Udara dan Suhu Tanah

The purpose of this study is to explore the concept and scientific process of the phenomenon of changes in air temperature and soil temperature in vegetation land, open land, and asphalt roads. This study uses a qualitative and quantitative approach. The exploratory research used by the research team is themodel Higher Orther Thinking Learning in Democratic Interactionwhich (HOTL-DI) Type A emphasizes interactive components, individualistic high-level learning processes and democratic interactions as a process of sharing and cooperation between individuals in groups. The first stage of object exploration (changes in air temperature and soil temperature in vegetation land, open land, and asphalt roads), concepts and scientific processes is carried out by the research team under the guidance of the thesis supervisor. The second stage is exploratory research on fourth semester students majoring in physics education for the 2021 academic year. The stage of exploring physics objects, concepts and processes in groups as democratic interactions. Democratic indicators, formulated by researchers based on the condition of group interaction when exploring objects and discussing in group report preparation. Students experience difficulties at the beginning of exploration activities because they lack experience in exploring physical concepts and processes about natural phenomena. Democratic behavior and exploration activities seem to be getting better over time, so this learning can realize learning activities to explore objects, concepts and science processes in democratic interaction learning well.

Two distinct ways to form long-term object recognition memory during sleep and wakefulness

Memory consolidation is promoted by sleep. However, there is also evidence for consolidation into long-term memory during wakefulness via processes that preferentially affect nonhippocampal representations. We compared, in rats, the effects of 2-h postencoding periods of sleep and wakefulness on the formation of long-term memory for objects and their associated environmental contexts. We employed a novel-object recognition (NOR) task, using object exploration and exploratory rearing as behavioral indicators of these memories. Remote recall testing (after 1 wk) confirmed significant long-term NOR memory under both conditions, with NOR memory after sleep predicted by the occurrence of EEG spindle-slow oscillation coupling. Rats in the sleep group decreased their exploratory rearing at recall testing, revealing successful recall of the environmental context. By contrast, rats that stayed awake after encoding showed equally high levels of rearing upon remote testing as during encoding, indicating that context memory was lost. Disruption of hippocampal function during the postencoding interval (by muscimol administration) suppressed long-term NOR memory together with context memory formation when animals slept, but enhanced NOR memory when they were awake during this interval. Testing remote recall in a context different from that during encoding impaired NOR memory in the sleep condition, while exploratory rearing was increased. By contrast, NOR memory in the wake rats was preserved and actually superior to that after sleep. Our findings indicate two distinct modes of long-term memory formation: Sleep consolidation is hippocampus dependent and implicates event-context binding, whereas wake consolidation is impaired by hippocampal activation and strengthens context-independent representations.

Object recognition tasks in rats: Does sex matter?

Novelty recognition tasks based on object exploration are frequently used for the evaluation of cognitive abilities and investigation of neurobiological and molecular aspects of memory in rodents. This is an interesting approach because variations of the object recognition tasks focus on different aspects of the memory events such as novelty, location, context, and combinations of these elements. Nevertheless, as in most animal neuroscience research, female subjects are underrepresented in object recognition studies. When studies include females, the particularities of this sex are not always considered. For example, appropriate controls for manipulations conducted exclusively in females (such as estrous cycle verification) are not included. In addition, interpretation of data is often based on standardizations conducted with male subjects. Despite that, females are frequently reported as deficient and unable to adequately perform some memory tests. Thus, our study aims to review studies that describe similarities and differences between male and female performances in the different variations of object recognition tasks. In summary, although females are commonly described with deficits and the articles emphasize sex differences, most published data reveal similar performances when sexes are compared.