RESUMEN
An animal's umwelt, comprising its perception of the sensory environment, which is inherently subjective, can change across the lifespan in accordance with major life events. In mammals, the onset of motherhood, in particular, is associated with a neural and sensory plasticity that alters a mother's detection and use of sensory information such as infant-related sensory stimuli. Although the literature surrounding mammalian mothers is well established, very few studies have addressed the effects of parenthood on sensory plasticity in mammalian fathers. In this review, we summarize the major findings on the effects of parenthood on behavioural and neural responses to sensory stimuli from pups in rodent mothers, with a focus on the olfactory, auditory, and somatosensory systems, as well as multisensory integration. We also review the available literature on sensory plasticity in rodent fathers. Finally, we discuss the importance of sensory plasticity for effective parental care, hormonal modulation of plasticity, and an exploration of temporal, ecological, and life-history considerations of sensory plasticity associated with parenthood. The changes in processing and/or perception of sensory stimuli associated with the onset of parental care may have both transient and long-lasting effects on parental behaviour and cognition in both mothers and fathers; as such, several promising areas of study, such as on the molecular/genetic, neurochemical, and experiential underpinnings of parenthood-related sensory plasticity, as well as determinants of interspecific variation, remain potential avenues for further exploration.
Asunto(s)
Conducta Materna , Conducta Paterna , Percepción , Roedores , Sensación , Roedores/psicología , Animales , Vías Nerviosas/fisiología , Plasticidad NeuronalRESUMEN
Social rewards are fundamental to survival and overall health. Several studies suggest that adequate social stimuli during early life are critical for developing appropriate socioemotional and cognitive skills, whereas adverse social experiences negatively affect the proper development of brain and behavior, by increasing the susceptibility to develop neuropsychiatric conditions. Therefore, a better understanding of the neural mechanisms underlying social interactions, and their rewarding components in particular, is an important challenge of current neuroscience research. In this context, preclinical research has a crucial role: Animal models allow to investigate the neurobiological aspects of social reward in order to shed light on possible neurochemical alterations causing aberrant social reward processing in neuropsychiatric diseases, and they allow to test the validity and safety of innovative therapeutic strategies. Here, we discuss preclinical research that has investigated the rewarding properties of two forms of social interaction that occur in different phases of the lifespan of mammals, that is, mother-infant interaction and social interactions with peers, by focusing on the main neurotransmitter systems mediating their rewarding components. Together, the research performed so far helped to elucidate the mechanisms of social reward and its psychobiological components throughout development, thus increasing our understanding of the neurobiological substrates sustaining social functioning in health conditions and social dysfunction in major psychiatric disorders.
Asunto(s)
Neuroquímica , Recompensa , Roedores/psicología , Conducta Social , Envejecimiento/psicología , Animales , Humanos , Ratones , Ratas , Interacción SocialRESUMEN
Animal behavior is highly structured. Yet, structured behavioral patterns-or "statistical ethograms"-are not immediately apparent from the full spatiotemporal data that behavioral scientists usually collect. Here, we introduce a framework to quantitatively characterize rodent behavior during spatial (e.g., maze) navigation, in terms of movement building blocks or motor primitives. The hypothesis that we pursue is that rodent behavior is characterized by a small number of motor primitives, which are combined over time to produce open-ended movements. We assume motor primitives to be organized in terms of two sparsity principles: each movement is controlled using a limited subset of motor primitives (sparse superposition) and each primitive is active only for time-limited, time-contiguous portions of movements (sparse activity). We formalize this hypothesis using a sparse dictionary learning method, which we use to extract motor primitives from rodent position and velocity data collected during spatial navigation, and successively to reconstruct past trajectories and predict novel ones. Three main results validate our approach. First, rodent behavioral trajectories are robustly reconstructed from incomplete data, performing better than approaches based on standard dimensionality reduction methods, such as principal component analysis, or single sparsity. Second, the motor primitives extracted during one experimental session generalize and afford the accurate reconstruction of rodent behavior across successive experimental sessions in the same or in modified mazes. Third, in our approach the number of motor primitives associated with each maze correlates with independent measures of maze complexity, hence showing that our formalism is sensitive to essential aspects of task structure. The framework introduced here can be used by behavioral scientists and neuroscientists as an aid for behavioral and neural data analysis. Indeed, the extracted motor primitives enable the quantitative characterization of the complexity and similarity between different mazes and behavioral patterns across multiple trials (i.e., habit formation). We provide example uses of this computational framework, showing how it can be used to identify behavioural effects of maze complexity, analyze stereotyped behavior, classify behavioral choices and predict place and grid cell displacement in novel environments.
Asunto(s)
Conducta Animal/fisiología , Roedores/fisiología , Roedores/psicología , Navegación Espacial/fisiología , Animales , Aprendizaje por Laberinto , Actividad Motora/fisiología , Movimiento/fisiología , Conducta Estereotipada/fisiologíaRESUMEN
The rise in the number of users and institutions utilizing the rodent touchscreen technology for cognitive testing over the past decade has prompted the need for knowledge mobilization and community building. To address the needs of the growing touchscreen community, the first international touchscreen symposium was hosted at Western University. Attendees from around the world attended talks from expert neuroscientists using touchscreens to examine a vast array of questions regarding cognition and the nervous system. In addition to the symposium, a subset of attendees was invited to partake in a hands-on training course where they received touchscreen training covering both hardware and software components. Beyond the two touchscreen events, virtual platforms have been developed to further support touchscreen users: (a) Mousebytes.ca, which includes a data repository of rodent touchscreen tasks, and (b) Touchscreencognition.org, an online community with numerous training and community resources, perhaps most notably a forum where members can ask and answer questions. The advantages of the rodent touchscreen technology for cognitive neuroscience research has allowed neuroscientists from diverse backgrounds to test specific cognitive processes using well-validated and standardized apparatus, contributing to its rise in popularity and its relevance to modern neuroscience research. The commitment of the touchscreen community to data, task development and information sharing not only ensures an expansive future of the use of rodent touchscreen technology but additionally, quality research that will increase translation from preclinical studies to clinical successes.
Asunto(s)
Investigación Conductal/métodos , Cognición , Roedores/fisiología , Interfaz Usuario-Computador , Animales , Investigación Conductal/instrumentación , Investigación Conductal/estadística & datos numéricos , Congresos como Asunto , Roedores/genética , Roedores/psicología , TactoRESUMEN
Categorization is a fundamental cognitive function that organizes our experiences into meaningful "chunks." This category knowledge can then be generalized to novel stimuli and situations. Multiple clinical populations, including people with Parkinson's disease, amnesia, autism, ADHD and schizophrenia, have impairments in the acquisition and use of categories. Although rodent research is well suited for examining the neural mechanisms underlying cognitive functions, many rodent cognitive tasks have limited translational value. To bridge this gap, we use touchscreens to permit greater flexibility in stimulus presentation and task design, track key dependent measures, and minimize experimenter involvement. Touchscreens offer a valuable tool for creating rodent cognitive tasks that are directly comparable to tasks used with humans. Touchscreen tasks are also readily used with cutting-edge neuroscientific methods that are difficult to do in humans such as optogenetics, chemogenetics, neurophysiology and calcium imaging (using miniscopes). In this review, we show advantages of touchscreen-based tasks for studying category learning in rats. We also address multiple factors for consideration when designing category learning tasks, including the limitations of the rodent visual system, experimental design, and analysis strategies.
Asunto(s)
Investigación Conductal/métodos , Generalización Psicológica , Roedores/fisiología , Interfaz Usuario-Computador , Animales , Investigación Conductal/instrumentación , Roedores/psicologíaRESUMEN
Human activities are changing landscape structure and function globally, affecting wildlife space use, and ultimately increasing human-wildlife conflicts and zoonotic disease spread. Capybaras (Hydrochoerus hydrochaeris) are linked to conflicts in human-modified landscapes (e.g. crop damage, vehicle collision), as well as the spread and amplification of Brazilian spotted fever (BSF), the most human-lethal tick-borne disease in the world. Even though it is essential to understand the link between capybaras, ticks and BSF, many knowledge gaps still exist regarding the effects of human disturbance in capybara space use. Here, we analyzed diurnal and nocturnal habitat selection strategies of capybaras across natural and human-modified landscapes using resource selection functions (RSF). Selection for forested habitats was higher across human-modified landscapes, mainly during day- periods, when compared to natural landscapes. Across natural landscapes, capybaras avoided forests during both day- and night periods. Water was consistently selected across both landscapes, during day- and nighttime. Distance to water was also the most important variable in predicting capybara habitat selection across natural landscapes. Capybaras showed slightly higher preferences for areas near grasses/shrubs across natural landscapes, and distance to grasses/shrubs was the most important variable in predicting capybara habitat selection across human-modified landscapes. Our results demonstrate human-driven variation in habitat selection strategies by capybaras. This behavioral adjustment across human-modified landscapes may be related to increases in A. sculptum density, ultimately affecting BSF.
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Ecosistema , Roedores/psicología , Animales , Animales Salvajes , Brasil , Ambiente , Pradera , Interacciones Huésped-Parásitos/fisiología , Humanos , Fiebre Maculosa de las Montañas Rocosas/epidemiología , Garrapatas , Agua , ZoonosisRESUMEN
Environmental enrichment is a widely used experimental manipulation that consistently shows measurable effects on rodent behaviour across the lifespan. This scoping review assesses and thematically summarizes the literature of the past decade concerning the effects of environmental enrichment applied during sensitive developmental periods in rodent mothers and offspring. Maternal behaviours as well as maternal and offspring anxiety- and depressive-like behaviours are considered. Relevant terms were searched across five databases (Embase, MEDLINE, PsycINFO, PubMed, Web of Science) and articles were screened with inclusion and exclusion criteria. The remaining articles were thematically analysed. Our results suggest that a greater number of articles reviewed the impacts of environmental enrichment on offspring anxiety-like behaviour (n = 23) rather than on depressive-like behaviour (n = 11) or maternal caregiving behaviour (n = 12). Maternal anxiety- (n = 4) or depressive-like (n = 2) behaviours are not often evaluated for in enrichment studies. The main behavioural tests of anxiety that were reviewed include the elevated plus-maze, the open field test, and the light-dark box whereas those for depression included the forced swim test and the sucrose preference test. Our results yielded mixed findings and significant variation in behavioural responses across all tests. In mothers, trends of increased maternal care behaviours and decreased maternal depressive-like behaviours in enriched mothers were appreciated. Enrichment during the gestational period was identified as pivotal to creating behavioural change in mother subjects. In enriched offspring rodents, a trend towards decreased anxiety-like behaviours was observed most often. Potential confounds inherent in enrichment paradigms and relevant theories of enrichment and their relation to rodent behavioural tests are discussed.
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Ansiedad/prevención & control , Depresión/prevención & control , Vivienda para Animales , Conducta Materna/fisiología , Roedores/psicología , Conducta Social , Interacción Social , Animales , Conducta Animal , Conducta Exploratoria/fisiología , Femenino , Edad Gestacional , Masculino , Estimulación Física/métodosRESUMEN
Environmental enrichment and physical exercise have many well-established health benefits. Although these environmental manipulations are known to delay symptom onset and progression in a variety of neurological and psychiatric conditions, the mechanisms underlying these effects remain poorly understood. A notable candidate molecular mechanism is that of microRNA, a family of small noncoding RNAs that are important regulators of gene expression. Research investigating the many diverse roles of microRNAs has greatly expanded over the past decade, with several promising preclinical and clinical studies highlighting the role of dysregulated microRNA expression (in the brain, blood and other peripheral systems) in understanding the aetiology of disease. Altered microRNA levels have also been described following environmental interventions such as exercise and environmental enrichment in non-clinical populations and wild-type animals, as well as in some brain disorders and associated preclinical models. Recent studies exploring the effects of stimulating environments on microRNA levels in the brain have revealed an array of changes that are likely to have important downstream effects on gene expression, and thus may regulate a variety of cellular processes. Here we review literature that explores the differential expression of microRNAs in rodents following environmental enrichment and exercise, in both healthy control animals and preclinical models of relevance to neurological and psychiatric disorders.
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Encéfalo/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Condicionamiento Físico Animal , Roedores/psicología , Conducta Social , Interacción Social , Animales , Encefalopatías/genética , Encefalopatías/metabolismo , Ejercicio Físico , Expresión Génica , Humanos , Trastornos Mentales/genética , Trastornos Mentales/metabolismoRESUMEN
Altered disturbance regimes, increasing atmospheric CO2, and other processes have increased woody cover and homogenized vegetation in savannas across the planet. African savannas with extensive versus minimal woody cover often have vastly different animal communities. However, we lack a clear mechanistic understanding of why animal communities are changing with vegetation structure. Our goal for this study was to understand how vegetation structure in an African savanna shaped the perceived predation risk of small mammals, hence affecting their activity. Using a reciprocal measure of standard giving-up-densities, amount of food eaten, we found sharp declines in rodents' perceived predation risk and increased rodent activity underneath shrub cover. This response was consistent across species; however, species showed subtle differences in their responses to grassy vegetation. Our findings suggest that areas of minimal or extensive shrub cover (shrub encroachment) may be homogenizing rodents' perceptions of predation risk and thus shaping their use of space.
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Poaceae/fisiología , Conducta Predatoria/fisiología , Roedores/fisiología , Animales , Esuatini , Cadena Alimentaria , Pradera , Dinámica Poblacional , Roedores/psicología , Árboles/fisiologíaRESUMEN
OBJECTIVES: This is the first study of the sonic and ultrasonic vocalization in a Dipodidae rodent. For the small-sized quadrupedal northern birch mouse Sicista betulina, phylogenetically related to the bipedal jerboas (Dipodidae), we report null results for ultrasonic vocalization and investigate the acoustic cues to individual identity, sex and body size in the discomfort-related high-frequency tonal sonic calls. RESULTS: We used a parallel audio recording in the sonic and ultrasonic ranges during weighting adult northern birch mice before the scheduled hibernation in captivity. The sonic (audible) high-frequency tonal calls (ranging from 6.21 to 9.86 kHz) were presented in all individuals (7 males and 4 females). The ultrasonic calls lacked in the recordings. Two-way nested ANOVA revealed the effects of caller individual identity on all 10 measured acoustic variables and the effects of sex on four out of 10 measured acoustic variables. Discriminant function analyses with 10 acoustic variables included in the analysis showed 85.5% correct assignment of calls to individual and 79.7% correct assignment of calls to sex; both values significantly exceeded the random values (23.1% and 54.3%, respectively) calculated with randomization procedure. Body mass did not differ between sexes and did not correlate significantly with the acoustic variables.
Asunto(s)
Tamaño Corporal/fisiología , Roedores/fisiología , Conducta Sexual Animal/fisiología , Vocalización Animal/fisiología , Acústica/instrumentación , Animales , Análisis Discriminante , Femenino , Manejo Psicológico , Masculino , Roedores/psicología , Espectrografía del Sonido , Ultrasonido/instrumentaciónRESUMEN
Excessive preference for risky over safe options is a hallmark of several psychiatric disorders. Here we describe a behavioral task that models such risky decision making in rats. In this task, rats are given choices between small, safe rewards and large rewards accompanied by risk of footshock punishment. The risk of punishment changes within a test session, allowing quantification of decision making at different levels of risk. Importantly, this task can yield a wide degree of reliable individual variability, allowing the characterization of rats as "risk-taking" or "risk-averse." The task has been demonstrated to be effective for testing the effects of pharmacological agents and neurobiological manipulations, and the individual variability (which mimics the human population) allows assessment of behavioral and neurobiological distinctions among subjects based on their risk-taking profile.
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Conducta Animal , Toma de Decisiones , Técnicas de Apoyo para la Decisión , Modelos Teóricos , Roedores/psicología , Animales , Interpretación Estadística de Datos , Modelos Animales de Enfermedad , Trastornos Mentales/etiología , Trastornos Mentales/psicología , RatasRESUMEN
Insomnia involves disruption of sleep initiation, maintenance and/or overall quality, and may interfere with cognition. Here, we evaluated memory impairment produced by rodent mild (acute) insomnia models. Insomnia models consisted of either single or repeated exposure to cages previously occupied (dirtied) by an unfamiliar rat for 5-7â days. Rats were trained in the Morris water maze to remember the platform location (acquisition), and were then exposed to: (a) 6â hr of undisturbed baseline; (b) dirty cage change-induced insomnia (animal placed into a cage dirtied by another rat for 6â hr); or (c) double-dirty cage change-induced insomnia (animal placed into a cage dirtied by another rat for 3â hr, and then another dirty cage 3â hr later). The animal's memory for the platform location was then evaluated in a probe trial. Double-dirty cage change-induced insomnia significantly disrupted sleep, although the effects of dirty cage change-induced insomnia were overall not significant. In the fourth hour of double-dirty cage change-induced insomnia (following the second cage change), sleep episode number and duration alterations indicated sleep fragmentation. Furthermore, power spectral analysis revealed diminished wake and, to a lesser extent, rapid eye movement theta power (indicated by trend difference) in the last 3â hr of exposure. Significant deficits were noted for measures of water maze performance following double-dirty cage change-induced insomnia, indicating impaired memory. In summary, one variant of the rodent insomnia model, double-dirty cage change-induced insomnia, disrupted sleep and attenuated memory consolidation, indicating this paradigm may be useful to evaluate the effects of hypnotics on memory consolidation.
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Consolidación de la Memoria/fisiología , Roedores/psicología , Trastornos del Inicio y del Mantenimiento del Sueño/etiología , Animales , Masculino , Ratas , Ratas Sprague-Dawley , Sueño/efectos de los fármacosRESUMEN
A key challenge for animals is recognising locations and navigating between them. These capacities are varied: we can remember where our car is parked at the mall, rats are able to remember where their nest location is while foraging for food morsels, and bats are able to fly directly to a favourite fruit tree 20 kilometers from their home cave. These spatial abilities, whether commonplace or remarkable, raise fundamental questions. First, how do animals find their way? Second, how does the brain represent the outside world? In this Primer, we will address both questions from the perspective of rodent cognition and neuroscience.
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Cognición , Roedores/psicología , Navegación Espacial , Animales , Roedores/fisiologíaRESUMEN
Desert communities world-wide are used as natural laboratories for the study of convergent evolution, yet inferences drawn from such studies are necessarily indirect. Here, we brought desert organisms together (rodents and vipers) from two deserts (Mojave and Negev). Both predators and prey in the Mojave have adaptations that give them competitive advantage compared to their middle-eastern counterparts. Heteromyid rodents of the Mojave, kangaroo rats and pocket mice, have fur-lined cheek pouches that allow them to carry larger loads of seeds under predation risk compared to gerbilline rodents of the Negev Deserts. Sidewinder rattlesnakes have heat-sensing pits, allowing them to hunt better on moonless nights when their Negev sidewinding counterpart, the Saharan horned vipers, are visually impaired. In behavioral-assays, we used giving-up density (GUD) to gauge how each species of rodent perceived risk posed by known and novel snakes. We repeated this for the same set of rodents at first encounter and again two months later following intensive "natural" exposure to both snake species. Pre-exposure, all rodents identified their evolutionarily familiar snake as a greater risk than the novel one. However, post-exposure all identified the heat-sensing sidewinder rattlesnake as a greater risk. The heteromyids were more likely to avoid encounters with, and discern the behavioral difference among, snakes than their gerbilline counterparts.
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Evolución Biológica , Conducta Predatoria , Roedores/clasificación , Roedores/psicología , Viperidae/fisiología , Animales , MasculinoRESUMEN
OBJETIVO: Realizar una revisión sistemática para conocer el efecto del ejercicio físico sobre el sistema serotoninérgico y la conducta en roedores. Estrategia de búsqueda: Se realizó una revisión bibliográfica en marzo de 2017 en las bases de datos y buscadores: Pubmed, Medline, Cinahl, Sport Discus, Scopus, Web of Science, Cochrane library y Plos One. Selección de estudios: Se aplicaron los criterios de inclusión (ensayos publicados entre enero de 2012 y febrero 2017) y exclusión (trabajos realizados en humanos, estudios duplicados y que no se ajustases al tema de estudio), obteniéndose un total de 12 artículos. Síntesis de resultados: El ejercicio disminuye la conducta ansiosa. En cuanto al neurotransmisor estudiado existen diferentes resultados. CONCLUSIONES: El ejercicio físico ejerce cambios a nivel conductual y cerebral. El efecto sobre neurotransmisor 5-HT depende de la región o sistema cerebral estudiados. Aumenta los niveles de 5HT1a provocando un efecto ansiolítico y la resistencia a la acción ansiogénica del 5HT2c
OBJECTIVE: Perform a systematic review to know the effect of physical exercise on the serotoninergic system and behavior in rodents. Search strategy: In March 2017 the following databases and search engines were used: Pubmed, Medline, Cinahl, Sport Discus, Scopus, Web of Science, Cochrane library and Plos One. Selection of studies: After applying the inclusion (published trials between January 2012 and February 2017) and exclusion criteria (human work, duplicate studies and those not adjusted to the subject of study) 12 articles were analysed. Synthesis of results: exercise decreases anxious behavior. As for the neurotransmitter studied, there are different results. CONCLUSIONS: physical exercise exerts behavioral and cerebral changes. The effect on 5-HT neurotransmitter depends on the region or brain system studied. It increases 5HT1a levels provoking an anxiolytic effect and the resistance to the anxiogenic action of 5HT2c
Asunto(s)
Animales , Ejercicio Físico/psicología , Serotoninérgicos/metabolismo , Trastornos de Ansiedad , Conducta Animal/fisiología , Roedores/psicología , SerotoninaRESUMEN
Behavioral studies using animal models have widely contributed to advancing our understanding of the neuroregulatory mechanisms of human cognitive states and disorders. A variety of behavioral tests and theoretical models have been developed that provide a standardized toolbox of behavioral test paradigms available to researchers, and thus allow rapid progress in studies of the molecular-genetic bases of behavior relevant to neurocognitive diseases. However, a growing effort to utilize standardized paradigms has overlooked the diverse behavioral characteristics of test rodents expressed in standardized test situations. This review describes two popular test paradigms for cognitive assessment in rodents: social recognition and fear conditioning tasks. An extensive assessment of observed behavior during testing indicates a need to further elucidate the sequential strategic processes employed by test animals in conjunction with the use of standardized test settings and dependent variables. The present study calls specific attention to the considerable but improvable problem of the appropriateness and applicability of these standardized test paradigms; it thereby unravels the essential contribution of multi-behavioral assessment to further advancing neuroscience research using rodent behavioral models.
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Condicionamiento Clásico , Miedo/psicología , Reconocimiento en Psicología , Roedores/psicología , Conducta Social , Animales , Reacción de Prevención , Reacción Cataléptica de Congelación , Memoria , Ratones , Modelos Animales , RatasRESUMEN
Callous-unemotional traits - the insensitivity to other's welfare and well-being - are characterized by a lack of empathy. They are characteristic of psychopathy and can be found in other anti-social disorders, such as conduct disorder. Because of the increasing prevalence of anti-social disorders and the rising societal costs of violence and aggression, it is of great importance to elucidate the psychological and physiological mechanisms underlying callousness in the search for pharmacological treatments. One promising avenue is to create a relevant animal model to explore the neural bases of callousness. Here, we review recent advances in rodent models of pro-social choice that could be applied to probe the absence of pro-sociality as a proxy of callous behavior, and provide future directions for the exploration of the neural substrates of callousness.
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Modelos Animales de Enfermedad , Empatía , Animales , Trastorno de Personalidad Antisocial/psicología , Conducta de Elección , Roedores/psicología , Conducta SocialRESUMEN
The translational value of preclinical research was recently enhanced by abnormal aggression models, which focus on deviant behaviors induced by the exposure of rodents to etiological factors of aggression-related psychopathologies. Prompted by similar trials in other psychiatric disorders, here we investigate models of abnormal aggression from the perspective of DSM5 criteria. After proposing principles based on which analogies can be established between psychopathology symptoms and rodent behavioral dysfunctions, we show that rodents submitted to abnormal aggression models fulfill basic criteria of aggression-related psychopathologies; moreover, some models can be considered specific to particular disorders e.g. conduct disorder. We also show that abnormal and species-typical aggressions differ in terms of both brain mechanisms and pharmacological responsiveness, which mimics differences observed in psychiatric disorders. We conclude that evaluating abnormal aggression models from a DSM5 perspective is not only possible but also worthwhile, and such models may contribute to the development of novel treatment strategies not only for aggression as a symptom but also for specific aggression-related disorders or multi-symptom clusters at least.
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Agresión/efectos de los fármacos , Agresión/psicología , Trastorno de la Conducta/psicología , Psicotrópicos/farmacología , Roedores/psicología , Animales , Encéfalo/efectos de los fármacos , Modelos Animales de EnfermedadRESUMEN
Empathy is a psychological construct that allows individuals to understand and share the emotions of others. The ability to share emotional states relies on basic social mechanisms, such as mimicry and emotional contagion, which are considered building blocks for empathy. Mimicking another's emotional or physical state is essential for successful social interactions and is found in a number of animal species. For the current review we focus on emotional state sharing in rodents, a core feature of empathy that is often measured using pain and fear as proxies; we also discuss prosociality in rodents. The evidence for empathy in rodents shows that rats and mice consistently imitate arousal states and behaviors of conspecifics and will even sacrifice personal gain to relieve the distress of a conspecific. These behaviors support basic processes that are crucial for the survival of individual animals and give us insight into the neural mechanisms that govern empathy-related behaviors.
Asunto(s)
Empatía , Roedores/psicología , Animales , Emociones , Miedo , Dolor/psicología , Conducta SocialRESUMEN
Pathological aggression, frequently observed in psychiatric patients and criminal subjects, poses a major burden on the health care and criminal justice system, necessitating better aetiological models to inform targets for prevention and intervention. Emerging evidence suggests that adverse experiences during development can cause long-lasting brain alterations associated with maladaptive behaviors, such as aggression. The present review discusses, mainly based on studies in rodents, whether disruption of the mesocorticolimbic dopamine system through chronic stress-exposure during adolescence predisposes to adult aggression. Our findings suggest that chronic stress in adolescence induces prefrontal cortex (PFC) hyperdopaminergia and ultimately leads to blunted prefrontal dopamine transmission in adulthood. This, in turn, disrupts the ability of the PFC to guide adaptive, long-term focused action selection by regulating mesolimbic dopamine signaling. We propose that, especially during the dynamic and transitional period of adolescence, exposure to chronic stress could lead to excessive adaptive change, which may result in an increased vulnerability to maladaptive aggression in adulthood. We discuss how these findings in rodents may translate to humans.