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1.
Elife ; 102021 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-34661526

RESUMO

Navigation through space involves learning and representing relationships between past, current, and future locations. In mammals, this might rely on the hippocampal theta phase code, where in each cycle of the theta oscillation, spatial representations provided by neuronal sequences start behind the animal's true location and then sweep forward. However, the exact relationship between theta phase, represented position and true location remains unclear and even paradoxical. Here, we formalize previous notions of 'spatial' or 'temporal' theta sweeps that have appeared in the literature. We analyze single-cell and population variables in unit recordings from rat CA1 place cells and compare them to model simulations based on each of these schemes. We show that neither spatial nor temporal sweeps quantitatively accounts for how all relevant variables change with running speed. To reconcile these schemes with our observations, we introduce 'behavior-dependent' sweeps, in which theta sweep length and place field properties, such as size and phase precession, vary across the environment depending on the running speed characteristic of each location. These behavior-dependent spatial maps provide a structured heterogeneity that is essential for understanding the hippocampal code.


Assuntos
Neurônios/fisiologia , Comportamento Espacial/fisiologia , Ritmo Teta/fisiologia , Animais , Aprendizagem/fisiologia , Masculino , Células de Lugar/fisiologia , Ratos , Ratos Long-Evans
2.
Nat Neurosci ; 24(11): 1614-1627, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34608335

RESUMO

Brain oscillations have been hypothesized to support cognitive function by coordinating spike timing within and across brain regions, yet it is often not known when timing is either critical for neural computations or an epiphenomenon. The entorhinal cortex and hippocampus are necessary for learning and memory and exhibit prominent theta oscillations (6-9 Hz), which are controlled by pacemaker cells in the medial septal area. Here we show that entorhinal and hippocampal neuronal activity patterns were strongly entrained by rhythmic optical stimulation of parvalbumin-positive medial septal area neurons in mice. Despite strong entrainment, memory impairments in a spatial working memory task were not observed with pacing frequencies at or below the endogenous theta frequency and only emerged at frequencies ≥10 Hz, and specifically when pacing was targeted to maze segments where encoding occurs. Neural computations during the encoding phase were therefore selectively disrupted by perturbations of the timing of neuronal firing patterns.


Assuntos
Córtex Entorrinal/fisiologia , Hipocampo/fisiologia , Memória/fisiologia , Comportamento Espacial/fisiologia , Ritmo Teta/fisiologia , Animais , Córtex Entorrinal/química , Hipocampo/química , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Transgênicos , Optogenética/métodos , Fatores de Tempo
3.
Nat Neurosci ; 24(11): 1574-1585, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34663956

RESUMO

Spatial memories that can last a lifetime are thought to be encoded during 'online' periods of exploration and subsequently consolidated into stable cognitive maps through their 'offline' reactivation. However, the mechanisms and computational principles by which offline reactivation stabilize long-lasting spatial representations remain poorly understood. Here, we employed simultaneous fast calcium imaging and electrophysiology to track hippocampal place cells over 2 weeks of online spatial reward learning behavior and offline resting. We describe that recruitment to persistent network-level offline reactivation of spatial experiences in mice predicts the future representational stability of place cells days in advance of their online reinstatement. Moreover, while representations of reward-adjacent locations are generally more stable across days, offline-reactivation-related stability is, conversely, most prominent for reward-distal locations. Thus, while occurring on the tens of milliseconds timescale, offline reactivation is uniquely associated with the stability of multiday representations that counterbalance the overall reward-adjacency bias, thereby predicting the stabilization of cognitive maps that comprehensively reflect entire underlying spatial contexts. These findings suggest that post-learning offline-related memory consolidation plays a complimentary and computationally distinct role in learning compared to online encoding.


Assuntos
Mapeamento Encefálico/métodos , Cognição/fisiologia , Hipocampo/fisiologia , Consolidação da Memória/fisiologia , Células de Lugar/fisiologia , Comportamento Espacial/fisiologia , Animais , Previsões , Hipocampo/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
4.
PLoS One ; 16(9): e0256211, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34499667

RESUMO

Previous studies have suggested that virtual reality (VR) can elicit emotions in different visual modes using 2D or 3D headsets. However, the effects on emotional arousal by using these two visual modes have not been comprehensively investigated, and the underlying neural mechanisms are not yet clear. This paper presents a cognitive psychological experiment that was conducted to analyze how these two visual modes impact emotional arousal. Forty volunteers were recruited and were randomly assigned to two groups. They were asked to watch a series of positive, neutral and negative short VR videos in 2D and 3D. Multichannel electroencephalograms (EEG) and skin conductance responses (SCR) were recorded simultaneously during their participation. The results indicated that emotional stimulation was more intense in the 3D environment due to the improved perception of the environment; greater emotional arousal was generated; and higher beta (21-30 Hz) EEG power was identified in 3D than in 2D. We also found that both hemispheres were involved in stereo vision processing and that brain lateralization existed in the processing.


Assuntos
Nível de Alerta , Encéfalo/fisiologia , Cognição , Emoções/fisiologia , Comportamento Espacial/fisiologia , Realidade Virtual , Percepção Visual/fisiologia , Adulto , Percepção de Profundidade , Feminino , Humanos , Masculino , Estimulação Luminosa , Adulto Jovem
5.
Nat Commun ; 12(1): 5286, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489431

RESUMO

Vomeronasal information is critical in mice for territorial behavior. Consequently, learning the territorial spatial structure should incorporate the vomeronasal signals indicating individual identity into the hippocampal cognitive map. In this work we show in mice that navigating a virtual environment induces synchronic activity, with causality in both directionalities, between the vomeronasal amygdala and the dorsal CA1 of the hippocampus in the theta frequency range. The detection of urine stimuli induces synaptic plasticity in the vomeronasal pathway and the dorsal hippocampus, even in animals with experimentally induced anosmia. In the dorsal hippocampus, this plasticity is associated with the overexpression of pAKT and pGSK3ß. An amygdalo-entorhino-hippocampal circuit likely underlies this effect of pheromonal information on hippocampal learning. This circuit likely constitutes the neural substrate of territorial behavior in mice, and it allows the integration of social and spatial information.


Assuntos
Tonsila do Cerebelo/fisiologia , Região CA1 Hipocampal/fisiologia , Glicogênio Sintase Quinase 3 beta/genética , Percepção Olfatória/fisiologia , Proteínas Proto-Oncogênicas c-akt/genética , Comportamento Espacial/fisiologia , Órgão Vomeronasal/fisiologia , Tonsila do Cerebelo/citologia , Animais , Anosmia/genética , Anosmia/metabolismo , Anosmia/fisiopatologia , Comportamento Animal , Região CA1 Hipocampal/citologia , Feminino , Regulação da Expressão Gênica , Glicogênio Sintase Quinase 3 beta/metabolismo , Aprendizagem/fisiologia , Masculino , Camundongos , Rede Nervosa/citologia , Rede Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Neurônios/citologia , Neurônios/metabolismo , Feromônios/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Percepção Social , Percepção Espacial/fisiologia , Ritmo Teta/fisiologia , Órgão Vomeronasal/citologia
6.
Neuron ; 109(18): 2967-2980.e11, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34363753

RESUMO

Neurons in the medial entorhinal cortex alter their firing properties in response to environmental changes. This flexibility in neural coding is hypothesized to support navigation and memory by dividing sensory experience into unique episodes. However, it is unknown how the entorhinal circuit as a whole transitions between different representations when sensory information is not delineated into discrete contexts. Here we describe rapid and reversible transitions between multiple spatial maps of an unchanging task and environment. These remapping events were synchronized across hundreds of neurons, differentially affected navigational cell types, and correlated with changes in running speed. Despite widespread changes in spatial coding, remapping comprised a translation along a single dimension in population-level activity space, enabling simple decoding strategies. These findings provoke reconsideration of how the medial entorhinal cortex dynamically represents space and suggest a remarkable capacity of cortical circuits to rapidly and substantially reorganize their neural representations.


Assuntos
Mapeamento Encefálico/métodos , Córtex Entorrinal/fisiologia , Rede Nervosa/fisiologia , Percepção Espacial/fisiologia , Comportamento Espacial/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL
7.
Sci Rep ; 11(1): 16217, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376774

RESUMO

Here, we provide unique photo documentation and observational evidence of rescue behaviour described for the first time in wild boar. Rescue behaviour represents an extreme form of prosocial behaviour that has so far only been demonstrated in a few species. It refers to a situation when one individual acts to help another individual that finds itself in a dangerous or stressful situation and it is considered by some authors as a complex form of empathy. We documented a case in which an adult female wild boar manipulated wooden logs securing the door mechanism of a cage trap and released two entrapped young wild boars. The whole rescue was fast and particular behaviours were complex and precisely targeted, suggesting profound prosocial tendencies and exceptional problem-solving capacities in wild boar. The rescue behaviour might have been motivated by empathy because the rescuer female exhibited piloerection, a sign of distress, indicating an empathetic emotional state matching or understanding the victims. We discuss this rescue behaviour in the light of possible underlying motivators, including empathy, learning and social facilitation.


Assuntos
Comportamento Animal/fisiologia , Restrição Física/métodos , Comportamento Social , Comportamento Espacial/fisiologia , Animais , Feminino , Suínos
8.
Nat Commun ; 12(1): 4473, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294703

RESUMO

Feedback in the brain is thought to convey contextual information that underlies our flexibility to perform different tasks. Empirical and computational work on the visual system suggests this is achieved by targeting task-relevant neuronal subpopulations. We combine two tasks, each resulting in selective modulation by feedback, to test whether the feedback reflected the combination of both selectivities. We used visual feature-discrimination specified at one of two possible locations and uncoupled the decision formation from motor plans to report it, while recording in macaque mid-level visual areas. Here we show that although the behavior is spatially selective, using only task-relevant information, modulation by decision-related feedback is spatially unselective. Population responses reveal similar stimulus-choice alignments irrespective of stimulus relevance. The results suggest a common mechanism across tasks, independent of the spatial selectivity these tasks demand. This may reflect biological constraints and facilitate generalization across tasks. Our findings also support a previously hypothesized link between feature-based attention and decision-related activity.


Assuntos
Córtex Visual/fisiologia , Animais , Atenção/fisiologia , Tomada de Decisões/fisiologia , Discriminação Psicológica , Retroalimentação Sensorial , Macaca mulatta/fisiologia , Masculino , Modelos Neurológicos , Estimulação Luminosa , Comportamento Espacial/fisiologia , Processamento Espacial/fisiologia , Percepção Visual/fisiologia
9.
J Neurosci ; 41(32): 6933-6945, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34210776

RESUMO

The orbitofrontal cortex (OFC) and hippocampus share striking cognitive and functional similarities. As a result, both structures have been proposed to encode "cognitive maps" that provide useful scaffolds for planning complex behaviors. However, while this function has been exemplified by spatial coding in neurons of hippocampal regions-particularly place and grid cells-spatial representations in the OFC have been investigated far less. Here we sought to address this by recording OFC neurons from male rats engaged in an open-field foraging task like that originally developed to characterize place fields in rodent hippocampal neurons. Single-unit activity was recorded as rats searched for food pellets scattered randomly throughout a large enclosure. In some sessions, particular flavors of food occurred more frequently in particular parts of the enclosure; in others, only a single flavor was used. OFC neurons showed spatially localized firing fields in both conditions, and representations changed between flavored and unflavored foraging periods in a manner reminiscent of remapping in the hippocampus. Compared with hippocampal recordings taken under similar behavioral conditions, OFC spatial representations were less temporally reliable, and there was no significant evidence of grid tuning in OFC neurons. These data confirm that OFC neurons show spatial firing fields in a large, two-dimensional environment in a manner similar to hippocampus. Consistent with the focus of the OFC on biological meaning and goals, spatial coding was weaker than in hippocampus and influenced by outcome identity.SIGNIFICANCE STATEMENT The orbitofrontal cortex (OFC) and hippocampus have both been proposed to encode "cognitive maps" that provide useful scaffolds for planning complex behaviors. This function is exemplified by place and grid cells identified in hippocampus, the activity of which maps spatial environments. The current study directly demonstrates very similar, though not identical, spatial representatives in OFC neurons, confirming that OFC-like hippocampus-can represent a spatial map under the appropriate experimental conditions.


Assuntos
Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Comportamento Espacial/fisiologia , Animais , Comportamento Animal/fisiologia , Mapeamento Encefálico/métodos , Eletrocorticografia , Masculino , Ratos , Ratos Long-Evans
10.
Neuroimage ; 240: 118283, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34147628

RESUMO

The thalamic pulvinar and the lateral intraparietal area (LIP) share reciprocal anatomical connections and are part of an extensive cortical and subcortical network involved in spatial attention and oculomotor processing. The goal of this study was to compare the effective connectivity of dorsal pulvinar (dPul) and LIP and to probe the dependency of microstimulation effects on task demands and spatial tuning properties of a given brain region. To this end, we applied unilateral electrical microstimulation in the dPul (mainly medial pulvinar) and LIP in combination with event-related BOLD fMRI in monkeys performing fixation and memory-guided saccade tasks. Microstimulation in both dPul and LIP enhanced task-related activity in monosynaptically-connected fronto-parietal cortex and along the superior temporal sulcus (STS) including putative face patch locations, as well as in extrastriate cortex. LIP microstimulation elicited strong activity in the opposite homotopic LIP while no homotopic activation was found with dPul stimulation. Both dPul and LIP stimulation also elicited activity in several heterotopic cortical areas in the opposite hemisphere, implying polysynaptic propagation of excitation. Despite extensive activation along the intraparietal sulcus evoked by LIP stimulation, there was a difference in frontal and occipital connectivity elicited by posterior and anterior LIP stimulation sites. Comparison of dPul stimulation with the adjacent but functionally dissimilar ventral pulvinar also showed distinct connectivity. On the level of single trial timecourses within each region of interest (ROI), most ROIs did not show task-dependence of stimulation-elicited response modulation. Across ROIs, however, there was an interaction between task and stimulation, and task-specific correlations between the initial spatial selectivity and the magnitude of stimulation effect were observed. Consequently, stimulation-elicited modulation of task-related activity was best fitted by an additive model scaled down by the initial response amplitude. In summary, we identified overlapping and distinct patterns of thalamocortical and corticocortical connectivity of pulvinar and LIP, highlighting the dorsal bank and fundus of STS as a prominent node of shared circuitry. Spatial task-specific and partly polysynaptic modulations of cue and saccade planning delay period activity in both hemispheres exerted by unilateral pulvinar and parietal stimulation provide insight into the distributed interhemispheric processing underlying spatial behavior.


Assuntos
Imageamento por Ressonância Magnética/métodos , Rede Nervosa/fisiologia , Lobo Parietal/fisiologia , Pulvinar/fisiologia , Movimentos Sacádicos/fisiologia , Comportamento Espacial/fisiologia , Animais , Estimulação Elétrica/métodos , Macaca mulatta , Masculino , Microeletrodos , Rede Nervosa/diagnóstico por imagem , Lobo Parietal/diagnóstico por imagem , Pulvinar/diagnóstico por imagem
11.
J Vis Exp ; (170)2021 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-33871459

RESUMO

Although the general architecture of the hippocampus is similar along its longitudinal axis, recent studies have revealed prominent differences in molecular, anatomical and functional criteria suggesting a division into different sub-circuits along its rostro-caudal extent. Owing to differential connectivity and function the most fundamental distinction is made between the dorsal and the ventral hippocampus, which are preferentially involved in spatial and emotional processing, respectively. Accordingly, in vivo work regarding spatial memory formation has focused on the dorsal hippocampus. In contrast, electro-physiological in vitro recordings have been preferentially performed on intermediate-ventral hippocampus, largely motivated by factors like slice viability and circuit integrity. To allow for direct correlation of in vivo data on spatial processing with in vitro data we have adapted previous sectioning methods to obtain highly viable transverse brain slices from the dorsal-intermediate hippocampus for long-term recordings of principal cells and interneurons in the dentate gyrus. As spatial behavior is routinely analyzed in adult mice, we have combined this transversal slicing procedure with the use of protective solutions to enhance viability of brain tissue from mature animals. We use this approach for mice of about 3 months of age. The method offers a good alternative to the coronal preparation which is frequently used for in vitro studies on dorsal hippocampus. We compare these two preparations in terms of quality of recordings and preservation of morphological features of recorded neurons.


Assuntos
Hipocampo/fisiologia , Animais , Feminino , Masculino , Camundongos , Neurônios/fisiologia , Técnicas de Patch-Clamp , Comportamento Espacial/fisiologia
12.
PLoS One ; 16(4): e0249739, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33831106

RESUMO

The aim of this study was analyze the effect of playing against biological matched and un-matched opposition, on physical performance and spatial exploration behavior of youth basketball players. Thirty under-14 to 16 basketball players were assigned to different teams according to maturity status (Pre-, Mid-, and Post-Peak Height Velocity [PHV]), and participated in basketball matches against matched (same maturity status), and un-matched (different maturity status) opposition. Maturity status was estimated considering the percentage of predicted adult height. Workload data was collected via inertial devices (IMUs) and Ultra-Wide Band (UWB)-based system. Heart rate was recorded with individual HR monitors. The Pre-PHV performed significantly more accelerations and decelerations and explored more space against matched opposition. Against un-matched opposition, the Pre-PHV presented higher average speed, body impacts, and Player Load. Both Mid- and Post-PHV covered more distance against matched opposition than against Pre-PHV. Games against Pre-PHV involved lower distance covered, average speed, Player Load, and higher accelerations and decelerations, than against Mid- and Post-PHV. The Pre-PHV athletes performed a higher number of accelerations and decelerations comparing to the Mid and Post-PHV players. Also, a significant interaction effect (group x time) was found in distance covered, average speed, body impacts, and Player Load. The type of opposition influenced physical performance and spatial exploration behavior during basketball matches, particularly of less-mature players. Based on present findings, practitioners can select the most suitable game format, considering the physical, technical, tactical, and psychological development needs, individualizing training stimulus.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Comportamento Exploratório/fisiologia , Comportamento Espacial/fisiologia , Aceleração , Adolescente , Atletas , Criança , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Desempenho Físico Funcional , Corrida/fisiologia , Carga de Trabalho
13.
Nat Neurosci ; 24(6): 863-872, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33859438

RESUMO

To guide spatial behavior, the brain must retrieve memories that are appropriately associated with different navigational contexts. Contextual memory might be mediated by cell ensembles in the hippocampal formation that alter their responses to changes in context, processes known as remapping and realignment in the hippocampus and entorhinal cortex, respectively. However, whether remapping and realignment guide context-dependent spatial behavior is unclear. To address this issue, human participants learned object-location associations within two distinct virtual reality environments and subsequently had their memory tested during functional MRI (fMRI) scanning. Entorhinal grid-like representations showed realignment between the two contexts, and coincident changes in fMRI activity patterns consistent with remapping were observed in the hippocampus. Critically, in a third ambiguous context, trial-by-trial remapping and realignment in the hippocampal-entorhinal network predicted context-dependent behavior. These results reveal the hippocampal-entorhinal mechanisms mediating human contextual memory and suggest that the hippocampal formation plays a key role in spatial behavior under uncertainty.


Assuntos
Mapeamento Encefálico/métodos , Córtex Entorrinal/diagnóstico por imagem , Córtex Entorrinal/fisiologia , Hipocampo/diagnóstico por imagem , Hipocampo/fisiologia , Comportamento Espacial/fisiologia , Adulto , Feminino , Previsões , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Realidade Virtual , Adulto Jovem
14.
Neurorehabil Neural Repair ; 35(3): 207-219, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33514272

RESUMO

BACKGROUND: Motor performance is a complex process controlled in task-specific spatial frames of reference (FRs). Movements can be made within the framework of the body (egocentric FR) or external space (exocentric FR). People with stroke have impaired reaching, which may be related to deficits in movement production in different FRs. OBJECTIVE: To characterize rapid motor responses to changes in the number of degrees of freedom for movements made in different FRs and their relationship with sensorimotor and cognitive impairment in individuals with mild chronic stroke. METHODS: Healthy and poststroke individuals moved their hand along the contralateral forearm (egocentric task) and between targets in the peripersonal space (exocentric task) without vision while flexing the trunk. Trunk movement was blocked in randomized trials. RESULTS: For the egocentric task, controls produced the same endpoint trajectories in both conditions (free- and blocked-trunk) by preserving similar shoulder-elbow interjoint coordination (IJC). However, endpoint trajectories were dissimilar because of altered IJC in stroke. For the exocentric task, controls produced the same endpoint trajectories when the trunk was free or blocked by rapidly changing the IJC, whereas this was not the case in stroke. Deficits in exocentric movement after stroke were related to cognitive but not sensorimotor impairment. CONCLUSIONS: Individuals with mild stroke have deficits rapidly responding to changing conditions for complex reaching tasks. This may be related to cognitive deficits and limitations in the regulation of tonic stretch reflex thresholds. Such deficits should be considered in rehabilitation programs encouraging the reintegration of the affected arm into activities of daily living.


Assuntos
AVC Hemorrágico/fisiopatologia , AVC Isquêmico/fisiopatologia , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Comportamento Espacial/fisiologia , Extremidade Superior/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Espaço Pessoal , Índice de Gravidade de Doença , Tronco/fisiopatologia
15.
Sci Rep ; 11(1): 2611, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33510396

RESUMO

Interpersonal space (IPS) is the area around the body that individuals maintain between themselves and others during social interactions. When others violate our IPS, feeling of discomfort rise up, urging us to move farther away and reinstate an appropriate interpersonal distance. Previous studies showed that when individuals are exposed to closeness of an unknown person (a confederate), the skin conductance response (SCR) increases. However, if the SCR is modulated according to participant's preferred IPS is still an open question. To test this hypothesis, we recorded the SCR in healthy participants when a confederate stood in front of them at various distances simulating either an approach or withdrawal movement (Experiment 1). Then, the comfort-distance task was adopted to measure IPS: participants stop the confederate, who moved either toward or away from them, when they felt comfortable with other's proximity (Experiment 2). We found higher SCR when the confederate stood closer to participants simulating an IPS intrusion, compared to when the confederate moved farther away. Crucially, we provide the first evidence that SCR, acting as a warning signal, contributes to interpersonal distance preference suggesting a functional link between behavioral components of IPS regulation and the underlying physiological processes.


Assuntos
Resposta Galvânica da Pele , Relações Interpessoais , Espaço Pessoal , Adulto , Ansiedade , Feminino , Humanos , Masculino , Comportamento Espacial/fisiologia , Adulto Jovem
16.
PLoS One ; 16(1): e0245940, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33507979

RESUMO

It was shown earlier that dogs, when selecting between two dishes with snacks placed in front of them, left and right, prefer to turn either clockwise or counterclockwise or randomly in either direction. This preference (or non-preference) is individually consistent in all trials but it is biased in favor of north if they choose between dishes positioned north and east or north and west, a phenomenon denoted as "pull of the north". Here, we replicated these experiments indoors, in magnetic coils, under natural magnetic field and under magnetic field shifted 90° clockwise. We demonstrate that "pull of the north" was present also in an environment without any outdoor cues and that the magnetic (and not topographic) north exerted the effect. The detailed analysis shows that the phenomenon involves also "repulsion of the south". The clockwise turning preference in the right-preferring dogs is more pronounced in the S-W combination, while the counterclockwise turning preference in the left-preferring dogs is pronounced in the S-E combination. In this way, south-placed dishes are less frequently chosen than would be expected, while the north-placed dishes are apparently more preferred. Turning preference did not correlate with the motoric paw laterality (Kong test). Given that the choice of a dish is visually guided, we postulate that the turning preference was determined by the dominant eye, so that a dominant right eye resulted in clockwise, and a dominant left eye in counterclockwise turning. Assuming further that magnetoreception in canines is based on the radical-pair mechanism, a "conflict of interests" may be expected, if the dominant eye guides turning away from north, yet the contralateral eye "sees the north", which generally acts attractive, provoking body alignment along the north-south axis.


Assuntos
Comportamento Animal/fisiologia , Sinais (Psicologia) , Campos Magnéticos , Orientação Espacial/fisiologia , Comportamento Espacial/fisiologia , Animais , Cães , Feminino , Masculino
17.
Nat Hum Behav ; 5(4): 447-457, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33398140

RESUMO

Interacting pedestrians in a crowd spontaneously adjust their footsteps and align their respective stepping phases. This self-organization phenomenon is known as synchronization. However, it is unclear why and how synchronization forms spontaneously under different density conditions, or what functional benefit synchronization offers for the collective motion of humans. Here, we conducted a single-file crowd motion experiment that directly tracked the alternating movement of both legs of interacting pedestrians. We show that synchronization is most likely to be triggered at the same density at which the flow rate of pedestrians reaches a maximum value. We demonstrate that synchronization is established in response to an insufficient safety distance between pedestrians, and that it enables pedestrians to realize efficient collective stepping motion without the occurrence of inter-person collisions. These findings provide insights into the collective motion behaviour of humans and may have implications for understanding pedestrian synchronization-induced wobbling, for example, of bridges.


Assuntos
Aglomeração , Processos Grupais , Pedestres/estatística & dados numéricos , Comportamento Espacial/fisiologia , Caminhada/fisiologia , Humanos , Relações Interpessoais , Movimento/fisiologia
18.
J Mot Behav ; 53(2): 166-175, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32188359

RESUMO

The current study examined whether young adults' avoidance behaviours differed when circumventing a larger versus smaller interferer. It was expected that avoidance behaviours (repulsion) would be affected by the interferer's size (i.e., greater repulsion for larger body size). Participants (n = 20) walked along an 8 m pathway towards a goal while avoiding either a larger or smaller sized male interferer who stood stationary facing forward, backward, left, or right and were located 2, 4, or 6 m from the participants' starting position. Results revealed that there was an effect of interferer body size (personal-characteristics) and orientation (situational-characteristics) on M-L clearance between the interferer and participant at the time of crossing, suggesting that repulsion magnitudes are scaled to an interferer's closest body surface.


Assuntos
Aprendizagem da Esquiva/fisiologia , Percepção de Tamanho/fisiologia , Comportamento Espacial/fisiologia , Caminhada/fisiologia , Adolescente , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Adulto Jovem
19.
Annu Rev Entomol ; 66: 435-461, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-32966103

RESUMO

Color vision is widespread among insects but varies among species, depending on the spectral sensitivities and interplay of the participating photoreceptors. The spectral sensitivity of a photoreceptor is principally determined by the absorption spectrum of the expressed visual pigment, but it can be modified by various optical and electrophysiological factors. For example, screening and filtering pigments, rhabdom waveguide properties, retinal structure, and neural processing all influence the perceived color signal. We review the diversity in compound eye structure, visual pigments, photoreceptor physiology, and visual ecology of insects. Based on an overview of the current information about the spectral sensitivities of insect photoreceptors, covering 221 species in 13 insect orders, we discuss the evolution of color vision and highlight present knowledge gaps and promising future research directions in the field.


Assuntos
Evolução Biológica , Visão de Cores , Olho Composto de Artrópodes/fisiologia , Insetos/fisiologia , Células Fotorreceptoras de Invertebrados/fisiologia , Animais , Olho Composto de Artrópodes/citologia , Pigmentos da Retina/genética , Comportamento Espacial/fisiologia
20.
Elife ; 92020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33325370

RESUMO

AKT is implicated in neurological disorders. AKT has three isoforms, AKT1/AKT2/AKT3, with brain cell type-specific expression that may differentially influence behavior. Therefore, we examined single Akt isoform, conditional brain-specific Akt1, and double Akt1/3 mutant mice in behaviors relevant to neuropsychiatric disorders. Because sex is a determinant of these disorders but poorly understood, sex was an experimental variable in our design. Our studies revealed AKT isoform- and sex-specific effects on anxiety, spatial and contextual memory, and fear extinction. In Akt1 mutant males, viral-mediated AKT1 restoration in the prefrontal cortex rescued extinction phenotypes. We identified a novel role for AKT2 and overlapping roles for AKT1 and AKT3 in long-term memory. Finally, we found that sex-specific behavior effects were not mediated by AKT expression or activation differences between sexes. These results highlight sex as a biological variable and isoform- or cell type-specific AKT signaling as potential targets for improving treatment of neuropsychiatric disorders.


Assuntos
Comportamento Animal/fisiologia , Encéfalo/metabolismo , Extinção Psicológica/fisiologia , Transtornos Mentais/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Memória Espacial/fisiologia , Animais , Feminino , Masculino , Memória de Longo Prazo/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Isoformas de Proteínas , Caracteres Sexuais , Comportamento Espacial/fisiologia
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