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1.
Cell ; 186(25): 5554-5568.e18, 2023 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-38065080

RESUMEN

Cancer cells are regulated by oncogenic mutations and microenvironmental signals, yet these processes are often studied separately. To functionally map how cell-intrinsic and cell-extrinsic cues co-regulate cell fate, we performed a systematic single-cell analysis of 1,107 colonic organoid cultures regulated by (1) colorectal cancer (CRC) oncogenic mutations, (2) microenvironmental fibroblasts and macrophages, (3) stromal ligands, and (4) signaling inhibitors. Multiplexed single-cell analysis revealed a stepwise epithelial differentiation phenoscape dictated by combinations of oncogenes and stromal ligands, spanning from fibroblast-induced Clusterin (CLU)+ revival colonic stem cells (revCSCs) to oncogene-driven LRIG1+ hyper-proliferative CSCs (proCSCs). The transition from revCSCs to proCSCs is regulated by decreasing WNT3A and TGF-ß-driven YAP signaling and increasing KRASG12D or stromal EGF/Epiregulin-activated MAPK/PI3K flux. We find that APC loss and KRASG12D collaboratively limit access to revCSCs and disrupt stromal-epithelial communication-trapping epithelia in the proCSC fate. These results reveal that oncogenic mutations dominate homeostatic differentiation by obstructing cell-extrinsic regulation of cell-fate plasticity.


Asunto(s)
Proteínas Proto-Oncogénicas p21(ras) , Transducción de Señal , Diferenciación Celular , Oncogenes , Proteínas Proto-Oncogénicas p21(ras)/genética , Células Madre , Humanos , Animales , Ratones , Linaje de la Célula
2.
Mol Cell ; 82(8): 1589-1602.e5, 2022 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-35263628

RESUMEN

A polyubiquitin chain can adopt a variety of shapes, depending on how the ubiquitin monomers are joined. However, the relevance of linkage for the signaling functions of polyubiquitin chains is often poorly understood because of our inability to control or manipulate this parameter in vivo. Here, we present a strategy for reprogramming polyubiquitin chain linkage by means of tailor-made, linkage- and substrate-selective ubiquitin ligases. Using the polyubiquitylation of the budding yeast replication factor PCNA in response to DNA damage as a model case, we show that altering the features of a polyubiquitin chain in vivo can change the fate of the modified substrate. We also provide evidence for redundancy between distinct but structurally similar linkages, and we demonstrate by proof-of-principle experiments that the method can be generalized to targets beyond PCNA. Our study illustrates a promising approach toward the in vivo analysis of polyubiquitin signaling.


Asunto(s)
Poliubiquitina , Ubiquitina-Proteína Ligasas , ADN , Daño del ADN , Poliubiquitina/genética , Antígeno Nuclear de Célula en Proliferación/genética , Ubiquitina/genética , Ubiquitina-Proteína Ligasas/genética
3.
Proc Natl Acad Sci U S A ; 121(17): e2400086121, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38621132

RESUMEN

Vision can provide useful cues about the geometric properties of an object, like its size, distance, pose, and shape. But how the brain merges these properties into a complete sensory representation of a three-dimensional object is poorly understood. To address this gap, we investigated a visual illusion in which humans misperceive the shape of an object due to a small change in one eye's retinal image. We first show that this illusion affects percepts of a highly familiar object under completely natural viewing conditions. Specifically, people perceived their own rectangular mobile phone to have a trapezoidal shape. We then investigate the perceptual underpinnings of this illusion by asking people to report both the perceived shape and pose of controlled stimuli. Our results suggest that the shape illusion results from distorted cues to object pose. In addition to yielding insights into object perception, this work informs our understanding of how the brain combines information from multiple visual cues in natural settings. The shape illusion can occur when people wear everyday prescription spectacles; thus, these findings also provide insight into the cue combination challenges that some spectacle wearers experience on a regular basis.


Asunto(s)
Ilusiones , Humanos , Encéfalo , Señales (Psicología)
4.
Proc Natl Acad Sci U S A ; 121(18): e2312992121, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38648479

RESUMEN

Cortical neurons exhibit highly variable responses over trials and time. Theoretical works posit that this variability arises potentially from chaotic network dynamics of recurrently connected neurons. Here, we demonstrate that chaotic neural dynamics, formed through synaptic learning, allow networks to perform sensory cue integration in a sampling-based implementation. We show that the emergent chaotic dynamics provide neural substrates for generating samples not only of a static variable but also of a dynamical trajectory, where generic recurrent networks acquire these abilities with a biologically plausible learning rule through trial and error. Furthermore, the networks generalize their experience in the stimulus-evoked samples to the inference without partial or all sensory information, which suggests a computational role of spontaneous activity as a representation of the priors as well as a tractable biological computation for marginal distributions. These findings suggest that chaotic neural dynamics may serve for the brain function as a Bayesian generative model.


Asunto(s)
Modelos Neurológicos , Neuronas , Neuronas/fisiología , Teorema de Bayes , Red Nerviosa/fisiología , Dinámicas no Lineales , Humanos , Aprendizaje/fisiología , Animales , Encéfalo/fisiología
5.
BMC Biol ; 22(1): 73, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38561772

RESUMEN

BACKGROUND: Quorum sensing (QS) is the ability of microorganisms to assess local clonal density by measuring the extracellular concentration of signal molecules that they produce and excrete. QS is also the only known way of bacterial communication that supports the coordination of within-clone cooperative actions requiring a certain threshold density of cooperating cells. Cooperation aided by QS communication is sensitive to cheating in two different ways: laggards may benefit from not investing in cooperation but enjoying the benefit provided by their cooperating neighbors, whereas Liars explicitly promise cooperation but fail to do so, thereby convincing potential cooperating neighbors to help them, for almost free. Given this double vulnerability to cheats, it is not trivial why QS-supported cooperation is so widespread among prokaryotes. RESULTS: We investigated the evolutionary dynamics of QS in populations of cooperators for whom the QS signal is an inevitable side effect of producing the public good itself (cue-based QS). Using spatially explicit agent-based lattice simulations of QS-aided threshold cooperation (whereby cooperation is effective only above a critical cumulative level of contributions) and three different (analytical and numerical) approximations of the lattice model, we explored the dynamics of QS-aided threshold cooperation under a feasible range of parameter values. We demonstrate three major advantages of cue-driven cooperation. First, laggards cannot wipe out cooperation under a wide range of reasonable environmental conditions, in spite of an unconstrained possibility to mutate to cheating; in fact, cooperators may even exclude laggards at high cooperation thresholds. Second, lying almost never pays off, if the signal is an inevitable byproduct (i.e., the cue) of cooperation; even very cheap fake signals are selected against. And thirdly, QS is most useful if local cooperator densities are the least predictable, i.e., if their lattice-wise mean is close to the cooperation threshold with a substantial variance. CONCLUSIONS: Comparing the results of the four different modeling approaches indicates that cue-driven threshold cooperation may be a viable evolutionary strategy for microbes that cannot keep track of past behavior of their potential cooperating partners, in spatially viscous and in well-mixed environments alike. Our model can be seen as a version of the famous greenbeard effect, where greenbeards coexist with defectors in a evolutionarily stable polymorphism. Such polymorphism is maintained by the condition-dependent trade-offs of signal production which are characteristic of cue-based QS.


Asunto(s)
Señales (Psicología) , Percepción de Quorum , Evolución Biológica , Bacterias , Hidrolasas , Comunicación
6.
Neuroimage ; 300: 120849, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39265955

RESUMEN

Despite the potential link between stress-induced reward dysfunctions and the development of mental problems, limited human research has investigated the specific impacts of chronic stress on the dynamics of reward processing. Here we aimed to investigate the relationship between chronic academic stress and the dynamics of reward processing (i.e., reward anticipation and reward consumption) using event-related potential (ERP) technology. Ninety healthy undergraduates who were preparing for the National Postgraduate Entrance Examination (NPEE) participated in the study and completed a two-door reward task, their chronic stress levels were assessed via the Perceived Stress Scale (PSS). The results showed that a lower magnitude of reward elicited more negative amplitudes of cue-N2 during the anticipatory phase, and reward omission elicited more negative amplitudes of FRN compared to reward delivery especially in high reward conditions during the consummatory phase. More importantly, the PSS score exhibited a U-shaped relationship with cue-N2 amplitudes regardless of reward magnitude during the anticipatory phase; and FRN amplitudes toward reward omission in high reward condition during the consummatory phase. These findings suggest that individuals exposed to either low or high levels of chronic stress, as opposed to moderate stress levels, exhibited a heightened reward anticipation, and an augmented violation of expectations or affective response when faced with relatively more negative outcomes.

7.
Eur J Neurosci ; 60(3): 4332-4345, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38858176

RESUMEN

People with Parkinson's disease often exhibit improvements in motor tasks when exposed to external sensory cues. While the effects of different types of sensory cues on motor functions in Parkinson's disease have been widely studied, the underlying neural mechanism of these effects and the potential of sensory cues to alter the motor cortical activity patterns and functional connectivity of cortical motor areas are still unclear. This study aims to compare changes in oxygenated haemoglobin, deoxygenated haemoglobin and correlations among different cortical regions of interest during wrist movement under different external stimulus conditions between people with Parkinson's disease and controls. Ten Parkinson's disease patients and 10 age- and sex-matched neurologically healthy individuals participated, performing repetitive wrist flexion and extension tasks under auditory and visual cues. Changes in oxygenated and deoxygenated haemoglobin in motor areas were measured using functional near-infrared spectroscopy, along with electromyograms from wrist muscles and wrist movement kinematics. The functional near-infrared spectroscopy data revealed significantly higher neural activity changes in the Parkinson's disease group's pre-motor area compared to controls (p = 0.006), and functional connectivity between the supplementary motor area and pre-motor area was also significantly higher in the Parkinson's disease group when external sensory cues were present (p = 0.016). These results indicate that external sensory cues' beneficial effects on motor tasks are linked to changes in the functional connectivity between motor areas responsible for planning and preparation of movements.


Asunto(s)
Señales (Psicología) , Corteza Motora , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/fisiopatología , Femenino , Masculino , Persona de Mediana Edad , Anciano , Corteza Motora/fisiopatología , Espectroscopía Infrarroja Corta , Muñeca , Electromiografía , Movimiento/fisiología , Fenómenos Biomecánicos/fisiología , Hemoglobinas/metabolismo
8.
Eur J Neurosci ; 59(7): 1500-1518, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38185906

RESUMEN

Discrete alcohol cues and contexts are relapse triggers for people with alcohol use disorder exerting particularly powerful control over behaviour when they co-occur. Here, we investigated the neural substrates subserving the capacity for alcohol-associated contexts to elevate responding to an alcohol-predictive conditioned stimulus (CS). Specifically, rats were trained in a distinct 'alcohol context' to respond by entering a fluid port during a discrete auditory CS that predicted the delivery of alcohol and were familiarized with a 'neutral context' wherein alcohol was never available. When conditioned CS responding was tested by presenting the CS without alcohol, we found that augmenting glutamatergic activity in the nucleus accumbens (NAc) shell by microinfusing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) reduced responding to an alcohol CS in an alcohol, but not neutral, context. Further, AMPA microinfusion robustly affected behaviour, attenuating the number, duration and latency of CS responses selectively in the alcohol context. Although dopaminergic inputs to the NAc shell were previously shown to be necessary for CS responding in an alcohol context, here, chemogenetic excitation of ventral tegmental area (VTA) dopamine neurons and their inputs to the NAc shell did not affect CS responding. Critically, chemogenetic excitation of VTA dopamine neurons affected feeding behaviour and elevated c-fos immunoreactivity in the VTA and NAc shell, validating the chemogenetic approach. These findings enrich our understanding of the substrates underlying Pavlovian responding for alcohol and reveal that the capacity for contexts to modulate responding to discrete alcohol cues is delicately underpinned by the NAc shell.


Asunto(s)
Señales (Psicología) , Núcleo Accumbens , Humanos , Ratas , Animales , Núcleo Accumbens/fisiología , Ratas Long-Evans , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico , Etanol/farmacología , Condicionamiento Operante/fisiología
9.
Eur J Neurosci ; 59(7): 1567-1584, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38314648

RESUMEN

The spontaneously hypertensive rat (SHR) is a selectively bred animal strain that is frequently used to model attention-deficit hyperactivity disorder (ADHD) because of certain genetically determined behavioural characteristics. To test the hypothesis that the characteristically altered response to positive reinforcement in SHRs may be due to altered phasic dopamine response to reward, we measured phasic dopamine signals in the SHRs and Sprague Dawley (SD) rats using in vivo fast-scan cyclic voltammetry. The effects of the dopamine reuptake inhibitor, methylphenidate, on these signals were also studied. Phasic dopamine signals during the pairing of a sensory cue with electrical stimulation of midbrain dopamine neurons were significantly smaller in the SHRs than in the SD rats. Over repeated pairings, the dopamine response to the sensory cue increased, whereas the response to the electrical stimulation of dopamine neurons decreased, similarly in both strains. However, the final amplitude of the response to the sensory cue after pairing was significantly smaller in SHRs than in the SD rats. Methylphenidate increased responses to sensory cues to a significantly greater extent in the SHRs than in the SD rats, due largely to differences in the low dose effect. At a higher dose, methylphenidate increased responses to sensory cues and electrical stimulation similarly in SHRs and SD rats. The smaller dopamine responses may explain the reduced salience of reward-predicting cues previously reported in the SHR, whereas the action of methylphenidate on the cue response suggests a potential mechanism for the therapeutic effects of low-dose methylphenidate in ADHD.


Asunto(s)
Estimulantes del Sistema Nervioso Central , Metilfenidato , Ratas , Animales , Metilfenidato/farmacología , Metilfenidato/uso terapéutico , Ratas Endogámicas SHR , Dopamina , Ratas Endogámicas WKY , Ratas Sprague-Dawley , Modelos Animales de Enfermedad , Estimulantes del Sistema Nervioso Central/farmacología
10.
Eur J Neurosci ; 59(9): 2373-2390, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38303554

RESUMEN

Humans have the remarkable ability to integrate information from different senses, which greatly facilitates the detection, localization and identification of events in the environment. About 466 million people worldwide suffer from hearing loss. Yet, the impact of hearing loss on how the senses work together is rarely investigated. Here, we investigate how a common sensory impairment, asymmetric conductive hearing loss (AHL), alters the way our senses interact by examining human orienting behaviour with normal hearing (NH) and acute AHL. This type of hearing loss disrupts auditory localization. We hypothesized that this creates a conflict between auditory and visual spatial estimates and alters how auditory and visual inputs are integrated to facilitate multisensory spatial perception. We analysed the spatial and temporal properties of saccades to auditory, visual and audiovisual stimuli before and after plugging the right ear of participants. Both spatial and temporal aspects of multisensory integration were affected by AHL. Compared with NH, AHL caused participants to make slow, inaccurate and unprecise saccades towards auditory targets. Surprisingly, increased weight on visual input resulted in accurate audiovisual localization with AHL. This came at a cost: saccade latencies for audiovisual targets increased significantly. The larger the auditory localization errors, the less participants were able to benefit from audiovisual integration in terms of saccade latency. Our results indicate that observers immediately change sensory weights to effectively deal with acute AHL and preserve audiovisual accuracy in a way that cannot be fully explained by statistical models of optimal cue integration.


Asunto(s)
Localización de Sonidos , Percepción Visual , Humanos , Femenino , Adulto , Masculino , Percepción Visual/fisiología , Localización de Sonidos/fisiología , Adulto Joven , Movimientos Sacádicos/fisiología , Percepción Auditiva/fisiología , Pérdida Auditiva/fisiopatología , Estimulación Luminosa/métodos , Estimulación Acústica/métodos , Percepción Espacial/fisiología
11.
Biochem Biophys Res Commun ; 718: 150071, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-38735136

RESUMEN

Inducing fear memory extinction by re-presenting a conditioned stimulus (CS) is the foundation of exposure therapy for post-traumatic stress disorder (PTSD). Investigating differences in the ability of different CS presentation patterns to induce extinction learning is crucial for improving this type of therapy. Using a trace fear conditioning paradigm in mice, we demonstrate that spaced presentation of the CS facilitated the extinction of a strong fear memory to a greater extent than continuous CS presentation. These results lay the groundwork for developing more effective exposure therapy techniques for PTSD.


Asunto(s)
Condicionamiento Clásico , Extinción Psicológica , Miedo , Memoria , Ratones Endogámicos C57BL , Animales , Miedo/fisiología , Miedo/psicología , Extinción Psicológica/fisiología , Memoria/fisiología , Masculino , Ratones , Condicionamiento Clásico/fisiología , Trastornos por Estrés Postraumático/psicología , Trastornos por Estrés Postraumático/fisiopatología , Condicionamiento Psicológico/fisiología
12.
Cerebellum ; 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38702560

RESUMEN

Two vestibular signals, rotational and inertial cues, converge for the perception of complex motion. However, how vestibular perception is built on neuronal behaviors and decision-making processes, especially during the simultaneous presentation of rotational and inertial cues, has yet to be elucidated in humans. In this study, we analyzed the perceptual responses of 20 participants after pairwise rotational experiments, comprised of four control and four test sessions. In both control and test sessions, participants underwent clockwise and counterclockwise rotations in head-down and head-up positions. The difference between the control and test sessions was the head re-orientation relative to gravity after rotations, thereby providing only rotational cues in the control sessions and both rotational and inertial cues in the test sessions. The accuracy of perceptual responses was calculated by comparing the direction of rotational and inertial cues acquired from participants with that predicted by the velocity-storage model. The results showed that the accuracy of rotational perception ranged from 80 to 95% in the four control sessions but significantly decreased to 35 to 75% in the four test sessions. The accuracy of inertial perception in the test sessions ranged from 50 to 70%. The accuracy of rotational perception improved with repetitive exposure to the simultaneous presentation of both rotational and inertial cues, while the accuracy of inertial perception remained steady. The results suggested a significant interaction between rotational and inertial perception and implied that vestibular perception acquired in patients with vestibular disorders are potentially inaccurate.

13.
J Exp Biol ; 2024 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-39324315

RESUMEN

By selectively focusing on a specific portion of the environment, animals can solve the problem of information overload, toning down irrelevant inputs and concentrating only on the relevant ones. This may be of particular relevance for animals such as the jumping spider, which possess a wide visual field of almost 360° and thus could benefit from a low-cost system for sharpening attention. Jumping spiders have a modular visual system composed of four pairs of eyes, of which only the two frontal eyes (i.e., AMEs) are motile, whereas the other secondary pairs remain immobile. We hypothesized that jumping spiders can exploit both principal and secondary eyes for stimulus detection and attentional shift, with the two systems working synergistically. In Experiment 1 we investigated AMEs' attentional responses following a spatial cue presented to the secondary eyes. In Experiment 2, we tested for enhanced attention in the secondary eyes' visual field congruent with the direction of the AMEs' focus. In both experiments, we observed that animals were faster and more accurate in detecting a target when it appeared in a direction opposite to that of the initial cue. In contrast with our initial hypothesis, these results would suggest that attention is segregated across eyes, with each system working on compensating the other by attending to different spatial locations.

14.
J Exp Biol ; 227(19)2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39246153

RESUMEN

Understanding the processes that guide carnivores in finding and selecting prey is a fundamental, unresolved challenge in sensory biology. To our knowledge, no published work has yet revealed the complete structural identities of compounds that cue preferences by generalist predators for different prey species. With this research imperative in mind, we determined the chemistry driving consumer preferences for live intact prey using two generalist predatory species (sea stars, Pisaster ochraceus; whelks, Acanthinucella spirata), along with two foundation prey species (mussels, Mytilus californianus; barnacles, Balanus glandula), inhabiting rocky, wave-swept shores. Each prey species is known to secrete either a 29.6 kDa (named 'KEYSTONEin') or a 199.6 kDa (named 'MULTIFUNCin') glycoprotein as a contact-chemical cue. Here, experimental manipulations utilized faux prey consisting of cleaned barnacle or mussel shells infused with KEYSTONEin, MULTIFUNCin or seawater (control) gels. Whelks exhibited a strong penchant for MULTIFUNCin over KEYSTONEin, irrespective of shell type. In contrast, sea stars generally preferred KEYSTONEin over MULTIFUNCin, but this preference shifted depending on the experimental context in which they encountered physical (shell) and chemical (glycoprotein) stimuli. This study ultimately demonstrates clear and contrasting chemical preferences between sea stars and whelks. It highlights the importance of experimental setting in determining chemical preferences. Finally, it shows that prey preferences by these predators hinge only on one or two contact-protein cues, without the need for quality coding via fluid-borne compounds, low-molecular-weight substances or mixture blends.


Asunto(s)
Conducta Predatoria , Thoracica , Animales , Thoracica/fisiología , Equinodermos/fisiología , Señales (Psicología) , Bivalvos/fisiología , Glicoproteínas/química , Mytilus/fisiología
15.
Anim Cogn ; 27(1): 50, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39052136

RESUMEN

We examined the possibility of a cross-modal effect in naïve Cotesia vestalis, a parasitoid wasp of diamondback moth larvae, by using artificial flower models of four colours (blue, green, yellow, and red) in the absence or presence of floral scent collected from Brassica rapa inflorescences. In a four-choice test, regardless of the floral scent, non-starved female wasps visited green and yellow models significantly more often than blue and red ones, although no significant difference was observed between visits to the green and yellow models. They seldom visited blue and red models. When starved, the wasps became even more particular, visiting yellow significantly more frequently than green models, irrespective of the presence of the floral scent, indicating that they preferred to use yellow visual cues in their food search. Furthermore, a factorial analysis of variance revealed a significant effect of the interaction between model colour and floral scent on the wasps' visits to flower models. The floral scent induced starved and non-starved wasps to visit yellow and green models about twice as often as without the scent. A cross-modal effect of olfactory perception on the use of chromatic information by wasps may allow them to search efficiently for food sources.


Asunto(s)
Percepción de Color , Flores , Odorantes , Avispas , Animales , Avispas/fisiología , Femenino , Señales (Psicología) , Conducta de Elección , Mariposas Nocturnas/parasitología , Percepción Olfatoria , Color
16.
Biol Lett ; 20(9): 20240299, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39317328

RESUMEN

Like many insects, bumblebees use polarized light (PL) to orient and navigate. The celestial PL pattern is strongest when the sun is close to the horizon, during the dim light of dawn and dusk. In the dim light, the sensitivity of the compound eyes may not be sufficient for detecting PL or landmarks, and it has previously been hypothesized that bumblebees rely on PL from their more sensitive ocelli to navigate at dawn and dusk. Here, we tested this hypothesis using a combination of electrophysiological and behavioural tests. Specifically, we investigate whether bumblebee ocelli can detect PL and explore how the PL contribution from the ocelli and compound eyes is affected by light intensity. We find that bumblebee ocelli do indeed have PL sensitivity and that PL information can be used to guide behaviour in dim light. In bright light, however, both the compound eyes and ocelli are important for the detection of PL. Our results support the hypothesis that bumblebees use PL information from the ocelli at the low light levels that occur around dawn and dusk, and this may support their ability to forage during these periods.


Asunto(s)
Ojo Compuesto de los Artrópodos , Luz , Animales , Abejas/fisiología , Ojo Compuesto de los Artrópodos/fisiología
17.
Exp Brain Res ; 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39304549

RESUMEN

When exposed to a predictable external perturbation, humans typically generate anticipatory postural adjustments (APAs) to minimize potential body disturbance. After a single session of training, individuals demonstrated the ability to rely solely on an auditory cue to elicit appropriate APAs in response to an external postural perturbation. However, whether the generation of APAs requires directional specific training remains unclear. The aim of this study was to assess whether directional-specific training with auditory cues is necessary for the generation of appropriate APA responses. Ten young adults were exposed to external perturbations targeting either their left or right shoulders, with or without an auditory cue prior to the physical impact. Electromyography (EMG) activities of sixteen trunk and leg muscles and center-of-pressure (COP) displacements were recorded and analyzed during the anticipatory and compensatory phases of postural control. Outcome measures included the latencies and integrals of muscle activities, COP displacements, and indices of co-contraction and reciprocal activation of muscles. The results revealed that, after training with right-side perturbations accompanied by an auditory cue, young adults exhibited earlier and more efficient APA responses to right-side perturbations relying only on the auditory cue. Additionally, they displayed earlier APA responses in some muscles to left-side perturbations, although these responses were less efficient. Our findings suggest that young adults could generate effective APAs to external perturbations relying on an auditory cue after a single training session; however, these responses were directional specific.

18.
Exp Brain Res ; 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39316096

RESUMEN

Efficient responses in dynamic environments rely on a combination of readiness and flexibility, regulated by anticipatory and online response control mechanisms. The latter are required when a motor response needs to be reprogrammed or when flanker stimuli induce response conflict and they are crucially modulated by anticipatory signals such as response and conflict expectations. The mutual influence and interplay of these control processes remain to be elucidated. Our behavioral study employed a novel combined response cueing/conflict task designed to test for interactive effects of response reprogramming and conflict resolution and their modulation by expectations. To this end, valid and invalid response cues were combined with congruent and incongruent target flankers. Expectations were modulated by systematically manipulating the proportions of valid versus invalid cues and congruent versus incongruent flanker stimuli in different task blocks. Reaction time and accuracy were assessed in thirty-one healthy volunteers. The results revealed response reprogramming and conflict resolution interactions for both behavioral measures, modulated by response and conflict expectations. Accuracy decreased disproportionally when invalidly cued targets with incongruent flankers were least expected. These findings support coordinated and partially overlapping anticipatory and online response control mechanisms within motor-cognitive networks.

19.
Curr Psychiatry Rep ; 26(9): 470-486, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39083129

RESUMEN

BACKGROUND: Immersive Virtual Reality (IVR) has shown promise in the assessment, understanding, and treatment of eating disorders (EDs), providing a dynamic platform for clinical innovation. This scoping review aims to synthesize the recent advancements and applications of IVR in addressing these complex psychological disorders. METHODS: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols, focusing on studies published in the past five years. It included peer-reviewed papers that used IVR for ED assessment, examination, or treatment. A comprehensive database search provided a selection of relevant articles, which were then methodically screened and analyzed. RESULTS: Twenty studies met the inclusion criteria, with a primary focus on Anorexia Nervosa (AN), Bulimia Nervosa (BN), and Binge Eating Disorder (BED). The application of IVR was categorized into three areas: assessment, understanding, and treatment. IVR was found to be an effective tool in assessing body image distortions and emotional responses to food, providing insights that are less accessible through traditional methods. Furthermore, IVR offers innovative treatment approaches by facilitating exposure therapy, modifying body-related biases, and enabling emotional regulation through embodied experiences. The studies demonstrate IVR's potential to improve body image accuracy, reduce food-related anxieties, and support behavioral changes in ED patients. CONCLUSION: IVR stands out as a transformative technology in the field of EDs, offering comprehensive benefits across diagnostic, therapeutic, and experiential domains. The IVR's ability to simulate the brain's predictive coding mechanisms provides a powerful avenue for delivering embodied, experiential interventions that can help recalibrate distorted body representations and dysfunctional affective predictive models implicated in EDs. Future research should continue to refine these applications, ensuring consistent methodologies and wider clinical trials to fully harness IVR's potential in clinical settings.


Asunto(s)
Trastornos de Alimentación y de la Ingestión de Alimentos , Humanos , Trastornos de Alimentación y de la Ingestión de Alimentos/terapia , Realidad Virtual , Terapia de Exposición Mediante Realidad Virtual/métodos , Bulimia Nerviosa/terapia
20.
J Chem Ecol ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38722477

RESUMEN

Zeugodacus cucurbitae and Z. tau are two major fruit fly pests of cucurbitaceous plants in the tropical and subtropical regions. The former species has a broader host range and wider world distribution than the latter. With global climate change, Z. tau shows great potential for geographical expansion with several invasion records in recent years. Males of both species are attracted to cue lure (CL) (and raspberry ketone (RK), a deacetyl derivative of CL), a common male lure used in fruit fly population detection, monitoring and control programs. Males of both species are also known to respond to zingerone (ZN), which are produced by some rainforest orchids. Previous studies have shown that fruit fly-male lure interactions are unique to species and lure types, and significantly impact the success of a lure-based fruit fly control program. We seek to compare the attraction of Z. cucurbitae and Z. tau males to CL, RK and ZN via Probit behavioral assays. Our results showed that CL is more attractive to Z. cucurbitae and Z. tau males than RK, while ZN is a poor lure for both species. Attraction Z. tau to CL is slightly lower than Z. cucurbitae, but the former is at least 1.71 times less attractive to RK than the latter. Together with published information on species' sexual development, our current study indicates a lure-based control program via male annihilation technique for Z. tau will be more challenging than Z. cucurbitae and should incorporate other integrated pest management strategies for a desirable outcome.

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