Defensive Behavior Research Articles

Role of L- and T-type voltage-dependent calcium channels in the hierarchical organization of defensive responses to electrical stimulation of the rat dorsolateral periaqueductal gray

Stimulation of the dorsal half of the rat periaqueductal gray (DPAG) with 60-Hz pulses of increasing intensity, 30-μA pulses of increasing frequency, or increasing doses of an excitatory amino acid elicits sequential defensive responses of exophthalmia, immobility, trotting, galloping, and jumping. These responses may be controlled by voltage-gated calcium channel-specific firing patterns. Indeed, a previous study showed that microinjection of the DPAG with 15 nmol of verapamil, a putative blocker of L-type calcium channels, attenuated all defensive responses to electrical stimulation at the same site as the injection. Accordingly, here we investigated the effects of microinjection of lower doses (0.7 and 7 nmol) of both verapamil and mibefradil, a preferential blocker of T-type calcium channels, on DPAG-evoked defensive behaviors of the male rat. Behaviors were recorded either 24 h before or 10 min, 24 h, and 48 h after microinjection. Effects were analyzed by both threshold logistic analysis and repeated measures analysis of variance for treatment by session interactions. Data showed that the electrodes were all located within the dorsolateral PAG. Compared to the effects of saline, verapamil significantly attenuated exophthalmia, immobility, and trotting. Mibefradil significantly attenuated exophthalmia and marginally attenuated immobility while facilitating trotting. While galloping was not attenuated by either antagonist, jumping was unexpectedly attenuated by 0.7 nmol verapamil only. These results suggest that T-type calcium channels are involved in the low-threshold freezing responses of exophthalmia and immobility, whereas L-type calcium channels are involved in the trotting response that precedes the full-fledged escape responses of galloping and jumping.

Wing-slapping: A defensive behavior by honey bees against ants.

Wing-slapping: A defensive behavior by honey bees against ants.

A vagal-brainstem interoceptive circuit for cough-like defensive behaviors in mice.

Coughing is a respiratory behavior that plays a crucial role in protecting the respiratory system. Here we show that the nucleus of the solitary tract (NTS) in mice contains heterogenous neuronal populations that differentially control breathing. Within these subtypes, activation of tachykinin 1 (Tac1)-expressing neurons triggers specific respiratory behaviors that, as revealed by our detailed characterization, are cough-like behaviors. Chemogenetic silencing or genetic ablation of Tac1 neurons inhibits cough-like behaviors induced by tussive challenges. These Tac1 neurons receive synaptic inputs from the bronchopulmonary chemosensory and mechanosensory neurons in the vagal ganglion and coordinate medullary regions to control distinct aspects of cough-like defensive behaviors. We propose that these Tac1 neurons in the NTS are a key component of the airway-vagal-brain neural circuit that controls cough-like defensive behaviors in mice and that they coordinate the downstream modular circuits to elicit the sequential motor pattern of forceful expiratory responses.

The influence of individuality on performance traits in mussels: Assessments based on defensive behavior and physiology

Cultured Mytilus coruscus fall-offs regularly led to the reduction of harvest yields of suspension-cultured mussels. High temperature and marine pollutants affect mussel physiological health, which increases the risk of mussel fall-offs and results in yield declines. In this study, we classified mussels into proactive and reactive groups based on their self-organizing behavior after air exposure stress and investigated the differences in defense performance of different group mussels. Proactive mussels were found to have a significantly higher byssus number, adhesion area, and gene expression in the mussel foot protein mfp5 and the byssus collagen preCOL-P. Exposure of mussels to high temperature and different concentrations of BDE-47 revealed a decrease in byssus performance and byssus gene expression in both proactive and reactive groups, but the decreased level of expression of the proactive mussel foot proteins mfp5 and mfp6 was significantly less than that of the reactive mussels. Our study found that proactive mussels have more and better byssuses, better adhesion and defense ability, and greater adaptability under higher temperature and pollutant-exposed conditions. The performance of byssus is correlated with the individuality of stress coping, providing a new direction for future mussel selection breeding and aquaculture.

Defensive behavior: Sensing threats from terrestrial and aerial predators

The dorsal periaqueductal gray (dPAG) contains a tonically GABAergic network controlling defensive responses. Determining how this intrinsic dPAG inhibitory circuit functions might provide critical insights into how anti-predatory responses are organized.

Fear, defense, and emotion: A neuroethological understanding of the negative valence research domain criteria.

We describe the close correspondence between predatory imminence continuum theory (PICT) and the National Institute of Mental Health's Research Domain Criteria (RDoC) for negative valence. RDoC's negative valence constructs relate aversively motivated behavioral reactions to various levels of threat. PICT divides defensive responses into distinct modes that vary along a continuum of the psychological closeness of predatory threat. While there is a close correspondence between PICT modes and negative valence threat constructs, based on PICT, we describe some potential elaborations of RDoC constructs. Both have consonant views of fear and anxiety and provide explicit distinctions between these emotional states, relating them to specific defensive behaviors and functions. We describe recent data that causally implicate human subjective emotional states with amygdala activity, which is also critical for defensive behavior. We conclude that attention to neuroethological views of defense can advance our understanding of the etiology and treatment of anxiety and stress disorders. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Defensive plasticity in South American rattlesnakes Crotalus durissus

Reptiles exhibit defensive responses in diverse ways, influenced by situational factors. Snakes, such as the South American rattlesnake Crotalus durissus, display complex defensive responses, adapting tactics based on circumstances when encountering potential predators. Environmental and intrinsic parameters shape snake behaviour during predator encounters. This study employs distinct stimuli to investigate behavioural changes and whether snakes adapt defensive strategies. We compare the behaviours of rattlesnakes before and after an aversive stimulus involving physical contact. Following encounters with higher-risk stimuli, snakes become more defensive.Findings reveal that snakes alter strategies based on threat intensity. This phenomenon might be influenced by the potential cost of defense and prior interactions with predators. The study underscores the intricate nature of snake defensive behaviour. Keywords: behavioural plasticity, antipredator behaviour, aversive stimulus, behavioural cost, active behaviours

Modeling Host-Pathogen Interactions in C. elegans: Lessons Learned from Pseudomonas aeruginosa Infection.

Infections, such as that by the multiresistant opportunistic bacterial pathogen Pseudomonas aeruginosa, may pose a serious health risk, especially on vulnerable patient populations. The nematode Caenorhabditis elegans provides a simple organismal model to investigate both pathogenic mechanisms and the emerging role of innate immunity in host protection. Here, we review the virulence and infection strategies of P. aeruginosa and host defenses of C. elegans. We summarize the recognition mechanisms of patterns of pathogenesis, including novel pathogen-associated molecular patterns and surveillance immunity of translation, mitochondria, and lysosome-related organelles. We also review the regulation of antimicrobial and behavioral defenses by the worm's neuroendocrine system. We focus on how discoveries in this rich field align with well-characterized evolutionary conserved protective pathways, as well as on potential crossovers to human pathogenesis and innate immune responses.

Neural Decoding and Feature Selection Techniques for Closed-Loop Control of Defensive Behavior.

Many psychiatric disorders involve excessive avoidant or defensive behavior, such as avoidance in anxiety and trauma disorders or defensive rituals in obsessive-compulsive disorders. Developing algorithms to predict these behaviors from local field potentials (LFPs) could serve as foundational technology for closed-loop control of such disorders. A significant challenge is identifying the LFP features that encode these defensive behaviors. We analyzed LFP signals from the infralimbic cortex and basolateral amygdala of rats undergoing tone-shock conditioning and extinction, standard for investigating defensive behaviors. We utilized a comprehensive set of neuro-markers across spectral, temporal, and connectivity domains, employing SHapley Additive exPlanations for feature importance evaluation within Light Gradient-Boosting Machine models. Our goal was to decode three commonly studied avoidance/defensive behaviors: freezing, bar-press suppression, and motion (accelerometry), examining the impact of different features on decoding performance. Band power and band power ratio between channels emerged as optimal features across sessions. High-gamma (80-150 Hz) power, power ratios, and inter-regional correlations were more informative than other bands that are more classically linked to defensive behaviors. Focusing on highly informative features enhanced performance. Across 4 recording sessions with 16 subjects, we achieved an average coefficient of determination of 0.5357 and 0.3476, and Pearson correlation coefficients of 0.7579 and 0.6092 for accelerometry jerk and bar press rate, respectively. Utilizing only the most informative features revealed differential encoding between accelerometry and bar press rate, with the former primarily through local spectral power and the latter via inter-regional connectivity. Our methodology demonstrated remarkably low time complexity, requiring <110 ms for training and <1 ms for inference. Our results demonstrate the feasibility of accurately decoding defensive behaviors with minimal latency, using LFP features from neural circuits strongly linked to these behaviors. This methodology holds promise for real-time decoding to identify physiological targets in closed-loop psychiatric neuromodulation.

Interspecific variation in the defensive responses of brown frogs to alien predators

AbstractAlien species impact native amphibians through various direct effects, including predation, and pose a significant threat to naïve prey populations. In this study, we exposed tadpoles of three brown frog species (Rana dalmatina, Rana latastei, and Rana temporaria) to the olfactory cues of two alien predators, the pond slider (Trachemys scripta) and red swamp crayfish (Procambarus clarkii), and compared their responses to those induced by the aquatic larvae of a widespread native predator, the Southern hawker (Aeshna cyanea). We recorded two tadpole defensive behaviors, the proportion of time they were active and the number of freezing events. Both agile frog species, R. dalmatina and R. latastei, showed moderate responses to red swamp crayfish kairomones and strong responses to both odonate larvae and pond sliders. In contrast, the common frog (R. temporaria) displayed a less intense response to crayfish with respect to odonate larvae, and a negligible response to pond sliders. Long-lasting coexistence with either European pond turtles or pond sliders may explain the strength of agile frogs’ response toward the alien species; while, the historical range of the white-clawed crayfish (Austropotamobius pallipes) overlapped that of the common frog, enhancing the co-option of alien crayfish cues by this anuran species.

A Case Study on Seasonal Behaviour of Aphodius elegans Allibert an Endocoprid Dung Beetle

Dung beetles (Scarabaeidae) classified into endocoprid, paracoprid, and telecoprid beetles, are fascinating insects with various behaviors. The study focuses on behaviour of endocoprid beetles Aphodius elegans Allibert, found in Bumdeling, Trashi Yangts Bhutan. The observational and scan sampling methods were employed during the study. These beetles locate dung using antennae and dig inside it, resembling a boat propelled by oars. They are active during warm weather and bury themselves under dung during cold. Beetles defecate semi solid feces after dung foraging. They mimic death as defensive and antipredator behaviour. They prefer moist dung pats for burial and use repeated attempts and strongholds of hindwings to initiate flight. This study substantiates the diverse fascinating behaviors of a less-focused group of insects to gain a deeper understanding of their interactions with ecology.

Construction of Power System Network Security Defense Behavior Decision-making Model based on Artificial Intelligence Technology

According to the needs of power grid monitoring architecture and information security cooperation protection, this project builds a multi-level, deeply distributed active security cooperation defense mode. A complete implementation method is proposed from the perspective of model architecture and function mechanism. The optimal defense strategy based on grey correlation is studied according to the characteristics of cooperation between regions. In this way, the coordination between the equipment is realized to achieve multi-level protection from the host layer to the security equipment layer and then to the network layer. Multiple detection mechanisms are used to realize the comprehensive detection and integrated judgment of abnormal documents in the cloud environment. This provides maximum protection for cloud users. Experiments show that this method can effectively suppress the malicious attacks of malicious users and reduce the damage caused by viruses. In this way, both the cloud and the customer are protected.

Against network attacks in renewable power plants: Malicious behavior defense for federated learning

As reducing carbon emissions can relieve environmental concerns, networks-supported renewable power plants are being built more and more. Inevitable network attacks have become a serious threat in increasing and distributed power plants. Leveraging federated learning for training the joint model to detect network attacks in distributed power plants is efficient, but two malicious behaviors of cheating and free-riding are unavoidable. To this end, we design a new SDN based federated security architecture and propose a carbon-credit-rewarded consensus verification mechanism in this architecture to deal with malicious behaviors. For this architecture, on the one hand, considering geographical conditions of renewable power plants, multi-controller SDN is adopted in network to solve some security problems at root and to avoid single point of failure. On the other hand, the segmentation of collaborative zones reduces communication cost effectively. The proposed mechanism establishes consensus bearer and realizes the election of consensus bearer by cross-validation of client detection models. Only the excellent models are aggregated to mitigate cheating of malicious clients. Carbon emissions credit is introduced as an incentive in the proposed mechanism. The redistribution of carbon emissions credit improves the performance of global detection model and avoids free-riding. Moreover, the economic nature of carbon emissions credit enhances the spillover effect of carbon emissions trading market on the reduction of carbon emissions. The experimental results revealed that the proposed architecture has excellent performance, and can handle malicious behaviors effectively.

Comparing behaviours induced by natural memory retrieval and optogenetic reactivation of an engram ensemble in mice.

Memories are thought to be stored within sparse collections of neurons known as engram ensembles. Neurons active during a training episode are allocated to an engram ensemble ('engram neurons'). Memory retrieval is initiated by external sensory or internal cues present at the time of training reactivating engram neurons. Interestingly, optogenetic reactivation of engram ensemble neurons alone in the absence of external sensory cues is sufficient to induce behaviour consistent with memory retrieval in mice. However, there may exist differences between the behaviours induced by natural retrieval cues or artificial engram reactivation. Here, we compared two defensive behaviours (freezing and the syllable structure of ultrasonic vocalizations, USVs) induced by sensory cues present at training (natural memory retrieval) and optogenetic engram ensemble reactivation (artificial memory retrieval) in a threat conditioning paradigm in the same mice. During natural memory recall, we observed a strong positive correlation between freezing levels and distinct USV syllable features (characterized by an unsupervised algorithm, MUPET (Mouse Ultrasonic Profile ExTraction)). Moreover, we observed strikingly similar behavioural profiles in terms of freezing and USV characteristics between natural memory recall and artificial memory recall in the absence of sensory retrieval cues. Although our analysis focused on two behavioural measures of threat memory (freezing and USV characteristics), these results underscore the similarities between threat memory recall triggered naturally and through optogenetic reactivation of engram ensembles. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.

An ethologically relevant paradigm to assess defensive response to looming visual contrast stimuli

In the animal kingdom, threat information is perceived mainly through vision. The subcortical visual pathway plays a critical role in the rapid processing of visual information-induced fear, and triggers a response. Looming-evoked behavior in rodents, mimicking response to aerial predators, allowed identify the neural circuitry underlying instinctive defensive behaviors; however, the influence of disk/background contrast on the looming-induced behavioral response has not been examined, either in rats or mice. We studied the influence of the dark disk/gray background contrast in the type of rat and mouse defensive behavior in the looming arena, and we showed that rat and mouse response as a function of disk/background contrast adjusted to a sigmoid-like relationship. Both sex and age biased the contrast-dependent response, which was dampened in rats submitted to retinal unilateral or bilateral ischemia. Moreover, using genetically manipulated mice, we showed that the three type of photoresponsive retinal cells (i.e., cones, rods, and intrinsically photoresponsive retinal ganglion cells (ipRGCs)), participate in the contrast-dependent response, following this hierarchy: cones > > rods > > > ipRGCs. The cone and rod involvement was confirmed using a mouse model of unilateral non-exudative age-related macular degeneration, which only damages canonical photoreceptors and significantly decreased the contrast sensitivity in the looming arena.

TRPV1 nociceptors are required to optimize antigen-specific primary antibody responses to novel antigens

BackgroundKey to the advancement of the field of bioelectronic medicine is the identification of novel pathways of neural regulation of immune function. Sensory neurons (termed nociceptors) recognize harmful stimuli and initiate a protective response by eliciting pain and defensive behavior. Nociceptors also interact with immune cells to regulate host defense and inflammatory responses. However, it is still unclear whether nociceptors participate in regulating primary IgG antibody responses to novel antigens.MethodsTo understand the role of transient receptor potential vanilloid 1 (TRPV1)-expressing neurons in IgG responses, we generated TRPV1-Cre/Rosa-ChannelRhodopsin2 mice for precise optogenetic activation of TRPV1 + neurons and TRPV1-Cre/Lox-diphtheria toxin A mice for targeted ablation of TRPV1-expressing neurons. Antigen-specific antibody responses were longitudinally monitored for 28 days.ResultsHere we show that TRPV1 expressing neurons are required to develop an antigen-specific immune response. We demonstrate that selective optogenetic stimulation of TRPV1+ nociceptors during immunization significantly enhances primary IgG antibody responses to novel antigens. Further, mice rendered deficient in TRPV1- expressing nociceptors fail to develop primary IgG antibody responses to keyhole limpet hemocyanin or haptenated antigen.ConclusionThis functional and genetic evidence indicates a critical role for nociceptor TRPV1 in antigen-specific primary antibody responses to novel antigens. These results also support consideration of potential therapeutic manipulation of nociceptor pathways using bioelectronic devices to enhance immune responses to foreign antigens.

Prey can detect predators via electroreception in air

Predators and prey benefit from detecting sensory cues of each other's presence. As they move through their environment, terrestrial animals accumulate electrostatic charge. Because electric charges exert forces at a distance, a prey animal could conceivably sense electrical forces to detect an approaching predator. Here, we report such a case of a terrestrial animal detecting its predators by electroreception. We show that predatory wasps are charged, thus emit electric fields, and that caterpillars respond to such fields with defensive behaviors. Furthermore, the mechanosensory setae of caterpillars are deflected by these electrostatic forces and are tuned to the wingbeat frequency of their insect predators. This ability unveils a dimension of the sensory interactions between prey and predators and is likely widespread among terrestrial animals.

The impact of high-fat diet consumption and inulin fiber supplementation on anxiety-related behaviors and liver oxidative status in female Wistar rats

BackgroundObesity is a worldwide public health problem associated with cognitive and mental health problems in both humans and rats. Studies assessing the effect of fiber supplementation on behavioral deficits and oxidative stress caused by high-fat diet (HFD) consumption in female rats are still scarce. We hypothesized that HFD consumption would lead to anxiety-related behavior and hepatic oxidative stress and that inulin would protect against these changes. We analyzed the impact of HFD-induced obesity combined with fiber supplementation (inulin) on anxiety-related defensive behavior and hepatic oxidative stress. ResultsFemale rats were fed a high-fat diet (HFD; 45%) for nine weeks to induce obesity. The administration of inulin was found to decrease the adiposity index in both the control and obese groups. The consumption of a HFD combined with inulin supplementation resulted in a reduction in both CAT activity and carbonylated protein levels, leading to a shift in the hepatic redox balance. Interestingly, the behavioral data were conflicting. Specifically, animals that consumed a high-fat diet and received inulin showed signs of impaired learning and memory caused by obesity. The HFD did not impact anxiety-related behaviors in the female rats. However, inulin appears to have an anxiolytic effect, in the ETM, when associated with the HFD. On the other hand, inulin appears to have affected the locomotor activity in the HFD in both open field and light-dark box. ConclusionOur results show that consumption of a HFD induced obesity in female rats, similar to males. However, HFD consumption did not cause a consistent increase in anxiety-related behaviors in female Wistar rats. Treatment with inulin at the dosage used did not exert consistent changes on the behavior of the animals, but attenuated the abdominal WAT expansion and the hepatic redox imbalance elicited by high-fat diet-induced obesity.

Macrophage-Inspired marine antifouling coating with dynamic surfaces based on regulation of dynamic covalent bonds

Macrophages can kill bacteria and viruses by releasing free radicals, which provides a possible approach to construct antifouling coatings with dynamic surfaces that release free radicals if the breaking of dynamic covalent bonds is precisely regulated. Herein, inspired by the defensive behavior of macrophages of releasing free radicals to kill bacteria and viruses, a marine antifouling coating composed of polyurethane incorporating dimethylglyoxime (PUx-DMG) is prepared by precise regulation of dynamic oxime-urethane covalent bonds. The obtained alkyl radical (R·) derived from the cleavage of the oxime-urethane bonds manages to effectively suppress the attachment of marine biofouling. Moreover, the intrinsic dynamic surface makes it difficult for biofouling to adhere and ultimately achieves sustainable antifouling property. Notably, the PU50-DMG coating not only presents efficient antibacterial and antialgae properties, but also prevents macroorganisms from settling in the sea for up to 4 months. This provides a pioneer broad-spectrum strategy to explore the marine antifouling coatings.

Mosquitoes do not influence Cotton Mouse (Peromyscus gossypinus) giving-up densities

Abstract It is commonly recognized that predation and the risk of predation can have profound effects on behaviors and population ecology of prey. Comparatively, little attention has been paid to the trade-offs hosts make to manage the risk of parasitism, but there is evidence that hosts make behavioral trade-offs to avoid parasitism in ways that resemble those made by prey animals under the risk of predation. Mosquitoes are common hematophagous ectoparasites which parasitize a wide range of vertebrates, resulting in blood loss, distraction, and disease transmission. Many hosts engage in defensive behaviors to repel or kill mosquitoes and these behaviors likely come at the expense of activities such as foraging and vigilance for predators. We placed a mosquito attractant (BG-Sweetscent) and repellant (allethrin) near artificial foraging patches in areas where mosquitoes were common and measured the amount of grain left after a night of foraging (giving-up density) to investigate whether mosquitoes influenced Cotton Mouse (Peromyscus gossypinus) foraging. We predicted that in patches with mosquito attractants, mosquito harassment would cause mice to engage in defensive behaviors which would distract or deter them from foraging, resulting in less grain consumption relative to control patches. Conversely, we predicted that in mosquito-repellent patches, mice would experience less harassment, resulting in more grain consumption. Indoor arena trials found no evidence that the mosquito treatments influenced cotton mouse behavior in the absence of mosquitoes. However, we found no evidence that mosquito treatments affected giving-up densities.