scholarly journals Sensory Ecology of Ostariophysan Alarm Substances

Author(s):  
Caio Maximino ◽  
Rhayra Xavier do Carmo Silva ◽  
Kimberly dos Santos Campos ◽  
Jeiseane Souza de Oliveira ◽  
Sueslene Prado Rocha ◽  
...  

Chemical communication of predation risk has evolved multiple times in fish species, with the conspecific alarm substance (CAS) contemporaneously being the most well understood mechanism. CAS is released after epithelial damage, usually when prey fish is captured by a predator, and elicits neurobehavioral adjustments in conspecifics which increase the probability of avoiding predation. As such, CAS is a partial predator stimulus, eliciting risk assessment-like and avoidance behaviors, and disrupting the predator sequence. The present paper reviews the distribution and putative composition of CAS in fish, and presents a model for the neural processing of these structures by the olfactory and the brain aversive systems. Applications of CAS in the behavioral neurosciences and neuropharmacology are also presented, exploiting the potential of model fish (e.g., zebrafish, guppies, minnows) on neurobehavioral research.

Author(s):  
Caio Maximino ◽  
Rhayra Xavier do Carmo Silva ◽  
Kimberly dos Santos Campos ◽  
Jeiseane Souza de Oliveira ◽  
Sueslene Prado Rocha ◽  
...  

Chemical communication of predation risk has evolved multiple times in fish species, with the conspecific alarm substance (CAS) contemporaneously being the most well understood mechanism. CAS is released after epithelial damage, usually when prey fish is captured by a predator, and elicits neurobehavioral adjustments in conspecifics which increase the probability of avoiding predation. As such, CAS is a partial predator stimulus, eliciting risk assessment-like and avoidance behaviors, and disrupting the predator sequence. The present paper reviews the distribution and putative composition of CAS in fish, and presents a model for the neural processing of these structures by the olfactory and the brain aversive systems. Applications of CAS in the behavioral neurosciences and neuropharmacology are also presented, exploiting the potential of model fish (e.g., zebrafish, guppies, minnows) on neurobehavioral research.


2010 ◽  
Vol 21 (3) ◽  
pp. 532-536 ◽  
Author(s):  
M. C. O. Ferrari ◽  
C. K. Elvidge ◽  
C. D. Jackson ◽  
D. P. Chivers ◽  
G. E. Brown

Author(s):  
Riitta Salmelin ◽  
Jan Kujala ◽  
Mia Liljeström

When seeking to uncover the brain correlates of language processing, timing and location are of the essence. Magnetoencephalography (MEG) offers them both, with the highest sensitivity to cortical activity. MEG has shown its worth in revealing cortical dynamics of reading, speech perception, and speech production in adults and children, in unimpaired language processing as well as developmental and acquired language disorders. The MEG signals, once recorded, provide an extensive selection of measures for examination of neural processing. Like all other neuroimaging tools, MEG has its own strengths and limitations of which the user should be aware in order to make the best possible use of this powerful method and to generate meaningful and reliable scientific data. This chapter reviews MEG methodology and how MEG has been used to study the cortical dynamics of language.


2010 ◽  
Vol 6 (4) ◽  
pp. 525-528 ◽  
Author(s):  
S. Mourabit ◽  
S. D. Rundle ◽  
J. I. Spicer ◽  
K. A. Sloman

Alarm substances elicit behavioural responses in a wide range of animals but effects on early embryonic development are virtually unknown. Here we investigated whether skin injury-induced alarm substances caused physiological responses in embryos produced by two Danio species ( Danio rerio and Danio albolineatus ). Both species showed more rapid physiological development in the presence of alarm substance, although there were subtle differences between them: D. rerio had advanced muscle contraction and heart function, whereas D. albolineatus had advanced heart function only. Hence, alarm cues from injured or dying fish may be of benefit to their offspring, inducing physiological responses and potentially increasing their inclusive fitness.


2021 ◽  
Vol 118 (20) ◽  
pp. e2022491118
Author(s):  
Jeroen M. van Baar ◽  
David J. Halpern ◽  
Oriel FeldmanHall

Political partisans see the world through an ideologically biased lens. What drives political polarization? Although it has been posited that polarization arises because of an inability to tolerate uncertainty and a need to hold predictable beliefs about the world, evidence for this hypothesis remains elusive. We examined the relationship between uncertainty tolerance and political polarization using a combination of brain-to-brain synchrony and intersubject representational similarity analysis, which measured committed liberals’ and conservatives’ (n = 44) subjective interpretation of naturalistic political video material. Shared ideology between participants increased neural synchrony throughout the brain during a polarizing political debate filled with provocative language but not during a neutrally worded news clip on polarized topics or a nonpolitical documentary. During the political debate, neural synchrony in mentalizing and valuation networks was modulated by one’s aversion to uncertainty: Uncertainty-intolerant individuals experienced greater brain-to-brain synchrony with politically like-minded peers and lower synchrony with political opponents—an effect observed for liberals and conservatives alike. Moreover, the greater the neural synchrony between committed partisans, the more likely that two individuals formed similar, polarized attitudes about the debate. These results suggest that uncertainty attitudes gate the shared neural processing of political narratives, thereby fueling polarized attitude formation about hot-button issues.


2021 ◽  
Author(s):  
Kenta Uchida ◽  
Albert A. Burkle ◽  
Daniel T. Blumstein

Ecotourism promotes conservation efforts while also allowing for low impact observation of wildlife. Many ecotourists photograph wildlife and photography plays an important role in focusing the public’s attention on nature. Although photography is commonly believed to be a low impact activity, how the visual stimulus of a camera influences wildlife remains unknown. Since animals are known to fear eyes pointed towards them, we predicted that a camera with a large zoom lens would increase animal’s vigilance levels. Using yellow-bellied marmots (Marmota flaviventer) as a mammalian model, and adopting a behavioural approach to identify how marmots responded to cameras, we experimentally quantified vigilance and flight initiation distance towards humans when marmots were approached with and without a camera. While a camera was pointed at an individual, marmots allocated less time to searching predators and increased time to looking at the observer than they did without a camera. However, whether a camera was pointed at a marmot or not had no effect on the distance the marmot flushed. Our results indicated that cameras distracted marmots but did not influence subsequent risk assessment (i.e., flight initiation distance); marmots may be curious about cameras but were not threatened by them. Capturing animals’ attentions reduces searching for predators and may increase the vulnerability to predation. Therefore, regulating photography in locations where predation risk is high or vulnerable species ranges’ overlap with humans may be required to reduce photography’s impact on wildlife.


2020 ◽  
Vol 117 (36) ◽  
pp. 22522-22531 ◽  
Author(s):  
Mehran Spitmaan ◽  
Hyojung Seo ◽  
Daeyeol Lee ◽  
Alireza Soltani

A long-lasting challenge in neuroscience has been to find a set of principles that could be used to organize the brain into distinct areas with specific functions. Recent studies have proposed the orderly progression in the time constants of neural dynamics as an organizational principle of cortical computations. However, relationships between these timescales and their dependence on response properties of individual neurons are unknown, making it impossible to determine how mechanisms underlying such a computational principle are related to other aspects of neural processing. Here, we developed a comprehensive method to simultaneously estimate multiple timescales in neuronal dynamics and integration of task-relevant signals along with selectivity to those signals. By applying our method to neural and behavioral data during a dynamic decision-making task, we found that most neurons exhibited multiple timescales in their response, which consistently increased from parietal to prefrontal and cingulate cortex. While predicting rates of behavioral adjustments, these timescales were not correlated across individual neurons in any cortical area, resulting in independent parallel hierarchies of timescales. Additionally, none of these timescales depended on selectivity to task-relevant signals. Our results not only suggest the existence of multiple canonical mechanisms for increasing timescales of neural dynamics across cortex but also point to additional mechanisms that allow decorrelation of these timescales to enable more flexibility.


i-Perception ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 204166952096661
Author(s):  
Yasuhiro Takeshima

Audiovisual integration relies on temporal synchrony between visual and auditory stimuli. The brain rapidly adapts to audiovisual asynchronous events by shifting the timing of subjective synchrony in the direction of the leading modality of the most recent event, a process called rapid temporal recalibration. This phenomenon is the flexible function of audiovisual synchrony perception. Previous studies found that neural processing speed based on spatial frequency (SF) affects the timing of subjective synchrony. This study examined the effects of SF on the rapid temporal recalibration process by discriminating whether the presentation of the visual and auditory stimuli was simultaneous. I compared the magnitudes of the recalibration effect between low and high SF visual stimuli using two techniques. First, I randomly presented each SF accompanied by a tone during one session, then in a second experiment, only a single SF was paired with the tone throughout the one session. The results indicated that rapid recalibration occurred regardless of difference in presented SF between preceding and test trials. The recalibration magnitude did not significantly differ between the SF conditions. These findings confirm that intersensory temporal process is important to produce rapid recalibration and suggest that rapid recalibration can be induced by the simultaneity judgment criterion changes attributed to the low-level temporal information of audiovisual events.


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