Drosophila Mechanical Nociceptors Preferentially Sense Localized Poking

Mechanical nociception is an evolutionarily conserved sensory process required for the survival of living organisms. Previous studies have revealed much about the neural circuits and key sensory molecules in mechanical nociception, but the cellular mechanisms adopted by nociceptors in force detection remain elusive. To address this issue, we study the mechanosensation of a fly larval nociceptor (class IV da neurons, c4da) using a customized mechanical device. We find that c4da are sensitive to mN-scale forces and make uniform responses to the forces applied at different dendritic regions. Moreover, c4da showed a greater sensitivity to more localized forces, consistent with them being able to sense the poking of sharp objects, such as wasp ovipositor. Further analysis reveals that high morphological complexity, mechanosensitivity to lateral tension and active signal propagation in the dendrites altogether facilitate the mechanosensitivity and sensory features of c4da. In particular, we discover that Piezo and Ppk1/Ppk26, two key mechanosensory molecules, make differential but additive contributions to the mechanosensation of c4da. In all, our results provide updates into understanding how c4da process mechanical signals at the cellular level and reveal the contributions of key molecules.

SOME MECHANISMS OF TROPES FORMATION

Статья посвящена рассмотрению эмотивных и когнитивных процессов, в результате действия которых формируются тропы. Исследуется чувственный процесс восприятия, условия его протекания и результаты, а также когнитивный процесс метафоризации, его механизмы и операции как части кода культуры. На основе анализа «классических» тропов выделяются признаки, позволяющие отнести средство выразительности к числу тропов. The article is devoted to the consideration of emotive and cognitive processes, as a result of which tropes are formed. The sensory process of perception, the conditions for its course and results, as well as the cognitive process of metaphorization, its mechanisms and operations as a part of the cultural code are explored. Certain types of «classical» tropes are considered. On the basis of the analysis of the «classical» tropes, features that allow the means of expressiveness to be attributed to the number of tropes are identified.

Bumblebee electric charge stimulates floral volatile emissions in Petunia integrifolia but not in Antirrhinum majus

The timing of volatile organic compound (VOC) emission by flowering plants often coincides with pollinator foraging activity. Volatile emission is often considered to be paced by environmental variables, such as light intensity, and/or by circadian rhythmicity. The question arises as to what extent pollinators themselves provide information about their presence, in keeping with their long co-evolution with flowering plants. Bumblebees are electrically charged and provide electrical stimulation when visiting plants, as measured via the depolarisation of electric potential in the stem of flowers. Here we test the hypothesis that the electric charge of foraging bumblebees increases the floral volatile emissions of bee pollinated plants. We investigate the change in VOC emissions of two bee-pollinated plants (Petunia integrifolia and Antirrhinum majus) exposed to the electric charge typical of foraging bumblebees. P. integrifolia slightly increases its emissions of a behaviorally and physiologically active compound in response to visits by foraging bumblebees, presenting on average 121 pC of electric charge. We show that for P. integrifolia, strong electrical stimulation (600–700 pC) promotes increased volatile emissions, but this is not found when using weaker electrical charges more representative of flying pollinators (100 pC). Floral volatile emissions of A. majus were not affected by either strong (600–700 pC) or weak electric charges (100 pC). This study opens a new area of research whereby the electrical charge of flying insects may provide information to plants on the presence and phenology of their pollinators. As a form of electroreception, this sensory process would bear adaptive value, enabling plants to better ensure that their attractive chemical messages are released when a potential recipient is present.

The other-race effect on the McGurk effect in infancy

This study investigated the difference in the McGurk effect between own-race-face and other-race-face stimuli among Japanese infants from 5 to 9 months of age. The McGurk effect results from infants using information from a speaker’s face in audiovisual speech integration. We hypothesized that the McGurk effect varies with the speaker’s race because of the other-race effect, which indicates an advantage for own-race faces in our face processing system. Experiment 1 demonstrated the other-race effect on audiovisual speech integration such that the infants ages 5–6 months and 8–9 months are likely to perceive the McGurk effect when observing an own-race-face speaker, but not when observing an other-race-face speaker. Experiment 2 found the other-race effect on audiovisual speech integration regardless of irrelevant speech identity cues. Experiment 3 confirmed the infants’ ability to differentiate two auditory syllables. These results showed that infants are likely to integrate voice with an own-race-face, but not with an other-race-face. This implies the role of experiences with own-race-faces in the development of audiovisual speech integration. Our findings also contribute to the discussion of whether perceptual narrowing is a modality-general, pan-sensory process.

Nociception and Pain: New Roles for Exosomes

The interchange of information from one cell to another relies on the release of hundreds of different molecules including small peptides, amino acids, nucleotides, RNA, steroids, retinoids, or fatty acid metabolites. Many of them are released to the extracellular matrix as free molecules and others can be part of the cargo of cellular vesicles. Small extracellular vesicles (30–150 nm), also known as exosomes, are a known mechanism of cell-to-cell communication in the nervous system. Exosomes participate in the pathogenesis of several neurological conditions including Alzheimer’s and Parkinson’s disease. However, exciting emerging evidence demonstrates that exosomes also regulate mechanisms of the sensory process including nociception. The goal of this review is to summarize the literature on exosome biogenesis, methods of small vesicle isolation and purification, and their role in nociception. We also provide insights on the potential applications of exosomes as pain biomarkers or as novel therapeutics.

A recurrent cortical model can parsimoniously explain the effect of expectations on sensory processes

The effect of prior knowledge and expectations on perceptual and decision-making processes have been extensively studied. Yet, the computational mechanisms underlying those effects have been a controversial issue. Recently, using a recursive Bayesian updating scheme, unmet expectations have been shown to entail further computations, and consequently delay perceptual processes. Here we take a step further and model these empirical findings with a recurrent cortical model, which was previously suggested to approximate Bayesian inference (Heeger, 2017). Our model fitting results show that the cortical model can successfully predict the behavioral effects of expectation. That is, when the actual sensory input does not match with the expectations, the sensory process needs to be completed with additional, and consequently longer, computations. We suggest that this process underlies the delay in perceptual thresholds in unmet expectations. Overall our findings demonstrate that a parsimonious recurrent cortical model can explain the effects of expectation on sensory processes.

Literary Translation and Transmediality: Clive Scott’s Reader-Oriented Translation Theory and Practice

The British translation practitioner and theorist Clive Scott has presented an approach to literary translation that integrates the transmedial into textual translation. His translations of poetry contain doodling, handwriting, crossing out, writing over, typographical experimentation, and photo-collages; he even offers photo-poetic translations consisting exclusively of photos. By including such extra-verbal matter, they play with the medium of literature and integrate a rich variety of visual forms. Scott wishes to stress the role of perception in translating; he offers a reader-focused theory of translation. He is much less concerned with translation as a service for people who do not understand the original language than with the act of translating as a school for reading and hence for developing our capacities of perception and self-awareness. The materiality of language plays a major role in such an idea of translation. His approach has little to do with intentional meaning, focusing instead on the accessibility of sense. Translating is a process, and it is the relationship of this process to what Scott rightly sees as the multi-sensory process of meaning-making during reading that is at issue in his theory and practice. By analysing Scott’s theory and examples of his translationwork, this paper considers what this approach to translating says about transmediality in a phenomenological sense: it sheds light on how we read and perceive and on what the transmedial elements in these processes do. Scott’s transmedial translation theory and practice bring to the fore the multiplicity of media involved in the perception of a text in the reader’s mind and thus sharpens the awareness of what language is and does.

Physical limits to sensing material properties

All materials respond heterogeneously at small scales, which limits what a sensor can learn. Although previous studies have characterized measurement noise arising from thermal fluctuations, the limits imposed by structural heterogeneity have remained unclear. In this paper, we find that the least fractional uncertainty with which a sensor can determine a material constant λ0 of an elastic medium is approximately $$\delta {\lambda }_{0}/{\lambda }_{0} \sim ({\Delta }_{\lambda }^{1/2}/{\lambda }_{0}){(d/a)}^{D/2}{(\xi /a)}^{D/2}$$ δ λ 0 / λ 0 ~ ( Δ λ 1 / 2 / λ 0 ) ( d / a ) D / 2 ( ξ / a ) D / 2 for a ≫ d ≫ ξ, $${\lambda }_{0}\gg {\Delta }_{\lambda }^{1/2}$$ λ 0 ≫ Δ λ 1 / 2 , and D > 1, where a is the size of the sensor, d is its spatial resolution, ξ is the correlation length of fluctuations in λ0, Δλ is the local variability of λ0, and D is the dimension of the medium. Our results reveal how one can construct devices capable of sensing near these limits, e.g. for medical diagnostics. We use our theoretical framework to estimate the limits of mechanosensing in a biopolymer network, a sensory process involved in cellular behavior, medical diagnostics, and material fabrication.

Perceptual Psychology: a Transcendental Perspective

Using the meta-empirical foundations of the transcendental approach to the study of perception, the author organizes and generalizes the theoretical and empirical data of modern foreign and domestic perceptual studies (about 1,000 sources) in the following areas: methodological and methodical aspects of the modern perceptual psychology; correlation of types of scientific rationality in the modern perceptual psychology; the process of perception as a special function of the psyche, etc. The paper identifies the core methodological and methodical trends in the development of the modern perceptual psychology: expanded requirements for the lack of bias, accuracy and reliability of experimental studies; ontologization of the research subject; complexity and crosscutting features of the research system; the active use of modern technological opportunities, including the renovation of classical research methods. The author substantiates the methodological necessity of a brand new resource for studying perception from the proper positions of meta-empirical foundations — a transcendental approach, in which the directly sensory process of perception is positioned as a process of form generation helping to distinguish the generative quality of this process and capture its diffe­rence from the structural qualities of other information processes. Against the modern trends in the positioning of perception as an auxiliary stage of latent representation and categorization of objects of the external world, the author shows the relevance and identifies the means of distinguishing perception as a special function of the psyche. The paper substantiates the transcendental type of scientific rationality, alternative to the epistemological paradigm of cognition.