Subtle morphological changes in the visual and antennal sensory system of bees and wasps across an urbanisation gradient.

Increased temperature and fragmentation of green spaces in urban areas could drive variations in functional traits of insects. Such morphological shifts may occur for sensory systems, which were previously reported to be prone to change with habitat characteristics in non-urban contexts. Here, we measured traits related to the visual and antennal sensory systems in the bees Halictus scabiosae and Osmia cornuta and the wasp Polistes dominula along an urbanisation gradient within Milan (Italy). We hypothesised that fragmentation could filter for better visual properties, and that higher temperature could filter for fewer thermoreceptors and more olfactory hairs. While controlling for body size, results show subtle but appreciable responses to urbanisation in one or more traits in all species, though not always supporting our hypotheses. O. cornuta shows marginally higher ommatidia density and smaller ommatidia diameter (associated with better visual resolution) in more fragmented sites, as well as marginally fewer thermoreceptors in hotter sites, in agreement with our two predictions. On the other hand, H. scabiosae has marginally smaller antennae and P. dominula has smaller eyes at warmer locations, and the wasp also has smaller antennae and 9th flagellomeres in more fragmented areas. Perhaps higher temperatures accelerate development of sensory system at higher speed than the rest of body in these two species. Our results represent the first evidence of urbanisation effects on the visual and antennal sensory systems of bees and wasps and underline how such effects may involve a much broader bouquet of traits then previously observed.

Neuromorphic antennal sensory system.

Insect antennae facilitate the nuanced detection of vibrations and deflections, and the non-contact perception of magnetic or chemical stimuli, capabilities not found in mammalian skin. Here, we report a neuromorphic antennal sensory system that emulates the structural, functional, and neuronal characteristics of ant antennae. Our system comprises electronic antennae sensor with three-dimensional flexible structures that detects tactile and magnetic stimuli. The integration of artificial synaptic devices adsorbed with solution-processable MoS2 nanoflakes enables synaptic processing of sensory information. By emulating the architecture of receptor-neuron pathway, our system realizes hardware-level, spatiotemporal perception of tactile contact, surface pattern, and magnetic field (detection limits: 1.3 mN, 50 µm, 9.4 mT). Vibrotactile-perception tasks involving profile and texture classifications were accomplished with high accuracy (> 90%), surpassing human performance in "blind" tactile explorations. Magneto-perception tasks including magnetic navigation and touchless interaction were successfully completed. Our work represents a milestone for neuromorphic sensory systems and biomimetic perceptual intelligence.

How larvae feel the world around them.

A complete map of the external sense organs shows how fruit fly larvae detect different aspects of their environment.

Distinct distribution of subplate neuron subtypes between the sensory cortices during the early postnatal period.

Subplate neurons (SpNs) are a heterogeneous neuronal population actively involved in early cortical circuit formation. In rodents, many SpNs survive and form layer 6b. The molecular heterogeneity of SpNs raises the question of whether different subpopulations of SpNs survive through the early postnatal period similarly and whether such diverse SpN populations in the auditory cortex (ACtx) share a common distribution pattern with other sensory systems. To address that, we investigated the expression pattern of multiple specific SpN markers in the ACtx, as well as in the visual (VCtx) and somatosensory (SCtx) cortices as controls, using complexin 3 (Cplx3) antibodies and different SpN-specific Cre-driver mice, such as connective tissue growth factor (CTGF), dopamine receptor D1 (Drd1a), and neurexophilin 4 (Nxph4). We focused on two early time windows in auditory development: (1) during the second postnatal week (PNW) before ear-canal opening and (2) during the third PNW after ear-canal opening. We compared the expression pattern of different SpN markers in ACtx with VCtx and SCtx. At both examined timepoints, Cplx3 and Nxph4 expressing SpNs form the largest and smallest population in the ACtx, respectively. Similar distribution patterns are observable in the VCtx and SCtx during the second PNW but not during the third PNW, for a higher proportion of Drd1a expressing SpNs is detected in the VCtx and CTGF expressing SpNs in the SCtx. This study suggests that different populations of SpNs might contribute differently to the development of individual sensory circuits.

Remodelling the inguinal adipose sensory system to switch on the furnace: Electroacupuncture stimulation induces brown adipose thermogenesis.

Brown and white adipose tissue mediate thermogenesis through the thermogenetic centre of the brain, but safe methods for activating thermogensis and knowledge of the associated molecular mechanisms are lacking. We investigated body surface electroacupuncture stimulation (ES) at ST25 (targeted at the abdomen) induction of brown adipose thermogenesis and the neural mechanism of this process. Inguinal white adipose tissue (iWAT) and interscapular brown adipose tissue (iBAT) were collected and the thermogenic protein expression levels were measured to evaluate iBAT thermogenesis capacity. The thermogenic centre activating region and sympathetic outflow were evaluated based on neural electrical activity and c-fos expression levels. iWAT sensory axon plasticity was analysed with whole-mount adipose tissue imaging. ES activated the sympathetic nerves in iBAT and the c-fos-positive cells induced sympathetic outflow activation to the iBAT from the medial preoptic area (MPA), the dorsomedial hypothalamus (DM) and the raphe pallidus nucleus (RPA). iWAT denervation mice exhibited decreased c-fos-positive cells in the DM and RPA, and lower recombinant uncoupling orotein 1 peroxisome proliferator-activated receptor, ß3-adrenergic receptor, and tyrosine hydroxylase expression. Remodelling the iWAT sensory axons recovered the signal from the MPA to the RPA and induced iBAT thermogenesis. The sympathetic denervation attenuated sensory nerve density. ES induced sympathetic outflow from the thermogenetic centres to iBAT, which mediated thermogenesis. iWAT sensory axon remodelling induced the MPA-DM-RPA-iBAT thermogenesis pathway.

Bionic artificial skin with a fully implantable wireless tactile sensory system for wound healing and restoring skin tactile function.

Tactile function is essential for human life as it enables us to recognize texture and respond to external stimuli, including potential threats with sharp objects that may result in punctures or lacerations. Severe skin damage caused by severe burns, skin cancer, chemical accidents, and industrial accidents damage the structure of the skin tissue as well as the nerve system, resulting in permanent tactile sensory dysfunction, which significantly impacts an individual's daily life. Here, we introduce a fully-implantable wireless powered tactile sensory system embedded artificial skin (WTSA), with stable operation, to restore permanently damaged tactile function and promote wound healing for regenerating severely damaged skin. The fabricated WTSA facilitates (i) replacement of severely damaged tactile sensory with broad biocompatibility, (ii) promoting of skin wound healing and regeneration through collagen and fibrin-based artificial skin (CFAS), and (iii) minimization of foreign body reaction via hydrogel coating on neural interface electrodes. Furthermore, the WTSA shows a stable operation as a sensory system as evidenced by the quantitative analysis of leg movement angle and electromyogram (EMG) signals in response to varying intensities of applied pressures.

The role of sensory systems in the association between balance and walking in people with multiple sclerosis.

BACKGROUND: In Multiple Sclerosis, it has been demonstrated that balance is related to performances in walking tasks at different levels of complexity. However, it is unknown how the different sensory systems involved in balance control contribute to walking. This observational study investigates the associations between somatosensory, vestibular, and visual systems and measures of self-reported walking and walking capacity at different complexity levels (i.e. low, medium, and high). METHODS: People with MS with EDSS<6 were assessed through the Sensory Organization Test (SOT), 12-Item MS Walking Scale (MSWS-12), Timed 25-Foot Walk (T25FW), Timed Up-and-Go Test (TUG), and Six-Spot-Step-Test (SSST). T25FW, TUG and SSST are measures of low, medium and high walking capacity, respectively. RESULTS: Forty-five PwMS were enrolled (EDSS: 3.4 ± 1.3). Capacity/ability walking measures were moderate-to-highly significantly associated (p < 0.01). Balance measures from SOT showed significant correlation (p < 0.05) between vestibular system and all the walking measures; between visual system and T25FW, SSST and MSWS-12; between the degree to which the patient relies on the visual system to maintain balance with conflicting visual surroundings information (VIS PREF) and T25FW and TUG. In the multivariate analyses, only VIS PREF significantly correlated (p < 0.05) with T25FW (std. Beta=0.42) and TUG (std. Beta=0.38). CONCLUSIONS: Vestibular and visual systems are associated with walking capacity. However, tasks with higher complexity levels require more visual attention towards ground obstacles, as often seen in real-life activities, whereas simpler walking tasks seem to require visual attention towards the surroundings.

Sequential maturation of stimulus-specific adaptation in the mouse lemniscal auditory system.

Stimulus-specific adaptation (SSA), the reduction of neural activity to a common stimulus that does not generalize to other, rare stimuli, is an essential property of our brain. Although well characterized in adults, it is still unknown how it develops during adolescence and what neuronal circuits are involved. Using in vivo electrophysiology and optogenetics in the lemniscal pathway of the mouse auditory system, we observed SSA to be stable from postnatal day 20 (P20) in the inferior colliculus, to develop until P30 in the auditory thalamus and even later in the primary auditory cortex (A1). We found this maturation process to be experience-dependent in A1 but not in thalamus and to be related to alterations in deep but not input layers of A1. We also identified corticothalamic projections to be implicated in thalamic SSA development. Together, our results reveal different circuits underlying the sequential SSA maturation and provide a unique perspective to understand predictive coding and surprise across sensory systems.

Mapping the avian visual tectofugal pathway using 3D reconstruction.

Image processing in amniotes is usually accomplished by the thalamofugal and/or tectofugal visual systems. In laterally eyed birds, the tectofugal system dominates with functions such as color and motion processing, spatial orientation, stimulus identification, and localization. This makes it a critical system for complex avian behavior. Here, the brains of chicks, Gallus gallus, were used to produce serial brain sections in either coronal, sagittal, or horizontal planes and stained with either Nissl and Gallyas silver myelin or Luxol fast blue stain and cresyl echt violet (CEV). The emerging techniques of diffusible iodine-based contrast-enhanced computed tomography (diceCT) coupled with serial histochemistry in three planes were used to generate a comprehensive three-dimensional (3D) model of the avian tectofugal visual system. This enabled the 3D reconstruction of tectofugal circuits, including the three primary neuronal projections. Specifically, major components of the system included four regions of the retina, layers of the optic tectum, subdivisions of the nucleus rotundus in the thalamus, the entopallium in the forebrain, and supplementary components connecting into or out of this major avian visual sensory system. The resulting 3D model enabled a better understanding of the structural components and connectivity of this complex system by providing a complete spatial organization that occupied several distinct brain regions. We demonstrate how pairing diceCT with traditional histochemistry is an effective means to improve the understanding of, and thereby should generate insights into, anatomical and functional properties of complicated neural pathways, and we recommend this approach to clarify enigmatic properties of these pathways.

Reduced Cortico-Cortical Resting-State Connectivity in Sensory Systems Related to Bodily Pain in Juvenile Fibromyalgia.

OBJECTIVE: Juvenile-onset fibromyalgia (JFM) is a paradigmatic chronic pain condition for which the underlying neurobiological substrates are poorly understood. This study examined, for the first time, data-driven resting-state functional connectivity (rsFC) alterations in 37 female adolescents with JFM compared with 43 healthy female adolescents and identified associations with bodily pain. METHODS: Whole-brain voxel-wise rsFC alterations were assessed using the intrinsic connectivity contrast, a measure of node centrality at each voxel, and seed-based analyses for interpretability. We studied the relationship between rsFC alterations in somatosensory systems and the location and extension of bodily pain. RESULTS: Adolescents with JFM had voxel-wise rsFC reductions in the paracentral lobule (PCL)/primary somatosensory cortex (S1) (T = 4.89, family-wise error corrected p-value (pFWE) < 0.001) and left midcingulate cortex (T = 4.67, pFWE = 0.043). Post hoc analyses revealed reduced rsFC spanning major cortical sensory hubs (T > 4.4, pFWE < 0.030). Cortico-cortical rsFC reductions within PCL/S1 in JFM occurred in locations innervated by bodily areas where the pain was most frequent (F = 3.15; positive false discovery rate = 0.029) and predicted widespread pain (T > 4.4, pFWE < 0.045). Conversely, adolescents with JFM had increases in PCL/S1-thalamus (T = 4.75, pFWE = 0.046) and PCL/S1-anterior insula rsFC (T = 5.13, pFWE = 0.039). CONCLUSION: Reduced cortico-cortical sensory integration involving PCL/S1 and spanning the sensory systems may underly critical pain sensory features in youth with JFM. Reduced sensory integration is paralleled by augmented cross-talk between sensory and affective/salience-processing regions, potentially indicating a shift toward more affectively colored sensory experiences to the detriment of specific sensory discrimination.

A nonneural miRNA cluster mediates hearing via repression of two neural targets.

We show here that mir-279/996 are absolutely essential for development and function of Johnston's organ (JO), the primary proprioceptive and auditory organ in Drosophila Their deletion results in highly aberrant cell fate determination, including loss of scolopale cells and ectopic neurons, and mutants are electrophysiologically deaf. In vivo activity sensors and mosaic analyses indicate that these seed-related miRNAs function autonomously to suppress neural fate in nonneuronal cells. Finally, genetic interactions pinpoint two neural targets (elav and insensible) that underlie miRNA mutant JO phenotypes. This work uncovers how critical post-transcriptional regulation of specific miRNA targets governs cell specification and function of the auditory system.

Neuroplastic changes in functional wiring in sensory cortices of the congenitally deaf: A network analysis.

Congenital sensory deprivation induces significant changes in the structural and functional organisation of the brain. These are well-characterised by cross-modal plasticity, in which deprived cortical areas are recruited to process information from non-affected sensory modalities, as well as by other neuroplastic alterations within regions dedicated to the remaining senses. Here, we analysed visual and auditory networks of congenitally deaf and hearing individuals during different visual tasks to assess changes in network community structure and connectivity patterns due to congenital deafness. In the hearing group, the nodes are clearly divided into three communities (visual, auditory and subcortical), whereas in the deaf group a fourth community consisting mainly of bilateral superior temporal sulcus and temporo-insular regions is present. Perhaps more importantly, the right lateral geniculate body, as well as bilateral thalamus and pulvinar joined the auditory community of the deaf. Moreover, there is stronger connectivity between bilateral thalamic and pulvinar and auditory areas in the deaf group, when compared to the hearing group. No differences were found in the number of connections of these nodes to visual areas. Our findings reveal substantial neuroplastic changes occurring within the auditory and visual networks caused by deafness, emphasising the dynamic nature of the sensory systems in response to congenital deafness. Specifically, these results indicate that in the deaf but not the hearing group, subcortical thalamic nuclei are highly connected to auditory areas during processing of visual information, suggesting that these relay areas may be responsible for rerouting visual information to the auditory cortex under congenital deafness.

Insect neurobiology: What to do with conflicting evidence?

Sensory systems gather information from the environment so the nervous system can formulate appropriate responses. But what happens when sensory information is inconsistent? A new study demonstrates how flies respond to incompatible visual evidence of their own motion.

Nanoporous MoS2 Field-Effect Transistor Based Artificial Olfaction: Achieving Enhanced Volatile Organic Compound Detection Inspired by the Drosophila Olfactory System.

Olfaction, a primal and effective sense, profoundly impacts our emotions and instincts. This sensory system plays a crucial role in detecting volatile organic compounds (VOCs) and realizing the chemical environment. Animals possess superior olfactory systems compared to humans. Thus, taking inspiration from nature, artificial olfaction aims to achieve a similar level of excellence in VOC detection. In this study, we present the development of an artificial olfaction sensor utilizing a nanostructured bio-field-effect transistor (bio-FET) based on transition metal dichalcogenides and the Drosophila odor-binding protein LUSH. To create an effective sensing platform, we prepared a hexagonal nanoporous structure of molybdenum disulfide (MoS2) using block copolymer lithography and selective etching techniques. This structure provides plenty of active sites for the integration of the LUSH protein, enabling enhanced binding with ethanol (EtOH) for detection purposes. The coupling of the biomolecule with EtOH influences the bio-FETs potential, which generates indicative electrical signals. By mimicking the sniffing techniques observed in Drosophila, these bio-FETs exhibit an impressive limit of detection of 10-6% for EtOH, with high selectivity, sensitivity, and detection ability even in realistic environments. This bioelectric sensor demonstrates substantial potential in the field of artificial olfaction, offering advancements in VOC detection.

Zinc oxide nanoparticles disrupt development and function of the olfactory sensory system impairing olfaction-mediated behaviour in zebrafish.

Zinc (Zn) is an essential metal present in numerous enzymes throughout the body, playing a vital role in animal and human health. However, the increasing use of zinc oxide nanomaterials (ZnONPs) in a diverse range of products has raised concerns regarding their potential impacts on health and the environment. Despite these concerns, the toxicity of ZnONP exposure on animal health remain poorly understood. To help address this knowledge gap, we have developed a highly sensitive oxidative stress (OS) biosensor zebrafish capable of detecting cell/tissue-specific OS responses to low doses of various oxidative stressors, including Zn, in a live fish embryo. Using live-imaging analysis with this biosensor zebrafish embryo, we discovered that the olfactory sensory neurons in the brain are especially sensitive to ZnOP exposure. Furthermore, through studies monitoring neutrophil migration and neuronal activation in the embryonic brain and via behaviour analysis, we have found that sub-lethal doses of ZnONPs (ranging from 0.033 to 1 mg/L nominal concentrations), which had no visible effect on embryo growth or morphology, cause significant localised inflammation, disrupting the neurophysiology of olfactory brain tissues and ultimately impaired olfaction-mediated behaviour. Collectively, these findings establish a potent and important effect mechanism for ZnONP toxicity, indicating the olfactory sensory system as the primary target for ZnONPs as an environmental toxicant in aquatic environments. Our result also highlights that even low doses of ZnONPs can have detrimental effects on the olfactory sensory system, surpassing previous expectations. The importance of olfaction in environment sensing, sex behaviours and overall fitness across species raises concerns about the potential impact of ZnONPs on olfaction-mediated brain function and behaviour in animals and humans. Our study emphasises the need for greater consideration of the potential risks associated with these nanomaterials.

Feedforward attentional selection in sensory cortex.

Salient objects grab attention because they stand out from their surroundings. Whether this phenomenon is accomplished by bottom-up sensory processing or requires top-down guidance is debated. We tested these alternative hypotheses by measuring how early and in which cortical layer(s) neural spiking distinguished a target from a distractor. We measured synaptic and spiking activity across cortical columns in mid-level area V4 of male macaque monkeys performing visual search for a color singleton. A neural signature of attentional capture was observed in the earliest response in the input layer 4. The magnitude of this response predicted response time and accuracy. Errant behavior followed errant selection. Because this response preceded top-down influences and arose in the cortical layer not targeted by top-down connections, these findings demonstrate that feedforward activation of sensory cortex can underlie attentional priority.

Sensory cortex plasticity supports auditory social learning.

Social learning (SL) through experience with conspecifics can facilitate the acquisition of many behaviors. Thus, when Mongolian gerbils are exposed to a demonstrator performing an auditory discrimination task, their subsequent task acquisition is facilitated, even in the absence of visual cues. Here, we show that transient inactivation of auditory cortex (AC) during exposure caused a significant delay in task acquisition during the subsequent practice phase, suggesting that AC activity is necessary for SL. Moreover, social exposure induced an improvement in AC neuron sensitivity to auditory task cues. The magnitude of neural change during exposure correlated with task acquisition during practice. In contrast, exposure to only auditory task cues led to poorer neurometric and behavioral outcomes. Finally, social information during exposure was encoded in the AC of observer animals. Together, our results suggest that auditory SL is supported by AC neuron plasticity occurring during social exposure and prior to behavioral performance.

Active smelling in the American cockroach.

Motion plays an essential role in sensory acquisition. From changing the position in which information can be acquired to fine-scale probing and active sensing, animals actively control the way they interact with the environment. In olfaction, movement impacts the time and location of odour sampling as well as the flow of odour molecules around the olfactory organs. Employing a detailed spatiotemporal analysis, we investigated how insect antennae interact with the olfactory environment in a species with a well-studied olfactory system - the American cockroach. Cockroaches were tested in a wind-tunnel setup during the presentation of odours with different attractivity levels: colony extract, butanol and linalool. Our analysis revealed significant changes in antennal kinematics when odours were presented, including a shift towards the stream position, an increase in vertical movement and high-frequency local oscillations. Nevertheless, the antennal shifting occurred predominantly in a single antenna while the overall range covered by both antennae was maintained throughout. These findings hold true for both static and moving stimuli and were more pronounced for attractive odours. Furthermore, we found that upon odour encounter, there was an increase in the occurrence of high-frequency antennal sweeps and vertical strokes, which were shown to impact the olfactory environment's statistics directly. Our study lays out a tractable system for exploring the tight coupling between sensing and movement, in which antennal sweeps, in parallel to mammalian sniffing, are actively involved in facilitating odour capture and transport, generating odour intermittency in environments with low air movement where cockroaches dwell.

Generation of Meaty Aroma from Onion (Allium cepa L.) with Polyporus umbellatus: Fermentation System, Sensory Profile, and Aroma Characterization.

One of the main reasons for consumer rejection of plant-based meat alternatives is the lack of meaty flavor after cooking. In this study, a platform was developed to generate meaty flavors solely from Allium substrates (chives, leeks, ramsons, and onions) using basidiomycete-mediated submerged fermentations. Polyporus umbellatus-mediated fermentation of onions resulted in an intense meaty and liver sausage-like flavor under proper fermentation parameters. Using multisolvent and solvent-free aroma extractions coupled with gas chromatography-mass spectrometry-olfactometry, 5 odorants with high assigned flavor dilution (FD) factors (≥ 256) were identified in the fermented sample that have been reported in the literature as important aroma compounds of meat products: methyl palmitate, bis(2-methyl-furyl) disulfide, (E,E)-2,4-decadienal, γ-nonalactone, and eugenol. Using selected ion monitoring, the presence of bis(2-methyl-furyl) disulfide (meaty, savory, FD 256) after fermentation was confirmed. It was proposed that P. umbellatus enzymatically forms bis(2-methyl-furyl) disulfide from intermediates derived from the thermal degradation of thiamine.

Dual-sensory fusion self-powered triboelectric taste-sensing system towards effective and low-cost liquid identification.

Infusing human taste perception into smart sensing devices to mimic the processing ability of gustatory organs to perceive liquid substances remains challenging. Here we developed a self-powered droplet-tasting sensor system based on the dynamic morphological changes of droplets and liquid-solid contact electrification. The sensor system has achieved accuracies of liquid recognition higher than 90% in five different applications by combining triboelectric fingerprint signals and deep learning. Furthermore, an image sensor is integrated to extract the visual features of liquids, and the recognition capability of the liquid-sensing system is improved to up to 96.0%. The design of this dual-sensory fusion self-powered liquid-sensing system, along with the droplet-tasting sensor that can autonomously generate triboelectric signals, provides a promising technological approach for the development of effective and low-cost liquid sensing for liquid food safety identification and management.