Complex Sensory Systems Research Articles

Specialized ovipositor sensilla of Cretaceous wasps (Insecta: Hymenoptera) possibly reveal a unique way of host detection.

Insects have evolved complex sensory systems that are important for feeding, defence and reproduction. Parasitoid wasps often spend much time and effort in searching for concealed hosts with the help of specialized sensilla. However, the early evolution of such behaviour and sensilla is poorly known. We describe two fossil female wasps, †Tichostephanus kachinensis sp. nov. and †Tichostephanus longus sp. nov., from mid-Cretaceous Kachin amber. Phylogenetic analyses based on morphological data retrieved †Tichostephanus as deeply nested within Evanioidea and closely related to extant Gasteruptiidae and Evaniidae. Both of these Cretaceous wasps possess features, e.g. coronal tubercles and flexible ovipositor sheaths, that indicate that they might have laid eggs in wood where their larvae possibly parasitized insect larvae. They have a peculiar and unique 'bottle brush' of sensilla close to the apex of their ovipositor sheaths, which has not been observed in any extant parasitoid wasps. These sensilla comprise many regularly arranged plate-shaped setae, attached in relatively large sockets and with rows of longitudinal ridges. Such specialized sensilla perhaps served to enhance the ability to detect hosts inside wood.

Functional dissection of phytochrome A in plants.

Plants lack behavioral responses to avoid dramatic environmental changes associated with the annual seasons. For survival, they have evolved complex sensory systems to sense fluctuations in light and optimize their architecture in response to changes in these cues. Phytochrome A (phyA) was initially identified as a photoreceptor that senses far-red light signals. It was then identified as playing a central role in promoting hypocotyl growth, fiber development, and flowering time in a variety of plants including Arabidopsis, rice, soybean and cotton. Under dark conditions, phyA is present in the cytoplasm in the physiologically inactive (Pr) form. Far-red light signals induce the transformation of Pr into the physiologically active (Pfr) form, after which Pfr-phyA is recognized by FAR-RED ELONGATED HYPOCOTYL 1 (FHY1) and FHY1-LIKE (FHL) and translocated to the nucleus, initiating a series of signaling cascades. The current review comprehensively summarizes recent advances in understanding the function of phyA in plants, including phyA-mediated shade avoidance and flowering time. Remaining issues and possible directions for future research on phyA are also discussed.

Process Modelling and Creating Predictive Models of Sensory Networks Using Fuzzy Petri Nets

The current period is evidence of the massive replacement of human power with the results of the mental cognitive work of researchers. This mainly concerns the area of industrial production, where the aim is to apply new technologies on the principle of artificial intelligence, using the possibilities of a new direction in the use of a technology called the Internet of Things (IoT). With this idea, however, the question of the user disappears, who in this chaos of massive information can get into a state, where his activities will no longer be manageable. To cope with this situation, it is necessary to examine the impact of these technologies on the quality of life in the work and home environment. This paper investigates process modelling and the creation of predictive models to obtain the emotional state of users. The created predictive models will later allow the simulation of complex sensory systems, which will be able to predict the emotional states of users based on their physiological states. The aim is to also find connections between physiological states and basic emotions to be able to classify user emotions with the highest possible accuracy in the classification process.

Multiple complex somatosensory systems in mature rat molars defined by immunohistochemistry

ObjectiveIntradental sensory receptors trigger painful sensations and unperceived mechanosensitivity, but the receptor bases for those functions are only partly defined. We present new evidence here concerning complex endings of myelinated axons in rat molars. DesignWe sectioned mature rat jaws in sagittal and transverse planes to analyze neural immunoreactivity (IR) for parvalbumin, peripherin, neurofilament protein, neurotrophin receptors, synaptophysin, calcitonin gene-related peptide (CGRP), or mas-related g-protein-receptor-d (Mrgprd). ResultsWe found two complex sensory systems in mature rat molar dentin that labeled with neurofilament protein-IR, plus either parvalbumin-IR or peripherin-IR. The parvalbumin-IR system made extensively branched, beaded endings focused into dentin throughout each pulp horn. The peripherin-IR system primarily made unbeaded, fork-shaped dentinal endings scattered throughout crown including cervical regions. Both of these systems differed from neuropeptide CGRP-IR. In molar pulp we found peripherin- and parvalbumin-IR layered endings, either near special horizontal plexus arrays or in small coiled endings near tangled plexus, each with specific foci for specific pulp horns. Parvalbumin-IR nerve fibers had Aβ axons (5–7μm diameter), while peripherin-IR axons were thinner Aδ size (2–5μm). Mechano-nociceptive Mrgprd-IR was only found in peripherin-IR axons. ConclusionsComplex somatosensory receptors in rat molars include two types of dentinal endings that both differ from CGRP-IR endings, and at least two newly defined types of pulpal endings. The PV-IR neurons with their widely branched, synaptophysin-rich, intradentinal beaded endings are good candidates for endodontic non-nociceptive, low threshold, unperceived mechanoreceptors. The complex molar dentinal and pulpal sensory systems were not found in rat incisors.

Multimodal sensorimotor system in unicellular zoospores of a fungus.

Complex sensory systems often underlie critical behaviors, including avoiding predators and locating prey, mates and shelter. Multisensory systems that control motor behavior even appear in unicellular eukaryotes, such as Chlamydomonas, which are important laboratory models for sensory biology. However, we know of no unicellular opisthokonts that control motor behavior using a multimodal sensory system. Therefore, existing single-celled models for multimodal sensorimotor integration are very distantly related to animals. Here, we describe a multisensory system that controls the motor function of unicellular fungal zoospores. We found that zoospores of Allomyces arbusculus exhibit both phototaxis and chemotaxis. Furthermore, we report that closely related Allomyces species respond to either the chemical or the light stimuli presented in this study, not both, and likely do not share this multisensory system. This diversity of sensory systems within Allomyces provides a rare example of a comparative framework that can be used to examine the evolution of sensory systems following the gain/loss of available sensory modalities. The tractability of Allomyces and related fungi as laboratory organisms will facilitate detailed mechanistic investigations into the genetic underpinnings of novel photosensory systems, and how multisensory systems may have functioned in early opisthokonts before multicellularity allowed for the evolution of specialized cell types.

Conserved roles ofems/Emxandotd/Otxgenes in olfactory and visual system development inDrosophilaand mouse

The regional specialization of brain function has been well documented in the mouse and fruitfly. The expression of regulatory factors in specific regions of the brain during development suggests that they function to establish or maintain this specialization. Here, we focus on two such factors—the Drosophila cephalic gap genes empty spiracles (ems) and orthodenticle (otd), and their vertebrate homologues Emx1/2 and Otx1/2—and review novel insight into their multiple crucial roles in the formation of complex sensory systems. While the early requirement of these genes in specification of the neuroectoderm has been discussed previously, here we consider more recent studies that elucidate the later functions of these genes in sensory system formation in vertebrates and invertebrates. These new studies show that the ems and Emx genes in both flies and mice are essential for the development of the peripheral and central neurons of their respective olfactory systems. Moreover, they demonstrate that the otd and Otx genes in both flies and mice are essential for the development of the peripheral and central neurons of their respective visual systems. Based on these recent experimental findings, we discuss the possibility that the olfactory and visual systems of flies and mice share a common evolutionary origin, in that the conserved visual and olfactory circuit elements derive from conserved domains of otd/Otx and ems/Emx action in the urbilaterian ancestor.

On Volume Based 3D Display Techniques

In the case of certain applications in which a need exists to visualize and interact with voluminous data sets and complex 3-D geometrical models, the conventional computer interface inhibits key human-computer interaction processes. Here, several deficiencies of the standard interface are identified with emphasis on a failure to make optimal use of the complex human sensory systems. Various general forms of interaction modality are outlined together with several types of image space. This provides a basis for brief discussion of emerging ‘creative’ 3-D display systems with emphasis on computational holography, varifocal techniques, and volumetric systems.

First-Rank Symptoms in Schizophrenia: Reexamining Mechanisms of Self-recognition

Disturbances of self are a common feature of schizophrenic psychopathology, with patients reporting that their thoughts and actions are controlled by external forces, as shown in first-rank symptoms (FRS). One widely accepted explanatory model of FRS suggests a deficiency in the internal forward model system. Recent studies in the field of cognitive sciences, however, have generated new insights into how complex sensory and motor systems contribute to the sense of self-recognition, and it is becoming clear that the forward model conceptualization does not have unique access to representations about the self. We briefly evaluate the forward model explanation of FRS, reassess the distinction made between the sense of agency and body ownership, and outline recent developments in 4 domains of sensory-motor control that have supplemented our understanding of the processes underlying the sense of self-recognition. The application of these findings to FRS will open up new research directions into the processes underlying these symptoms.

The surprisingly diverse ways that prokaryotes move

Prokaryotic cells move through liquids or over moist surfaces by swimming, swarming, gliding, twitching or floating. An impressive diversity of motility mechanisms has evolved in prokaryotes. Movement can involve surface appendages, such as flagella that spin, pili that pull and Mycoplasma 'legs' that walk. Internal structures, such as the cytoskeleton and gas vesicles, are involved in some types of motility, whereas the mechanisms of some other types of movement remain mysterious. Regardless of the type of motility machinery that is employed, most motile microorganisms use complex sensory systems to control their movements in response to stimuli, which allows them to migrate to optimal environments.

Estimulación magnética transcraneal: aportaciones al estudio de la vía visual

Most of our impressions of the world and our memory are based on sight. Being able to look around us and recognise our surroundings involves the activity of several processing pathways in the brain that interact with each other and integrate information until it becomes conscious. Little is known about all these mechanisms today and therefore new tools must be developed and employed to enable us to further our understanding in this field. The visual system is one of the most complex sensory systems. An important part of what we do know about how it is organised derives from studies carried out in animals or from clinical findings in patients with visual problems caused by local lesions. In recent years, advances in neurophysiological recording and stimulation techniques have made it possible to study visual functioning in a far more direct manner. Transcranial magnetic stimulation (TMS) is one of these new techniques and can be used to assess the excitability of the occipital cortex, induce conscious visual perceptions, produce 'virtual lesions' and even carry out direct manipulation of several visuoperceptual tasks. In this work we present the main applications of TMS in the study of the visual pathway, its most significant technical aspects and its clinical usefulness from the diagnostic point of view and within the field of visual rehabilitation. TMS is a safe technique with important clinical and therapeutic implications, which offers valuable data about the mechanisms underlying the processing of visual information, and it is therefore becoming a very useful tool within the areas of neuroscience and clinical neurology.

Sea Urchin Genome Confirms Kinship to Humans and Other Vertebrates

GENETICSIn a special section beginning on page [938][1] of this week's issue of Science , researchers describe the 814 million DNA bases that make up the genome of the purple sea urchin, Strongylocentrotus purpuratus . Its 23,500 genes suggest that these algae-eating invertebrates have more complex immune and sensory systems than researchers had appreciated. ([Read more][2].) [1]: http://www.sciencemag.org/cgi/content/short/314/5801/938 [2]: http://www.sciencemag.org/cgi/content/full/314/5801/908

An “eye” in the gut: the appendix as a sentinel sensory organ of the immune intelligence network

Neural systems are the traditional model of intelligence. Their complex interconnected network of wired neurons acquires, processes, and responds to environmental cues. We propose that the immune system is a parallel system of intelligence in which the gut, including the appendix, plays a prominent role in data acquisition. The immune system is essentially a virtual unwired network of interacting cells that acquires, processes, and responds to environmental data. The data is typically acquired by antigen-presenting cells (APCs) that gather antigenic information from the environment. The APCs chemically digest large antigens and deconstruct them into smaller data packets for sampling by other cells. The gut performs the same function on a larger scale. Morsels of environmental content that enter the gut are sequentially deconstructed by physical and chemical digestion. In addition to providing nutrients, the componentized contents offer environmental data to APCs in mucosa-associated lymphoid tissues (MALT) that relay the sampled information to the immune intelligence network. In this framework, positioning of the appendix immediately after the ileocecal valve is strategic: it is ideally positioned to sample environmental data in its maximally deconstructed state after small bowel digestion. For single-celled organisms, digestion of the environment has been the primary way to sample the surroundings. Prior to the emergence of complex sensory systems such as the eye, even multi-cellular organisms may have relied heavily on digestion to acquire environmental information. While the relative value of immune intelligence has diminished since the emergence of neural intelligence, organisms still use information from both systems in integrated fashion to respond appropriately to ecologic opportunities and challenges. Appendicitis may represent a momentary maladaptation in the evolutionary transition of sensory leadership from the gut to the eye. Relationships between immune dysfunctions and cognition are explored.

The evolution of mate choice and the potential for conflict between species and mate–quality recognition

Understanding how individuals select mates becomes complex when high-quality conspecifics resemble heterospecifics. Individuals facing such a situation may be unable to effectively identify both conspecifics (species recognition) and high-quality mates that can confer fitness benefits to the choosy individual or its offspring (mate-quality recognition). Here I suggest when a conflict may occur between species and mate-quality recognition, discuss the evolutionary consequences stemming from this conflict, and present a model of mate-preference evolution in response to heterospecifics. Determining how species and mate-quality recognition interact to shape mate-choice decisions is important for understanding the diversification of sexually selected traits among closely related taxonomic groups, the use of complex sensory systems for detecting mates, and seemingly inappropriate mate-choice decisions.

Parasite infection alters schooling behaviour: deviant positioning of helminth-infected minnows in conspecific groups

The formation of polarized swimming groups is a successful antipredator adaptation of many fish species because the confusion created by multiple synchronously moving targets reduces the attack success of predators. However, maintaining synchrony and spatial position within such groups requires the functioning of complex sensory and motor systems, so the ability to school effectively could be sensitive to disease or infection with debilitating parasites. As many predators overcome this confusion by attacking visually distinct individuals in groups, infection-associated traits that impair schooling ability might increase predation on parasitized school members, with consequences for the survival of both host and parasite. We report here on a study designed to investigate the effects of parasite infection on the schooling behaviour of European minnows, Phoxinus phoxinus. Over a series of trials done in a flow-pool, minnows infected with plerocercoid larvae of the cestode Ligula intestinalis consistently exhibited increased nearest neighbour distances when compared with uninfected conspecifics in the same school, suggesting that infected fish may be unable to maintain close spatial positions within schools. Positive relations were found between the area covered by a school and both the nearest neighbour differences of uninfected and infected fish in the school, but these relations differed with infected fish exhibiting increasingly larger nearest neighbour differences than uninfected fish as schools became more dispersed. Infected fish also occupied peripheral positions more often than would have been expected if individuals assorted randomly within schools. Our results indicate that infected fish in schools exhibit positioning behaviour that deviates from that of uninfected conspecifics. As schooling is known to be a primary antipredator response of minnows, the altered behaviour of parasitized individuals within polarized groups could increase their susceptibility to certain predators, with potential consequences for parasite transmission.

The evolution of complex sensory systems in mammals.

Much of the forebrain of many extant species of mammals appears to be sensory-perceptual in nature. Thus, much of the forebrain, especially the dorsal thalamus and neocortex, consists of nuclei and areas that are parts of complex systems that analyze sensory information and allow behavior to be guided by accurate inferences about the external world. Since mammals vary tremendously in brain size, they vary in the amount of tissue devoted to sensory processing. In addition, mammals vary in the sizes and numbers of processing nuclei and areas, and in how neurons and neuron groups (modules) are differentiated within such structures. Sensory-perceptual systems with more, larger and more differentiated parts may allow more stimulus parameters to be considered, experience to play a greater role, and speed calculations through increased parallel processing. The evolution of species differences in brain size, the sizes of individual parts, and internal structure of these parts are potentially understandable within a theoretical framework of gradual modifications of developmental processes. In addition to changes in the generation and specialization of neurons, alterations in the developmental timing that modify internal and external influences on neuron activity patterns seem to have a major role in the construction and maintenance of organization in the nervous system. Because similar selection pressures may arise over and over again and the mechanisms for producing changes may be few, similar changes in the nervous system are likely to occur in independent lines of evolution. It is uncertain how new cortical areas and nuclei evolve. Comparative studies suggest that: (1) all mammals have a few basic sensory areas and nuclei in common, (2) the number of areas and nuclei has increased independently in several lines of mammalian evolution, and (3) new areas have been added to the middle levels of cortical processing sequences. New areas and nuclei may have evolved as a result of sudden duplications and/or by the process of single areas or nuclei gradually differentiating into two or more areas or nuclei. The process of gradual differentiation may have involved the initial step of differentiating functionally distinct classes of cells that are mixed in a representation, followed by the local groupings of such cells into functionally distinct sets, and finally the fusion of cell groups of the same types to form separate representations.