Ronald R. Hoy - US grants

The goal of this project is to investigate the neurobehavioral mechanisms of acoustic communication, particularly species-specific signal recognition as it pertains to the identification of potential mates, rivals, and predators. Because of the relative simplicity of its acoustic behavior and auditory pathways in the CNS, the cricket is an ideal model system for investigating the problems of auditory physiology that are encountered by any animal that must rely upon auditory signals for communication. These include: (1) how crickets discriminate the mating calls of their own species from those of others-and how the auditory system detects differences in the temporal pattern of mating calls; (2) how crickets (and their auditory systems) discriminates the auditory signals of crickets from those of predators, such as bats; and (3) how the auditory system is hierarchically organized to recognize species-specific signals and how this input is translated into output: adaptive behavioral acts such as phonotaxis. An important advantage of crickets for these aspects of auditory research is that questions (1) - (3) may be studied neurophysiologically and anatomically at the level of a definable network of single, identified neurons. Thus, a cellular analysis of acoustic communication can be combined with previous studies at the behavioral, genetic, and evolutionary levels of organization. The cricket auditory system is also ideal for the study of certain kinds of developmental questions. For example, how does the auditory system respond to loss of an ear? We have found that the effects of deafferentation on the auditory system can be studied in the compensatory growth responses of single, identified interneurons. The compensatory growth of dendrites restores some measure of audition. These studies may provide a convenient cellular model for studying issues of developmental plasticity such as specificity in synaptogenesis, synaptic competition, and sensory regeneration.

One goal of this project is to investigate the neurobehavioral mechanisms of acoustic communication, particularly species-specific acoustic signals from potential mates or potential predators. Because of the relative simplicity of its auditory behavior and neural pathways in the CNS (compared to vertebrates), the cricket is an ideal model system for investigating the processing of auditory information into adaptive behavioral acts. Our research is directed at such questions as: (1) is auditory behavior under the control of single neurons, such as feature detectors or command neurons? (2) how does the animals's behavioral context determine the specific role that an auditory neuron plays in influencing particular auditory behaviors? (3) how is the auditory system organized to recognize the temporal pattern of species-specific mating calls, or to recognize the hunting calls of vocal predators (like bats)? (4) what is the role of courtship songs in mating behavior, and how are they processed in the auditory system? We hope to achieve a cellular analysis of auditory communication that can be combined with previous studies at the behavioral, genetic, and evolutionary levels of organization. The cricket auditory system is also ideal for the investigation of developmental questions. For example, how does the auditory system respond to the loss of an ear? The effects of auditory deprivation or deafferentiation can be studied in the level of single, identified neurons. 1) As in the case in other sensory systems, if the auditory nerve is sectioned, its axons can regenerate and restore function. 2) More unusually, compensatory growth in dendrites of sensory interneurons also restores auditory function. Does functional recovery involve synaptic competition for afferents among compensatory dendrites? Does the auditory afferent projection innervate ectopic dendritic projections by adding new terminal branches (and more synaptic space)? The auditory system of the cricket provides a system in which to study issues of synaptic plasticity such as dendritic and axonal sprouting, competition, and regeneration, at a cellular level through the analysis of single, identified neurons.

This award provides funds to the Department of Neurobiology and Behavior at Cornell University to help purchase equipment which will be used to teach undergraduate biology students, and students in allied fields such as physics, engineering and computer sciences, modern techniques in cellular neuroscience through hands- on laboratory experience. This will be accomplished by active research scientists in a series of three undergraduate courses entitled: 1) Principles of Neurophysiology, 2) Electronics for Neurobiologists, and 3) Computer Interfacing for Neurobiologists. In the first course, undergraduates will use the state-of-the-art research equipment (computers, voltage clamp amplifiers, micromanipulators, microelectrode pullers, and perfusion pumps) in laboratory exercises designed to teach the principles of electrical signalling in the nervous system. In these exercises, computer data acquisition and analysis and teaching students the use of Macintosh II computers, along with the related hardware and software necessary for this purpose will be emphasized. This course will replace all standard vertebrate preparations with invertebrate model systems. In the electronics course, students will learn fundamental principles of electronics as applied to electrophysiology and other biological fields to design simple, relevant circuits such as those used for basic voltage and patch clamp amplifiers. The computer interfacing course will use the Macintosh II computers to teach the technical details (hardware and software) of computer interfacing methods in biological experiments. This project has important significance not only in providing undergraduates with training in new and powerful methods of experimental neuroscience, but also in developing advanced teaching tools useful for other neuroscience training programs. Through this project, undergraduate students will gain theoretical and technical skills that will help them be productive scientists in both corporate and academic research environments. The grantee is matching this award with non-Federal sources.

This is a proposal to seek funding for participants of the Third International Congress of Neuroethology, to be held in Montreal Canada, August 9-14, 1992 on the campus of McGill University. The Congress has been held every two years. The first was in Japan and the second in Germany; this is the first in North America. The importance of this meeting is that it will allow significant numbers of American researchers (especially younger ones) in neuroethology, biobehavioral sciences, and biopsychology to become familiar with the important work in neuroethology of European, and to a lesser extent, Japanese workers. Neuroethology is a vigorous and important field in behavioral research in Germany and Britain, and it is growing in importance in the U.S.A. This is the first opportunity for significant numbers of North Americans (U.S., Canadians, Latin Americans) to attend the ICN, and the Steering Committee wants to be able to encourage participation by younger people. A special effort has been made by the Steering Committee to include women and minorities among the symposium speakers, and to mix them with the major leaders from Europe.

DESCRIPTION (provided by applicant): Our goal is to understand the basic principles behind the bioacoustical and neurobehavioral bases of hearing and communication in insects, especially sound localization in the fly, Ormia ochracea Bloengineers are applying design principles we learned from Ormia to construct tiny, silicon-based directional microphones for hearing aids, a strategy known as "biomimicry." This has stimulated us to consider how the fly's ears perform acoustically under noisy conditions. The ears' design features, forged over evolutionary time, include enhanced signal-to-noise and directional sensitivity while maintaining high sensitivity. In Ormia. both biomechanical and neural systems possess innovative auditory adaptations for temporal processing that are worth investigating for their intrinsic interest, and that have implications for practical applications, as well.We propose a set of behavioral experiments using a new apparatus to measure: (1) The ability of masking noise to degrade phonotaxis; (2) The ability to discriminate front from back sound sources; (3) How elevational cues are used to localize sound; and (4) Whether Ormia has an ultrasound-initiated ultrasound startle response. We propose a set of neurophysiological studies in Ormia's auditory system to determine: (1) Directional properties of auditory interneurons in the CNS; (2) The role of neural inhibition in shaping the directional responses in auditory interneurons; (3) How directional information in auditory pathways is integrated with flight-related propnoceptive signals to produce coordinated movements which steer the fly toward a sound source; (4) Mechanisms of multi-modal integration in the brain: when auditory and visual signals are present in cooperation or in rivalry.We propose to investigate the substrate communication system of Salticid jumping spiders. These spiders are renowned for their extravagant visual displays which turn out to be perfectly coordinated with a newly-discovered set of acoustic signals. The courtship behavior of these spiders will be an ideal system for the neuroethological study of multi-modal communication.

This proposal is a request for an ADAMHA Research Scientist Award (RSA). The research will focus on the investigation of neurobehavioral mechanisms that underlie auditory function and communication in crickets and flies because these insects can serve as model systems for understanding sensory processing and communication in higher animals. A major project involves the acoustic startle response (ASR) of crickets, which has numerous parallels to the ASR of mammals. The cricket's ASR exhibits several types of behavioral plasticity, including habituation, sensitization, and precedence effect, and the possibility that plasticity is under neuromodulatory control by biogenic amines will be investigated. In insects, acoustic behavior is mediated by many diverse mechanisms of sound production and a variety of hearing organs (ears), which are distributed among well-defined taxonomic lineages. Thus, it becomes possible to correlate the process by which identified neural changes occur with the pattern of acoustic behavior that evolved within insects. Thus, mechanistic physiological studies can be linked to an investigation of how behavioral adaptations evolve, a key first step in an evolutionary neuroethological approach to the study of behavior. The P.I. plans to continue his science education and mentoring activities through his involvement with the Grass Foundation, the Laboratory of Ornithology, and Bennington College. Other activities will include the development of laboratory teaching modules for undergraduate neuroscience, science enrichment through the introduction of bioacoustic teaching materials in grades K-12, and involvement with the Ithaca Science Center.

Neurobiology is an emerging interdisciplinary study that attracts world-wide attention in popular media. There is genuine curiosity abroad to understand the dynamic linkage between one's brain and one's behavior that should be part of the education, of not only scientists, but the lay public. Yet the teaching of neurobiology, especially in a laboratory setting, has badly lagged the demand. In part, this is because of the lack of availability of "teacher friendly" instructional exercises as well as easy availability of ethically and environmentally acceptable experimental animals. This project addresses these problems by providing teachers of physiology, neuroscience, and introductory biology, at the college and the high school level, with a new curriculum of laboratory exercises in neuroscience. We are teaching teachers how to use these exercises in their own labs by: (1) conducting a series of summer workshops in our teaching laboratory at Cornell; (2) producing an instructional videotape of our teaching exercises, aimed at teachers; and (3) setting-up an electronic bulletin-board service that permits us to stay in close contact with any teacher who is using or wants to use our teaching modules in his/her own laboratory instruction. Our teaching labs are based on an integrated set of classroom-tested labs that use the crayfish as the experimental animal. The crayfish is ideal because it is very hardy and easy to dissect. In terms of laboratory logistics, it is cheap, commercial, and easy to maintain. Pedagogically, the crayfish is ideal because it permits the instructor to select from simple lab exercises dealing with fundamental cellular properties of neural tissue to intellectually stimulating and challenging exercises that deal with the integrative properties of neural networks, synaptic computations, and learning and memory. These teaching modules thus cover basic neuronal properties, such as the ionic basis of bioelectric potentials to synaptic transfusion to elementary forms of learning and synaptic plasticity. They take advantage of the fact of the unity of neural function, the neuronal computations that lead to behavioral change are similar, whether occurring in the brain of a crayfish or a college freshman. The crayfish is therefore a suitable replacement for vertebrate preparations, which are becoming controversial as laboratory subjects. This project not only provides teachers with a set of conceptually-rich yet technically simple lab exercises, but it provides direct instruction to relatively inexperienced teachers via a "see and do" methodology. The proposal has two parts. First, a hands-on workshop for laboratory instructors at Cornell. Second, and very importantly, an instructional videotape for instructors showing step-by-step how to make each preparation is being produced. The intended target of these exercises include liberal arts college and university teachers, but our experience tells us that high-school teachers are perfectly capable of learning and employing these labs in their classes, and the workshop provides opportunities for them, as well. In summary, this proposal seeks to disseminate a thoroughly tested set of laboratory teaching exercises, proven to be stimulating to undergraduate students in many settings, to any teacher who wants to bring neuroscience content into his/her laboratory.

The goal of this project is to understand the bioacoustic and neurobehavioral basis of acoustic communication in insects, and the mechanisms underlying sound localization. Insects have proved to be good model systems for studying auditory neurobiology and behavior. We will investigate the tympanal hearing organs of an acoustic parasitoid fly, Ormia ochracea, because this insect appears to have "invented," in the evolutionary sense, a novel way to detect the direction of a sound source. Laser vibrometry is used to study the fly~s tympanal mechanics. The fly's eardrums are a new type of directional receiver: their mechanical response to sound permits them to overcome the extremely small ineraural difference cues that result from their minuscule size compared to much longer wavelength of the 5 kHz stimulus, that the fly must detect and localize. Even so, because of the fly~s small size, the magnitude of interaural disparity cues that are processed by the CNS for sound localization is still limited. Therefore this research will be directed at uncovering the auditory processing that underlies time coding in the fly~s nervous system. The findings from this investigation could have potential health relatedness if a miniature microphone based on the Ormiine fly's ears could be produced. Such a device might be small enough to confer directionality to hearing aids. The well-known and widely investigated acoustic startle response (ASR) of mammals as many parallels with the ultrasound ASR of flying crickets. Behavioral and psychoacoustic studies have been performed that show that the ASR of crickets can serve as a model system to investigate mechanisms of auditory processing that are ordinarily studied in vertebrates, including mammals. These include the precedence effect, habituation, dishabituation, sensitization, and categorical perception. In the cricket, however, the neural basis underlying auditory processing is subserved by much simpler neural systems, and it is here presented as a model system in which to investigate the neural processing that underlies complex acoustic behavior.

Some animals have highly exaggerated features such as plumage or antlers that are believed to have evolved from of sexual selection mechanisms. But some cases have further consequences for sensory processing, such as the extreme lateralization of eyes in hammerhead sharks, some crustaceans, and several insects. One extreme example is found in the diopsid family of flies known as 'stalk-eyed flies' where the eyes may be more than a body-length apart. It remains unknown whether there is unusual neuroanatomy, physiology or behavioral capabilities of the visual system in these animals. This project uses microscopy, electrophysiology and behavioral tests to compare the visual system of some stalk-eyed fly species to those of other insects and other arthropods, to see whether they have specific adaptations for binocular or even stereoscopic vision for distance estimation, and to see whether developing young flies require visual experience to use the eyes for distance perception.
Results will have a broad impact because they will be important not only for invertebrate vision, but in comparison with other animal visual systems, and for understanding the development and evolution of visual behavior. The project will provide excellent cross-disciplinary postdoctoral and undergraduate training.

Psychology - Cognitive (73) There has been an explosion of interest in matters relating cognition, brain, and behavior in the undergraduate curriculum. New courses in cognitive science are being introduced, while standard courses in neurobiology and psychology are being infused with material from cognitive science. Learning is most effective when students actively engage the subject. Thus psychology textbooks have traditionally used visual illusions to stimulate interest. Although compelling, such demonstrations are static and necessarily limited in scope. Ideally, students would not only experience illusions, but actively perform experiments, test modalities other than vision, and experience material from all areas of cognitive science. In general, it is not practical to provide full-fledged laboratories for large lecture courses such as introductory psychology, introductory neurobiology, or the emerging cognitive science courses. However, such courses often have discussion sections that would be enriched by experiments and interactive demonstrations. This project addresses these needs by development of a CD-ROM of experiments and demonstrations that can be used by students at their own computers or by instructors with projection equipment. Computers are now standard tools in the psychology research lab, and can be similarly used in teaching. Although many fine examples of illusions are scattered across the internet, they are heavily weighted toward vision, often lack explanation, and engage one only as a passive observer. This CD-ROM goes much further, using interactivity for experiments as well as demonstrations. Furthermore, it goes beyond vision to cover hearing, and beyond perception to allow students to replicate classic experiments in all areas of cognitive science. The CD-ROM covers several broad areas, including vision, hearing, language, learning and memory, attention, cognition, and practical applications. There are several modules devoted to each broad area. Each module generally includes (1) a demonstration of the phenomenon, taken from the real world where possible, (2) a demonstration with the salient features isolated, (3) a self-experiment to quantify the phenomenon, and (4) questions that stimulate students to form hypotheses and test them using the CD-ROM. Most modules are suitable for students at all levels, with introductory students simply viewing the demonstrations, and advanced students doing experiments and testing their own hypotheses. At all levels, the approach is open-ended and exploratory rather than strictly didactic. Faculty from Cornell's Department of Psychology and Cognitive Studies Program are active researchers in these fields and are available to assist us in choosing appropriate topics and recent experiments that are not yet covered in textbooks. Faculty from Cornell and elsewhere are also active in evaluating the CD-ROM during its development, both from their research expertise and by testing beta versions in their classrooms. Preliminary contacts with faculty from a variety of colleges and universities indicate considerable interest in this material. In addition, several publishers have shown interest in this project, making nationwide dissemination certain.

Lay Abstract
Hoy (0211770)
The functional organization and evolution of a novel insect visual system.

The eyes of insects, which are called compound eyes, are generally constructed from thousands of tiny lenses, each of which captures a single image point in space. Compound eyes are organized following a blueprint that is evolutionarily conserved throughout insects and even most crustaceans (shrimp, crabs etc.). Surprisingly, the twisted-wing insect (Strepsiptera), does not follow this blueprint but instead has an eye that represents an intermediate form between an image forming lens eye, such as found in vertebrates, and the typical insect eye. In this highly specialized, parasitic group of insects, several large lenses each capture a small image or "chunk" of the visual environment. These lens-based building blocks together form a small eye that samples a wide visual field. This project focuses on the functional organization of this unique eye. This intermediate organization escapes some of the classical limitations of both the compound eye and the single lens eye. A deeper understanding of the strepsipteran eye type could contribute to the growing field of biomimicry, where it could lead to new technologies for small sensors that sample wide visual fields.

Much of this project will be devoted to investigating the neural substrate that integrates the partial images supplied by individual lenses. In Strepsiptera the visual information from neighboring eyelets has to be integrated into one large coherent image. Understanding the design that performs such integration may reveal novel neural mechanisms in vision research. Because this eye is so different from that of all other insects, we will also investigate specific aspects of its development and use a comparative approach to investigate its evolutionary origin.

There are two major aspects in which this project will have a broader impact on our society: (1) it will reveal the organization, development and evolution of unique neural and optical structures which are interesting as adaptations to a specific life style, and may have the potential to become the basis for future technologies, and (2) it will provide considerable educational benefits, both in terms of training students and in terms of educating the greater public. Several undergraduate students will be involved at any given time throughout the project. These students will have the opportunity to become members of an active research laboratory where they will be exposed to many different techniques andcross-disciplinary training. Also, various forms of outreach and public education, ranging from a web-page in lay language to the design of a museum exhibit will be pursued. Interest of the public already has been expressed after initial publication on those eyes in Science, which lead to articles in National Geographic, Time Magazine, New York Times, Scientific American, Discovery, and others.

The Bio2010 report of the National Research Council identifies integration of mathematics into biology as an important part of modernizing the undergraduate curriculum. We propose to advance this goal in the behavioral sciences by producing a CD of interactive simulations and experiments in mathematical modeling. The behavioral sciences rely on mathematics not only for data analysis, but for models that explain behavior and its origins. However, undergraduate texts typically gloss over modeling, and there are few resources for those who would teach it. We are developing prototypes of modules covering a range of topics. They are intended to be used together in a course on behavior or singly in introductory biology, ecology, and evolution. Each starts with a video of a behavior and prompts students to consider the questions it raises. Next, students are led (both verbally and mathematically) through development of a model. Students then form hypotheses about the behavior and test their predictions with a graphical simulation of the model. While the mathematics behind these models does not go beyond algebra, the effect of varying parameters is often not obvious. Interactive simulations allow students to explore on their own as they develop understanding of modeling and a feel for the link between model parameters and behavior. The intellectual merits of this project are the improvement of the undergraduate biology curriculum by introducing mathematical modeling in a context that is accessible and interesting to students and the use of technology to advance teaching goals that cannot otherwise be met. This project is having an immediate impact in Cornell's large animal behavior course, where we are doing initial testing. Broader impact will come from publication of the material and use
nationwide in other colleges and universities. Faculty from departments of biology, psychology, anthropology, and mathematics at a variety of other institutions have indicated need for this material and willingness to test it in their classes as part of our evaluation plan. Several publishers, including that of the most widely used animal behavior text, have shown interest, making nationwide dissemination certain.

Biological Sciences (61). This project is developing instructional modules at the undergraduate level that focus on mathematical modeling in the behavioral sciences. These modules cover such topics as mating strategies, contests, habitat selection, foraging, cooperation and conflict, and communication. The focus is on well-understood models of animal behavior, with students encouraged to extend the models to human behavior, politics, and economics. Modules can be used together in behavior courses or singly in introductory biology, ecology, evolution, sociology, or psychology courses. A secondary aspect of the project is enhancement of mathematics classes by introducing behavioral applications. Each module actively engages the student in developing a model. After watching video of a behavior that illustrates a question, a student identifies the relevant variables, formulates a model, translates it to mathematical form, makes predictions based on the model, tests those predictions with a graphical simulation, and designs real-world experiments that would test the model. These exercises give students experience with probability, game theory, and optimization methods. A manual for instructors suggests ways to incorporate the material into a variety of courses and indicates areas that students may explore further on their own. This material is being tested at a diverse group of colleges and universities. Evaluation includes comparative tests (lecture-only vs. module) and longer-term tests of retention and transfer of knowledge. Dissemination of the material through national meetings, educational publications, and distribution by a textbook publisher is broadening the impact of the project and increasing the exposure of undergraduates nationwide to mathematical modeling of behavior.

DESCRIPTION (provided by applicant): The long-term goal of this laboratory is to understand how biomechanics, anatomy, and physiology enable hearing of high sensitivity and directional acuity. This proposal focuses on microscale ears because physical constraints make sound localization and high sensitivity extraordinarily challenging with ears of microscale dimension. Mosquitoes are among the smallest animals that hear. They possess antennae attached to Johnston's hearing organs (JOs) as external appendages on their heads. JOs are functionally analogous to the mammalian cochlea, but far more accessible. This work will use Doppler laser vibrometry to measure mechanical responses and physiological recordings to test the sensitivity of the two antennae. Preliminary data show that these ears are sensitive to sound over a large bandwidth and have modes of vibration substantially different from those published before. These data will lead to a mathematical model of antennal vibration. Preliminary calculations already indicate that antennae may have noise characteristics superior to those of tympana. The Aedes mosquito is not the smallest insect that hears. Interestingly, the antennae of even tinier midges and of even larger mosquito species are all about the same size. This suggests that they are all near the lower size limit for acoustic function. Comparing ears in these three species may reveal the limits of auditory function. The over 30,000 sensory cells of the JO have a unique and highly-ordered architecture that suggest tonotopic organization and modality fractionation enabling performance equal to macroscopic ears. Mosquito antennae respond to gravity and wind as well as to sound. The basic structure and function of antennae will be probed with molecular markers to determine functional subdivisions among its mechanosensory neurons. This research is relevant to public health and the mission of NIDCD. Far-field particle velocity and antennal ears are a relatively unexplored realm of auditory acoustics at small size. A goal of this work is to reveal the basic principles behind auditory function at all size scales. Miniaturization is coveted goal in practical engineering. The design features of these miniature ears could motivate mechanical engineers to biomimic and translate them into novel nano-to-microscale directional microphones. These findings potentially extend well beyond mere entomological curiosity.

All visual animals face the problem of distinguishing relevant from distracting stimuli quickly and efficiently. One way that visual systems accomplish this task is through selective attention, where an animal attends to a portion of the available visual stimuli at a time. Tiny jumping spiders have microminiature eyes that are nearly as acute as a human's and, like humans, pays attention and discriminates among visual targets. This project investigates how jumping spiders pay attention to and identify moving visual objects. The simplicity of the jumping spider eye and brain makes it easier to learn how the brain's neural networks "compute" visual movement and object identification, than in humans. In humans AND jumping spiders, selective visual attention is measured by rapid movements of their eyes to focus on targets of interest. This study employs an innovative eyetracker to measure the direction of a spider's gaze as it views video images. In addition, neural techniques are used to measure the activity of the spider's brain while its gaze is being monitored: specific parts of the brain respond differentially to particular images and sounds. Thus, it is possible to see both what engages a spider's visual attention as well as how different stimuli are interpreted. Understanding this elegant, miniaturized and extremely effective visual system will be of interest to roboticists and engineers, for whom micro-miniaturization of biosensors is a premium in small, self-autonomous robots. In addition, the PI will train a graduate student, a postdoc, and undergraduates, and will create videos for a project called "Faces and Voices of Science" that highlight the personal stories of researchers from different backgrounds. The videos will be made available online for teachers and professors to incorporate in lectures.


Visual animals face the problem of distinguishing relevant from distracting stimuli quickly and efficiently. One way to do this is through selective attention, where the animal attends to only part of the visual field at a time, through a process of saccadic eye movements and selective target scan. This is true for humans and at the behavioral level seems true for jumping spiders. These spiders are highly visual and are among the rare invertebrate animals that have moveable eyes. The PIs have developed two novel technologies that allow a comprehensive study of selective visual attention. These include an innovative spider eyetracker can monitor with precision a spider's eye movements in real time as they scan a stimulus image and the first electrophysiological recordings in the brain of a living spider as it observes visual stimuli. The eyetracker will be deployed to monitor eye movements while simultaneously recordings from single units in the brain are recorded. The PIs will thus test explicit hypotheses about visual attention, eye movements, and correlated brain activity. These include "bottom-up" stimulus-driven attentional processes by testing how different visual stimuli influence eye movements and neural processes in the brain, as well as "top-down" processes by presenting cross-modal cues and measuring eye movements and neural processes as the spider searches for relevant stimuli among distractors.

If there is one thing everyone “knows” about spiders, it’s that they are deadly hunters of insects, which they catch with webs spun of super-strong silk. Studying spiders can provide numerous engineering insights by examining the specialized sensory systems and ingenious uses of webs and silk they use for detecting and capturing prey. This project focuses on net-casting deinopid spiders that hunt by striking at moving insects that they ensnare in small rectangular webs held with their legs. This study will examine the large eyes of deinopid spiders, eyes that are used at night to hunt. The project is expected to produce results with practical applications. For example, the biochemical and physiological design features of their eyes are expected to reveal new insights that could be applied for night motion-sensitive devices. In addition, the remarkable physical properties of spider silk--namely, its tensile strength, toughness, and flexibility--are currently being exploited by industry for consumer, industrial, and military applications. This project will also have educational impacts by providing research opportunities for under-represented high school and undergraduate students and by developing an interactive bilingual game in English and Spanish to help teach children mathematics through modeling. These activities will broaden participation in science and help train the next generation of the scientific workforce.

This project will address complex questions requiring an integrative approach: How do sensory systems become specialized and what are the mechanisms behind these specializations? Net-casting spiders (Deinopidae) present an exciting model given their highly specialized sensory systems used to capture prey in near-total darkness. Net-casting spiders rely on enlarged eyes that are among the most light-sensitive on Earth. Yet some select species have diminutive eyes but forage under similar conditions. A recent discovery revealed that spiders use acoustic information transmitted through silk to perceive their environment and capture aerial prey. This suggests that trade-offs between sensory systems are a driver of adaptive variation. Functional trade-offs are inherent to all sensory systems, but the understanding of how these trade-offs manifest and evolve is limited and has not been studied in detail in a comparative fashion across multiple biological levels. Achieving this deep understanding of trade-offs requires integrative approaches and a diverse team of investigators willing to bridge the considerable gaps between their subdisciplines. This research will forge connections among investigators with complementary expertise in disparate biological fields. Together, they will identify the genetic, physiological, morphological, and behavioral mechanisms underlying the extraordinary visual and acoustic sensory adaptations within deinopids and elucidate how relative investments evolve in different ecological conditions. Results from the multidisciplinary empirical experiments will be integrated into an ecological and evolutionary model to generate predictions about sensory evolution that will be applicable to other biological systems. Cross-training of early career investigators will also strengthen the pipeline for integrative biology for generations.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.