For over a half-Century, the mathematics requirement for graduation at most undergraduate colleges and universities has been one year of calculus and a semester of statistics. Many universities and ...colleges offer a neuroscience major that may or may not add additional mathematics, statistics, or data science requirements. Today in the age of Big Data and Systems Neuroscience, many students are ill-equipped for the future without the tools of computational competency that are necessary to tackle the large data sets generated by contemporary neuroscience research. Required courses in statistics still focus on parametric statistics based on the normal distribution and do not provide the computational tools required to analyze big data sets. Undergraduates in STEM fields including neuroscience need to enroll in the Data Science courses that are required in the social sciences (e.g., economics, political science and psychology). Contemporary systems neuroscience is routinely done by interdisciplinary research teams of statisticians, engineers, and physical scientists. Emerging “NeuroX-omics” such as connectomics have emerged along with genomics, proteomics, and transcriptomics, all of which deploy systems analysis techniques based on mathematical graph theory. Connectomics is the 21st Century’s functional neuroanatomy. Whole brain connectome research appears almost monthly in the Drosphila, zebra fish, and mouse literature, and human brain connectomics is not far behind. The techniques for connectomics rely on the tools of data science. Undergraduate neuroscience students are already squeezed for credit hours given the high-prescribed science curriculum for biology majors and premedical students, in addition to required courses in social sciences and humanities. However, additional training in mathematics, statistics, computer science, and/or data science is urgently needed for undergraduate neuroscience majors just to understand the contemporary research literature. Undoubtedly, the faculty who teach neuroscience courses are acutely aware of the problem and most of them freely acknowledge the importance of quantitative analytical skills for their students. However, some faculty members may feel that their own math and statistics knowledge or other analytical skills have atrophied beyond recall or were never fulfilled in the first place. In this commentary I suggest that this problem can be ameliorated, though not solved, through organizing workshops, journal clubs, or independent studies courses in which the students and the instructors learn and teach each other in short-course format. In addition, web-available teaching materials such as targeted video clips are plentifully available on the internet. To attract and maintain student interest, qauntitative instruction and learning should occur in neuroscience context.
Mating behavior in Aedes aegypti mosquitoes occurs mid-air and involves the exchange of auditory signals at close range (millimeters to centimeters) 1–6. It is widely assumed that this intimate ...signaling distance reflects short-range auditory sensitivity of their antennal hearing organs to faint flight tones 7, 8. To the contrary, we show here that male mosquitoes can hear the female’s flight tone at surprisingly long distances—from several meters to up to 10 m—and that unrestrained, resting Ae. aegypti males leap off their perches and take flight when they hear female flight tones. Moreover, auditory sensitivity tests of Ae. aegypti’s hearing organ, made from neurophysiological recordings of the auditory nerve in response to pure-tone stimuli played from a loudspeaker, support the behavioral experiments. This demonstration of long-range hearing in mosquitoes overturns the common assumption that the thread-like antennal hearing organs of tiny insects are strictly close-range ears. The effective range of a hearing organ depends ultimately on its sensitivity 9–13. Here, a mosquito’s antennal ear is shown to be sensitive to sound levels down to 31 dB sound pressure level (SPL), translating to air particle velocity at nanometer dimensions. We note that the peak of energy of the first formant of the vowels of the human speech spectrum range from about 200–1,000 Hz and is typically spoken at 45–70 dB SPL; together, they lie in the sweet spot of mosquito hearing.
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•The mosquito Aedes aegypti hears sound over surprisingly long distances•Behavioral and physiological experiments confirm a range of audibility up to 10 m•Ae. aegypti is sensitive to sound frequencies of 150–500 Hz•The vowel sounds of human speech contain energy at 150–500 Hz
Previous behavioral work shows that mosquitos hear sounds just a few centimeters away. Menda et al.’s behavioral and physiological experiments show that Aedes aegypti mosquitos can hear up to 10 m away. Notably, the vowel sounds of human speech contain frequencies that are spoken at levels which, in principle, are audible to mosquitos.
Jumping spiders (Salticidae) are famous for their visually driven behaviors 1. Here, however, we present behavioral and neurophysiological evidence that these animals also perceive and respond to ...airborne acoustic stimuli, even when the distance between the animal and the sound source is relatively large (∼3 m) and with stimulus amplitudes at the position of the spider of ∼65 dB sound pressure level (SPL). Behavioral experiments with the jumping spider Phidippus audax reveal that these animals respond to low-frequency sounds (80 Hz; 65 dB SPL) by freezing—a common anti-predatory behavior characteristic of an acoustic startle response. Neurophysiological recordings from auditory-sensitive neural units in the brains of these jumping spiders showed responses to low-frequency tones (80 Hz at ∼65 dB SPL)—recordings that also represent the first record of acoustically responsive neural units in the jumping spider brain. Responses persisted even when the distances between spider and stimulus source exceeded 3 m and under anechoic conditions. Thus, these spiders appear able to detect airborne sound at distances in the acoustic far-field region, beyond the near-field range often thought to bound acoustic perception in arthropods that lack tympanic ears (e.g., spiders) 2. Furthermore, direct mechanical stimulation of hairs on the patella of the foreleg was sufficient to generate responses in neural units that also responded to airborne acoustic stimuli—evidence that these hairs likely play a role in the detection of acoustic cues. We suggest that these auditory responses enable the detection of predators and facilitate an acoustic startle response.
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•We present evidence that jumping spiders, famously visual, perceive airborne sounds•Spiders responded to low 80 Hz tones by freezing—an acoustic startle response•Neural recordings revealed units in the brain that respond to airborne acoustic cues•Neural responses to 80–380 Hz (∼65 dB SPL) persisted at far-field distances (>3 m)
Jumping spiders are renowned visual specialists. Here, Shamble et al. provide evidence that they also respond to airborne acoustic cues. Behaviorally, stimuli caused spiders to freeze, while neural responses to stimuli of ∼65 dB SPL persisted even at ranges of 3 m, well beyond what has been previously reported in similar systems.
The familiar buzz of flying mosquitoes is an important mating signal, with the fundamental frequency of the female's flight tone signaling her presence. In the yellow fever and dengue vector Aedes ...aegypti, both sexes interact acoustically by shifting their flight tones to match, resulting in a courtship duet. Matching is made not at the fundamental frequency of 400 hertz (female) or 600 hertz (male) but at a shared harmonic of 1200 hertz, which exceeds the previously known upper limit of hearing in mosquitoes. Physiological recordings from Johnston's organ (the mosquito's "ear") reveal sensitivity up to 2000 hertz, consistent with our observed courtship behavior. These findings revise widely accepted limits of acoustic behavior in mosquitoes.
SignificanceThe sense of hearing in all known animals relies on possessing auditory organs that are made up of cellular tissues and constrained by body sizes. We show that hearing in the orb-weaving ...spider is functionally outsourced to its extended phenotype, the proteinaceous self-manufactured web, and hence processes behavioral controllability. This finding opens new perspectives on animal extended cognition and hearing-the outsourcing and supersizing of auditory function in spiders. This study calls for reinvestigation of the remarkable evolutionary ecology and sensory ecology in spiders-one of the oldest land animals. The sensory modality of outsourced hearing provides a unique model for studying extended and regenerative sensing and presents new design features for inspiring novel acoustic flow detectors.
Jumping spiders (Salticidae) are renowned for a behavioral repertoire that can seem more vertebrate, or even mammalian, than spider-like in character 1–3. This is made possible by a unique visual ...system that supports their stalking hunting style and elaborate mating rituals in which the bizarrely marked and colored appendages of males highlight their song-and-dance displays 2, 4, 5. Salticids perform these tasks with information from four pairs of functionally specialized eyes, providing a near 360° field of view and forward-looking spatial resolution surpassing that of all insects and even some mammals 1, processed by a brain roughly the size of a poppy seed. Salticid behavior, evolution, and ecology are well documented 6–8, but attempts to study the neurophysiological basis of their behavior had been thwarted by the pressurized nature of their internal body fluids, making typical physiological techniques infeasible and restricting all previous neural work in salticids to a few recordings from the eyes 9, 10. We report the first survey of neurophysiological recordings from the brain of a jumping spider, Phidippus audax (Salticidae). The data include single-unit recordings in response to artificial and naturalistic visual stimuli. The salticid visual system is unique in that high-acuity and motion vision are processed by different pairs of eyes 1. We found nonlinear interactions between the principal and secondary eyes, which can be inferred from the emergence of spatiotemporal receptive fields. Ecologically relevant images, including prey-like objects such as flies, elicited bursts of excitation from single units.
•We report the first neural recordings from visual brain areas in jumping spiders•We recorded single-unit responses to ethologically salient stimulus images•We present evidence for nonlinear interactions between different sets of eyes
Jumping spiders are renowned for visually driven predation and semaphore-like mating displays. Menda et al. report the first single-unit neurophysiological recordings of visual interneurons in the salticid brain, thus opening up their charismatic behavioral acts to neuroethological analysis.
Jumping spiders have extraordinary vision. Using multiple, specialized eyes, these spiders selectively gather and integrate disparate streams of information about motion, color, and spatial detail. ...The saccadic movements of a forward-facing pair of eyes allow spiders to inspect their surroundings and identify objects. Here, we discuss the jumping spider visual system and how visual information is attended to and processed.
Prey capture behavior among spiders varies greatly from passive entrapment in webs to running down prey items on foot. Somewhere in the middle are the ogre-faced, net-casting spiders 1 (Deinopidae: ...Deinopis) that actively capture prey while being suspended within a frame web 2–5. Using a net held between their front four legs, these spiders lunge downward to ensnare prey from off the ground beneath them. This “forward strike” is sensorially mediated by a massive pair of hypersensitive, night-vision eyes 5–7. Deinopids can also intercept flying insects with a “backward strike,” a ballistically rapid, overhead back-twist, that seems not to rely on visual cues 4, 5, 8. Past reports have hypothesized a role of acoustic detection in backward strike behavior 4, 5, 8. Here, we report that the net-casting spider, Deinopis spinosa, can detect auditory stimuli from at least 2 m from the sound source, at or above 60 dB SPL, and that this acoustic sensitivity is sufficient to trigger backward strike behavior. We present neurophysiological recordings in response to acoustic stimulation, both from sound-sensitive areas in the brain and isolated forelegs, which demonstrate a broad range of auditory sensitivity (100–10,000 Hz). Moreover, we conducted behavioral assays of acoustic stimulation that confirm acoustic triggering of backward net-casting by frequencies in harmony with flight tones of known prey. However, acoustic stimulation using higher frequency sounds did not elicit predatory responses in D. spinosa. We hypothesize higher frequencies are emitted by avian predators and that detecting these auditory cues may aid in anti-predator behavior.
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•D. spinosa are acoustically sensitive to a wide range of airborne tonal frequencies•Spiders respond to low-frequency tones as if capturing a flying insect•Spiders do not behaviorally respond to high-frequency tones in a foraging context•The metatarsal organ seems to play a role in acoustic detection
Stafstrom et al. show that ogre-faced spiders are acoustically sensitive to a wide range of airborne tonal frequencies (100–10,000 Hz). By combining neurophysiological and behavioral experiments, spiders are shown to use low-frequency detection to capture flying prey. The behavioral relevance of high-frequency acoustic detection remains unknown.
Most mosquito and midge species use hearing during acoustic mating behaviors. For frog-biting species, however, hearing plays an important role beyond mating as females rely on anuran calls to obtain ...blood meals. Despite the extensive work examining hearing in mosquito species that use sound in mating contexts, our understanding of how mosquitoes hear frog calls is limited. Here, we directly investigated the mechanisms underlying detection of frog calls by a mosquito species specialized on eavesdropping on anuran mating signals: Uranotaenia lowii. Behavioral, biomechanical and neurophysiological analyses revealed that the antenna of this frog-biting species can detect frog calls by relying on neural and mechanical responses comparable to those of non-frog-biting species. Our findings show that in Ur. lowii, contrary to most species, males do not use sound for mating, but females use hearing to locate their anuran host. We also show that the response of the antennae of this frog-biting species resembles that of the antenna of species that use hearing for mating. Finally, we discuss our data considering how mosquitoes may have evolved the ability to tap into the communication system of frogs.
Ronald R. Hoy Hoy, Ronald R.
Current biology,
11/2014, Letnik:
24, Številka:
21
Journal Article
Recenzirano
Odprti dostop
A Q&A with Ron Hoy, whose career has focused on the neuroethology and bioacoustics of insect songs, and whose laboratory is presently working on multimodal integration, particularly of acoustic and ...visual signals.
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