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Allen F. Mensinger - One of the best experts on this subject based on the ideXlab platform.
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The effect of biological and anthropogenic sound on the auditory sensitivity of oyster toadfish, Opsanus Tau
Journal of Comparative Physiology A, 2019Co-Authors: Loranzie S. Rogers, Rosalyn L. Putland, Allen F. MensingerAbstract:Many aquatic organisms use vocalizations for reproductive behavior; therefore, disruption of their soundscape could adversely affect their life history. Male oyster toadfish ( Opsanus Tau ) establish nests in shallow waters during spring and attract female fish with boatwhistle vocalizations. Males exhibit high nest fidelity, making them susceptible to anthropogenic sound in coastal waters, which could mask their vocalizations and/or reduce auditory sensitivity levels. Additionally, the effect of self-generated boatwhistles on toadfish auditory sensitivity has yet to be addressed. To investigate the effect of sound exposure on toadfish auditory sensitivity, sound pressure and particle acceleration sensitivity curves were determined using auditory evoked potentials before and after (0-, 1-, 3-, 6- and 9-day) exposure to 1- or 12-h of continuous playbacks to ship engine sound or conspecific vocalization. Exposure to boatwhistles had no effect on auditory sensitivity. However, exposure to anthropogenic sound caused significant decreases in auditory sensitivity for at least 3 days, with shifts up to 8 dB SPL and 20 dB SPL immediately following 1- and 12-h anthropogenic exposure, respectively. Understanding the effect of self-generated and anthropogenic sound exposure on auditory sensitivity provides an insight into how soundscapes affect acoustic communication.
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long term pam to investigate temporal and anthropogenic effects on oyster toadfish Opsanus Tau mating vocalizations
Journal of the Acoustical Society of America, 2019Co-Authors: Rosalyn L. Putland, Allen F. Mensinger, Jacey C Van Wert, Alayna MackiewiczAbstract:For the oyster toadfish, Opsanus Tau, vocal communication and sound detection are critical for reproductive success, however, little is known about how they respond to changes in their acoustic environment. Passive acoustic monitoring was conducted in Eel Pond, MA, USA in the summer months (2017–2019) to investigate vocalization patterns of the resident population and the effect of anthropogenic sound. Male toadfish produce mating vocalizations that are characterized by an initial broadband segment (30–50 ms, 100–1000 Hz) and a longer tonal section (200–650 ms, 100–500 Hz). The pulse repetition rate of the tonal section was significantly related to ambient water temperature during hourly and weekly monitoring. Time difference of arrivals were also used to pinpoint the location of toadfish nests and linked to ambient and anthropogenic sound-maps to understand exposure levels for individual fish. Significantly less vocalizations were detected following exposure to vessel sound (100–12 000 Hz, source level 130 dB re 1 μPa), suggesting individuals changed their vocal behavior in response to anthropogenic activity. Both environmental and the presence of vessel sound influence the acoustic behaviour of toadfish, which could lead to a reduction in communication space, mate attraction and detection.For the oyster toadfish, Opsanus Tau, vocal communication and sound detection are critical for reproductive success, however, little is known about how they respond to changes in their acoustic environment. Passive acoustic monitoring was conducted in Eel Pond, MA, USA in the summer months (2017–2019) to investigate vocalization patterns of the resident population and the effect of anthropogenic sound. Male toadfish produce mating vocalizations that are characterized by an initial broadband segment (30–50 ms, 100–1000 Hz) and a longer tonal section (200–650 ms, 100–500 Hz). The pulse repetition rate of the tonal section was significantly related to ambient water temperature during hourly and weekly monitoring. Time difference of arrivals were also used to pinpoint the location of toadfish nests and linked to ambient and anthropogenic sound-maps to understand exposure levels for individual fish. Significantly less vocalizations were detected following exposure to vessel sound (100–12 000 Hz, source level 1...
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seasonal and daily patterns of the mating calls of the oyster toadfish Opsanus Tau
The Biological Bulletin, 2019Co-Authors: Jacey C Van Wert, Allen F. MensingerAbstract:AbstractAcoustic communication is vital across many taxa for mating behavior, defense, and social interactions. Male oyster toadfish, Opsanus Tau, produce courtship calls, or “boatwhistles,” charac...
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lateral line sensitivity in free swimming toadfish Opsanus Tau
The Journal of Experimental Biology, 2019Co-Authors: Loranzie S. Rogers, Allen F. Mensinger, Jacey C Van WertAbstract:A longstanding question in aquatic animal sensory physiology is the impact of self-generated movement on lateral line sensitivity. One hypothesis is that efferent modulation of the sensory hair cells cancels self-generated noise and allows fish to sample their surroundings while swimming. In this study, microwire electrodes were chronically implanted into the anterior lateral line nerve of oyster toadfish and neural activity was monitored during forward movement. Fish were allowed to freely swim or were moved by a tethered sled. In all cases, neural activity increased during movement with no evidence of efferent modulation. The anterior lateral line of moving fish responded to a vibrating sphere or the tail oscillations of a robotic fish, indicating that the lateral line also remains sensitive to outside stimulus during self-generated movement. The results suggest that during normal swim speeds, lateral line neuromasts are not saturated and retain the ability to detect external stimuli without efferent modulation.
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potential role of the anterior lateral line in sound localization in toadfish Opsanus Tau
The Journal of Experimental Biology, 2018Co-Authors: Allen F. Mensinger, Emily A Cardinal, Craig A RadfordAbstract:Male oyster toadfish (Opsanus Tau) acoustically attract females to nesting sites using a boatwhistle call. The rapid speed of sound underwater combined with the close proximity of the otolithic organs makes inner ear interaural time differences an unlikely mechanism to localize sound. To determine the role that the mechanosensory lateral line may play in sound localization, microwire electrodes were bilaterally implanted into the anterior lateral line nerve to record neural responses to vibrational stimuli. Highest spike rates and strongest phase-locking occurred at distances close to the fish and decreased as the stimulus was moved further from the fish. Bilateral anterior lateral line neuromasts displayed differential directional sensitivity to incoming vibrational stimuli, which suggests the potential for the lateral line to be used for sound localization in the near field. The present study also demonstrates that the spatially separated neuromasts of the toadfish may provide sufficient time delays between sensory organs for determining sound localization cues. Multimodal sensory input processing through both the inner ear (far field) and lateral line (near field) may allow for effective sound localization in fish.
Stephen M. Highstein - One of the best experts on this subject based on the ideXlab platform.
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Chronic Recording of Regenerating VIIIth Nerve Axons With a Sieve Electrode
2015Co-Authors: Stephen M. Highstein, Robert B. Silver, Patrick A Tresco, David C. Martin, Allen F, David J. Anderson, Christopher J. Buchko, Michael A. JohnsonAbstract:erating VIIIth nerve axons with a sieve electrode. J. Neurophysiol. 83: 611–615, 2000. A micromachined silicon substrate sieve electrode was implanted within transected toadfish (Opsanus Tau) otolith nerves. High fidelity, single unit neural activity was recorded from seven alert and unrestrained fish 30 to 60 days after implantation. Fibrous coat-ings of genetically engineered bioactive protein polymers and nerve guide tubes increased the number of axons regenerating through the electrode pores when compared with controls. Sieve electrodes have potential as permanent interfaces to the nervous system and to bridge missing connections between severed or damaged nerves and muscles. Recorded impulses might also be amplified and used to control prosthetic devices
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Dendritic arbors and central projections of physiologically characterized auditory fibers from the saccule of the toadfish, Opsanus Tau
The Journal of Comparative Neurology, 1999Co-Authors: Peggy L Edds-walton, Richard R. Fay, Stephen M. HighsteinAbstract:Neurobiotin was injected iontophoretically into saccular afferents of toadfish (Opsanus Tau) after intracellular recording to examine dendritic arbors and central projections with respect to the physiological and directional response properties of the cells. Dendritic arbors of 36 afferents were examined in detail. Maximum diameter of the arbor and the number of terminal points were positively correlated with each other, but neither was predictive of spontaneous activity or sensitivity. Best azimuths were centered around 30 degrees -40 degrees, which corresponds to the angle of the saccule with respect to the fish's midline. In general, best elevations for afferents corresponded to hair cell orientations in the region innervated; unexpectedly low elevations obtained from afferents innervating the middle saccule may reflect curvature of the sensory epithelium against the otolith. Three efferent cells were filled partially. The location and large size of the efferent projections indicate that activity along the saccule could be modulated by a single efferent. All afferents projected to the dorsal zone of the descending octaval nucleus (dDON); many afferents bifurcated to terminate in the anterior octaval nucleus, and a few of those also had terminal fields in the medial zone of DON. All afferent projections into the dDON consisted of multiple axon collaterals projecting to numerous sites along the rostral-caudal extent of the nucleus. Variation in terminal field sites also was noted in the medial to lateral axis of the dDON; however, there were no consistent correlations between terminal field locations, physiology, and best directions of the saccular afferents.
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Characteristics of regenerating horizontal semicircular canal afferent and efferent fibers in the toadfish, Opsanus Tau.
The Journal of comparative neurology, 1999Co-Authors: Allen F. Mensinger, Stephen M. HighsteinAbstract:The horizontal semicircular canal nerve of the toadfish, Opsanus Tau, was transected and allowed to regenerate. The time course, morphometrics, and projection patterns of regenerating afferent and efferent vestibular fibers were determined. Nerve transections were performed both pre- and postganglionically, and regeneration was assessed in afferent and efferent fibers by bulk labeling the peripheral axons of the horizontal semicircular canal nerve with biocytin after nerve regrowth. Afferent fibers regrew through the transection site within 14 days and projected to all vestibular nuclei within 3 weeks. Bouton and branch number, axon length, surface area, volume, fiber diameter, and internodal distance were quantified for afferent fibers from eight sites within the vestibular nuclei, and axon number and soma size was quantified for the efferent fibers. Extensive regeneration was seen within 5 weeks of transection in all nuclei, and most morphometric parameters approached or exceeded control levels within 10 weeks. Regeneration appeared to recapitulate morphogenesis with an initial overproduction of boutons and branch points followed by elimination of presumably superfluous structures. Internodal distance remained significantly shorter in regenerating afferent axons than in control fish throughout the 15-week observation period. Efferent fibers also were observed to regenerate. Efferent axon number, diameter, and soma size were indistinguishable from those in controls from 3 weeks posttransection through week 15. Electrophysiological recordings from the horizontal canal nerve during mechanical stimuli of the canal confirmed that the regenerated axons transmitted normal signals. The return of normal equilibrium and behavior coincided with the projection of afferent fibers into the central vestibular nuclei, indicating that functional connections had been reestablished.
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Examination of the cupula and stereocilia of the horizontal semicircular canal in the toadfish Opsanus Tau
The Journal of comparative neurology, 1998Co-Authors: Robert B. Silver, Anthony P. Reeves, Antionette Steinacker, Stephen M. HighsteinAbstract:We imaged the horizontal semicircular canal (HSCC) crista and cupula of toadfish, Opsanus Tau, by using a) confocal light microscopy of isolated vital HSCC; b) serial sections of fixed, trichrome-stained HSCC; and c) scanning electron microscopy of fixed HSCCs. HSCC were dissections which included an ampulla and an attached canal tube (long and slender canal portion), and, in some cases, a small portion of the utricular wall. Cupulae were seen as multipartite mucus connective tissue shells rising from the crista and extending toward the ampullary roof. They were composed of several refractile bands traversing the cupulae perpendicular to longitudinal fibers extending from the cupular base to its apex. Alcian green–stained cupulae showed an asymmetric alcianphilic, dark, X-shaped structure, indicating that the pillar is rich in mucin and carbohydrate, an interpretation supported by images of trichrome-stained sections. The cupular antrum is devoid of prominent refractile fibers. No tubes or channels were observed in the cupula or antrum of vital preparations. Cupular shell fibers cover the surface of the crista, are roughly parallel, and are associated with a translucent material having a refractive index greater than the surrounding endolymph. Stereocilia were thin, 100-μm-long structures, with little longitudinal curvature, which end with no end bulb. No strands extend from stereocilia to the roof or other portions of the cupular antrum. Gross movements of stereocilia were not seen in mechanically quiescent preparations. Within the cupular antrum, stereocilia were parallel to connective tissue fibers, all embedded in an isotropic gel. This fiber-reinforced gel and cupular matrix are sensitive to N-acetlyneuraminidase and β-N-acetyl glucosaminidase, and minimally sensitive to β-N-acetyl hexosaminidase. Connective tissue fibers may serve to stiffen the gel, whose matrix would restrict lateral motion of embedded fibers and stereocilia thereby providing mechanical support for stereocilia. J. Comp. Neurol. 402:48–61, 1998. © 1998 Wiley-Liss, Inc.
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differential central projections of physiologically characterized horizontal semicircular canal vestibular nerve afferents in the toadfish Opsanus Tau
The Journal of Comparative Neurology, 1997Co-Authors: Allen F. Mensinger, R Boyle, John P Carey, Stephen M. HighsteinAbstract:Anatomical and neurophysiological studies were undertaken to examine the central projection pattern of physiologically characterized horizontal semicircular canal vestibular nerve afferents in the toadfish,Opsanus Tau. The variations in individual response characteristics of vestibular nerve afferents to rotational stimulus provided a means of typing the afferents into descriptive classes; the afferents fell into a broad continuum across the spectrum from low-gain, velocity-sensitive to high-gain, acceleration-sensitive responses (Boyle and Highstein [1990b] J. Neurosci. 10:1557‐1569; Boyle and Highstein [1990a] J. Neurosci. 10:1570‐1582). In the present study, each afferent was typed as a low-gain, high-gain, or acceleration fiber during rotational or mechanical stimulation (Rabbitt et al. [1995] J. Neurophysiol. 73:2237‐2260) and was then intracellularly injected with biocytin. The axons were reconstructed, and the morphology, synaptic boutons, and projection pattern of each axon were determined. The results indicated that the three descriptive classes of vestibular nerve afferents have unique as well as overlapping central projection patterns and destinations in the vestibular nuclei, with intranuclear parcellation in the anterior octavus, magnocellularis, tangentialis, posterior octavus, and descending octavus nuclei. In general, increased sensitivity and faster response dynamics were correlated with both a more extensive central projection and a progressive increase in morphological complexity. Lowgain, velocity-sensitive fibers were the simplest morphologically, with the fewest number of branches (n 517) and shortest length (4,282 µm), and projections were confined to the middle portions of the vestibular nuclei. High-gain, velocity-sensitive fibers were morphologically more diverse than low-gain fibers, with a greater number of branches (n 5 26), longer length (6,059 µm), 29% greater volume, and a more widespread projection pattern with projections to both the anterior and the middle portions of the vestibular nuclei. Acceleration fibers were morphologically distinct from low- and high-gain fibers, with more elaborate branching (n 5 41), greatest overall length (17,370 µm) and volume (16% greater than high gains), and displayed the most extensive central projection pattern, innervating all vestibular nuclei except tangentialis. Thus, there are anatomically demonstrable differential central projections of canal afferents with different response dynamics within the vestibular complex of the fish. J. Comp. Neurol. 384:71‐85, 1997. r 1997 Wiley-Liss, Inc. Indexing terms: teleost; synaptic bouton; vestibular nuclei
Richard R. Fay - One of the best experts on this subject based on the ideXlab platform.
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Computerized tomography of the otic capsule and otoliths in the oyster toadfish, Opsanus Tau
Journal of morphology, 2014Co-Authors: Peggy L Edds-walton, Richard R. Fay, Julie Arruda, Darlene R. KettenAbstract:The neurocranium of the toadfish (Opsanus Tau) exhibits a distinct translucent region in the otic capsule (OC) that may have functional significance for the auditory pathway. This study used ultrahigh resolution computerized tomography (100 µm voxels) to compare the relative density of three sites along the OC (dorsolateral, midlateral, and ventromedial) and two reference sites (dorsal: supraoccipital crest; ventral: parasphenoid bone) in the neurocranium. Higher attenuation occurs where structural density is greater; thus, we compared the X-ray attenuations measured, which provided a measure of relative density. The maximum attenuation value was recorded for each of the five sites (x and y) on consecutive sections throughout the OC and for each of the three calcareous otoliths associated with the sensory maculae (lagena, saccule, and utricle) in the OC. All three otoliths had higher attenuations than any sites in the neurocranium. Both dorsal and ventral reference sites (supraoccipital crest and parasphenoid bone, respectively) had attenuation levels consistent with calcified bone and had relatively small, irregular variations along the length of the OC in all individuals. The lowest relative attenuations (lowest densities) occurred consistently at the three sites along the OC. In addition, the lowest attenuations measured along the OC occurred at the ventromedial site around the saccular otolith for all seven fish. The decrease in bone density along the OC is consistent with the hypothesis that there is a low-density channel in the skull to facilitate transmission of acoustic stimuli to the auditory endorgans of the ear.
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Does the magnocellular octaval nucleus process auditory information in the toadfish, Opsanus Tau?
Journal of Comparative Physiology A, 2013Co-Authors: Peggy L Edds-walton, Solymar Rivera Matos, Richard R. FayAbstract:Previous work on auditory processing in Opsanus Tau has focused on the descending octaval nucleus; however, the magnocellular octaval nucleus receives similar inputs from the otolithic endorgans. The purpose of this study was to assess whether cells in any of the three subdivisions of the magnocellular nucleus respond to auditory frequencies and encode sound source direction. Extracellular recording sites were chosen based on anatomical landmarks, and neurobiotin injections confirmed the location of auditory sites in subdivisions of the magnocellular nucleus. In general, the auditory cells in M2 and M3 responded best to frequencies at or below 100 Hz. Most auditory cells responded well to directional stimuli presented along axes in the horizontal plane. Cells in M3 (not M2) also responded to lateral line stimulation, consistent with otolithic endorgan and lateral line inputs to M3. The convergence of auditory and lateral line inputs in M3, the lack of Mauthner cells in this species, and previous evidence that the magnocellular nucleus does not contribute to ascending auditory pathways suggest to us that the large cells of M3 may play a role in rapid behavioral responses to particle motion stimuli in oyster toadfish.
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gamma aminobutyric acid is a neurotransmitter in the auditory pathway of oyster toadfish Opsanus Tau
Hearing Research, 2010Co-Authors: Richard R. Fay, Peggy L EddswaltonAbstract:Binaural computations involving the convergence of excitatory and inhibitory inputs have been proposed to explain directional sharpening and frequency tuning documented in the brainstem of a teleost fish, the oyster toadfish (Opsanus Tau). To assess the presence of inhibitory neurons in the ascending auditory circuit, we used a monoclonal antibody to GABA to evaluate immunoreactivity at three levels of the circuit: the first order descending octaval nucleus (DON), the secondary octaval population (dorsal division), and the midbrain torus semicircularis. We observed a subset of immunoreactive (IR) cells and puncta distributed throughout the neuropil at all three locations. To assess whether contralateral inhibition is present, fluorescent dextran crystals were inserted into dorsal DON to fill contralateral, commissural inputs retrogradely prior to GABA immunohistochemistry. GABA-IR somata and puncta co-occurred with retrogradely filled, GABA-negative auditory projection cells. GABA-IR projection cells were more common in the dorsolateral DON than in the dorsomedial DON, but GABA-IR puncta were common in both dorsolateral and dorsomedial divisions. Our findings demonstrate that GABA is present in the ascending auditory circuit in the brainstem of the toadfish, indicating that GABA-mediated inhibition participates in shaping auditory response characteristics in a teleost fish as in other vertebrates.
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directional and frequency response characteristics in the descending octaval nucleus of the toadfish Opsanus Tau
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 2008Co-Authors: Peggy L Eddswalton, Richard R. FayAbstract:This study is a continuation of a long-term investigation of the auditory circuit in the oyster toadfish, Opsanus Tau. Input from the auditory periphery projects to the ipsilateral descending octaval nucleus (DON). Ipsilateral and contralateral DONs project to the auditory midbrain, where a previous study indicated that both frequency tuning and directional sharpening are present. To better understand the transformation of auditory information along the auditory pathway, we have examined over 400 units in the DON to characterize frequency and directional information encoded in the dorsolateral division of the nucleus. Background activity was primarily low (<10 spikes/s) or absent. The maximum coefficient of synchronization was equivalent to the periphery (R = 0.9) and substantially better than in the midbrain. The majority of DON units (79%) responded best to stimulus frequencies of 84–141 Hz and were broadly tuned. DON cells retain or enhance the directional character of their peripheral input (s); however, characteristic axes were distributed in all quadrants around the fish, providing further evidence that binaural computations may first occur in the DON of this species.
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binaural interaction in the medulla and midbrain of toadfish Opsanus Tau
Journal of the Acoustical Society of America, 2007Co-Authors: Richard R. Fay, Peggy WaltonAbstract:Responses of cells in the toadfish medulla (descending octaval nucleus: DON) and midbrain (torus semicircularis: TS) were studied to investigate binaural interaction and processing. Normally, the two ears of fish cannot be stimulated independently. A method was developed to temporarily inactivate one ear by slightly displacing the saccular otolith on one side (tipping) to change its orientation in space and, therefore, alter the responsiveness of the hair cells. Brain cells were evaluated for directional characteristics and frequency response (1) before otolith tipping, (2) with the otolith tipped, and (3) post‐tipping. For DON cells (n=14), contralateral saccular otolith tipping most often resulted in subtle effects consisting of an overall change in responsiveness (±spikes/sec); significant changes in the preferred direction were rare. In the TS (n=20), most cells exhibited changes in responsiveness and in directionality. These experiments demonstrate the existence of excitatory and inhibitory binaural ...
Peggy L Eddswalton - One of the best experts on this subject based on the ideXlab platform.
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gamma aminobutyric acid is a neurotransmitter in the auditory pathway of oyster toadfish Opsanus Tau
Hearing Research, 2010Co-Authors: Richard R. Fay, Peggy L EddswaltonAbstract:Binaural computations involving the convergence of excitatory and inhibitory inputs have been proposed to explain directional sharpening and frequency tuning documented in the brainstem of a teleost fish, the oyster toadfish (Opsanus Tau). To assess the presence of inhibitory neurons in the ascending auditory circuit, we used a monoclonal antibody to GABA to evaluate immunoreactivity at three levels of the circuit: the first order descending octaval nucleus (DON), the secondary octaval population (dorsal division), and the midbrain torus semicircularis. We observed a subset of immunoreactive (IR) cells and puncta distributed throughout the neuropil at all three locations. To assess whether contralateral inhibition is present, fluorescent dextran crystals were inserted into dorsal DON to fill contralateral, commissural inputs retrogradely prior to GABA immunohistochemistry. GABA-IR somata and puncta co-occurred with retrogradely filled, GABA-negative auditory projection cells. GABA-IR projection cells were more common in the dorsolateral DON than in the dorsomedial DON, but GABA-IR puncta were common in both dorsolateral and dorsomedial divisions. Our findings demonstrate that GABA is present in the ascending auditory circuit in the brainstem of the toadfish, indicating that GABA-mediated inhibition participates in shaping auditory response characteristics in a teleost fish as in other vertebrates.
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directional and frequency response characteristics in the descending octaval nucleus of the toadfish Opsanus Tau
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 2008Co-Authors: Peggy L Eddswalton, Richard R. FayAbstract:This study is a continuation of a long-term investigation of the auditory circuit in the oyster toadfish, Opsanus Tau. Input from the auditory periphery projects to the ipsilateral descending octaval nucleus (DON). Ipsilateral and contralateral DONs project to the auditory midbrain, where a previous study indicated that both frequency tuning and directional sharpening are present. To better understand the transformation of auditory information along the auditory pathway, we have examined over 400 units in the DON to characterize frequency and directional information encoded in the dorsolateral division of the nucleus. Background activity was primarily low (<10 spikes/s) or absent. The maximum coefficient of synchronization was equivalent to the periphery (R = 0.9) and substantially better than in the midbrain. The majority of DON units (79%) responded best to stimulus frequencies of 84–141 Hz and were broadly tuned. DON cells retain or enhance the directional character of their peripheral input (s); however, characteristic axes were distributed in all quadrants around the fish, providing further evidence that binaural computations may first occur in the DON of this species.
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diversity in frequency response properties of saccular afferents of the toadfish Opsanus Tau
Hearing Research, 1997Co-Authors: Richard R. Fay, Peggy L EddswaltonAbstract:The frequency response of primary saccular afferents of toadfish (Opsanus Tau) was studied in the time and frequency domains using the reverse correlation (revcor) method. Stimuli were noise bands with flat acceleration spectra delivered as whole-body motion. The recorded acceleration waveform was averaged over epochs preceding and following each spike. This average, termed the revcor, is an estimate of the response of an equivalent linear filter intervening between body motion and spike initiation. The spectrum of the revcor estimates the shape of the equivalent linear filter. Revcor responses were brief, damped oscillations indicative of relatively broadly tuned filters. Filter shapes were generally band-pass and differed in bandwidth, band edge slope, and characteristic frequency (74 Hz to 140 Hz). Filter shapes tend to be independent of stimulus level. Afferents can be placed into two groups with respect to characteristic frequency (74-88 Hz and 140 Hz). Some high-frequency afferents share a secondary peak at the characteristic frequency of low-frequency afferents, suggesting that an afferent may receive differently tuned peripheral inputs. For some afferents having similar filter shapes, revcor responses often differ only in polarity, probably reflecting inputs from hair cells oriented in opposite directions. The origin of frequency selectivity and its diversity among saccular afferents may arise from a combination of hair cell resonance and micromechanical processes. The resulting frequency analysis is the simplest yet observed among vertebrate animals. During courtship, male toadfish produce the 'boatwhistle' call, a periodic vocalization having several harmonics of a 130 Hz fundamental frequency. The saccule encodes the waveform of acoustic particle acceleration between < 50 and about 250 Hz. Thus, the fundamental frequency component of the boatwhistle is well encoded, but the successive higher harmonics are filtered out. The boatwhistle is thus encoded as a time-domain representation of its fundamental frequency or pulse repetition rate.
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directional response properties of saccular afferents of the toadfish Opsanus Tau
Hearing Research, 1997Co-Authors: Richard R. Fay, Peggy L EddswaltonAbstract:The displacement sensitivity, frequency response, and directional response properties of primary saccular afferents of toadfish (Opsanus Tau) were studied in response to a simulation of acoustic particle motion for which displacement magnitudes and directions were manipulated in azimuth and elevation. Stimuli were 50, 100, and 200 Hz sinusoidal, translatory oscillations of the animal at various axes in the horizontal and midsagittal planes. Thresholds in these planes defined a cell's characteristic axis (the axis having the lowest threshold) in spherical coordinates. Recordings were made from afferents in rostral, middle, and caudal bundles of the saccular nerve. The most sensitive saccular afferents responded with a phase-locked response to displacements as small as 0.1 nm. This sensitivity rivals that of the mammalian cochlea and is probably common to the sacculi and other otolith organs of most fishes. Most afferents showed lower thresholds at 100 Hz than at 50 or 200 Hz. Eighty percent of afferents have three-dimensional directional properties that would be expected if they innervated a group of hair cells having the same directional orientation on the saccular epithelium. Of the afferents that are not perfectly directional, most appear to innervate just two groups of hair cells having different orientations. The directional characteristics of afferents are qualitatively correlated with anatomically defined patterns of hair cell orientation on the saccule. In general, azimuths of best sensitivity tend to lie parallel to the plane of the otolith and sensory epithelium. Elevations of best sensitivity correspond well with hair cell orientation patterns in different regions of the saccular epithelium. Directional hearing in the horizontal plane probably depends upon the processing of interaural differences in overall response magnitude. These response differences arise from the gross orientations of the sacculi and are represented, in part, as time differences among nonspontaneous afferents that show level-dependent phase angles of synchronization. Directional hearing in the vertical plane may be derived from the processing of across-afferent profiles of activity within each saccule. Fishes were probably the first vertebrates to solve problems in sound source localization, and we suggest that their solutions formed a model for those of their terrestrial inheritors.
Michael L Fine - One of the best experts on this subject based on the ideXlab platform.
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wall structure and material properties cause viscous damping of swimbladder sounds in the oyster toadfish Opsanus Tau
Proceedings of The Royal Society B: Biological Sciences, 2016Co-Authors: Michael L Fine, Terrence L King, Heba Ali, Nehan Sidker, Timothy M CameronAbstract:Despite rapid damping, fish swimbladders have been modelled as underwater resonant bubbles. Recent data suggest that swimbladders of sound-producing fishes use a forced rather than a resonant response to produce sound. The reason for this discrepancy has not been formally addressed, and we demonstrate, for the first time, that the structure of the swimbladder wall will affect vibratory behaviour. Using the oyster toadfish Opsanus Tau , we find regional differences in bladder thickness, directionality of collagen layers (anisotropic bladder wall structure), material properties that differ between circular and longitudinal directions (stress, strain and Young9s modulus), high water content (80%) of the bladder wall and a 300-fold increase in the modulus of dried tissue. Therefore, the swimbladder wall is a viscoelastic structure that serves to damp vibrations and impart directionality, preventing the expression of resonance.
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grunt variation in the oyster toadfish Opsanus Tau effect of size and sex
PeerJ, 2015Co-Authors: Michael L Fine, Tyler D WaybrightAbstract:As in insects, frogs and birds, vocal activity in fishes tends to be more developed in males than in females, and sonic swimbladder muscles may be sexually dimorphic, i.e., either larger in males or present only in males. Male oyster toadfish Opsanus Tau L produce a long duration, tonal boatwhistle advertisement call, and both sexes grunt, a short duration more pulsatile agonistic call. Sonic muscles are present in both sexes but larger in males. We tested the hypothesis that males would call more than females by inducing grunts in toadfish of various sizes held in a net and determined incidence of calling and developmental changes in grunt parameters. A small number of fish were recorded twice to examine call repeatability. Both sexes were equally likely to grunt, and grunt parameters (sound pressure level (SPL), individual range in SPL, number of grunts, and fundamental frequency) were similar in both sexes. SPL increased with fish size before leveling off in fish >200 g, and fundamental frequency and other parameters did not change with fish size. Number of grunts in a train, grunt duration and inter-grunt interval were highly variable in fish recorded twice suggesting that grunt parameters reflect internal motivation rather than different messages. Grunt production may explain the presence of well-developed sonic muscles in females and suggests that females have an active but unexplored vocal life.
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acoustical properties of the swimbladder in the oyster toadfish Opsanus Tau
The Journal of Experimental Biology, 2009Co-Authors: Michael L Fine, Charles Brian King, Timothy M CameronAbstract:Both the swimbladder and sonic muscles of the oyster toadfish Opsanus Tau (Linnaeus) increase in size with fish growth making it difficult to distinguish their relative contributions to sound production. We examined acoustics of the swimbladder independent of the sonic muscles by striking it with a piezoelectric impact hammer. Amplitude and timing characteristics of bladder sound and displacement were compared for strikes of different amplitudes. Most of the first cycle of sound occurred during swimbladder compression, indicating that the bladder rapidly contracted and expanded as force increased during the strike. Harder hits were shorter in duration and generated a 30 dB increase in amplitude for a 5-fold or 14 dB range in displacement. For an equivalent strike dominant frequency, damping, bladder displacement and sound amplitude did not change with fish size, i.e. equal input generated equal output. The frequency spectrum was broad, and dominant frequency was driven by the strike and not the natural frequency of the bladder. Bladder displacement decayed rapidly (ζ averaged 0.33, equivalent to an automobile shock absorber), and the bladder had a low Q (sharpness of tuning), averaging 1.8. Sound output of an acoustic source is determined by volume velocity (surface area × velocity), and bladder surface area, muscle dimensions and contraction amplitude increase with fish size. Therefore, larger fish will be capable of producing more intense sound. Because the bladder is a low Q resonator, its output will follow muscle contraction rates independent of its size and natural frequency.
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Does muscle fatigue limit advertisement calling in the oyster toadfish Opsanus Tau
Animal Behaviour, 2008Co-Authors: Steve L. Mitchell, J. L. Poland, Michael L FineAbstract:Many sonic fishes appear to produce advertisement calls at a lower rate than insects, frogs and birds (song). Fish sonic muscles in many species rank among the fastest in vertebrates, suggesting that acoustic signalling is a costly activity. Surprisingly however, sound production in the oyster toadfish Opsanus Tau requires negligible oxygen consumption. Male toadfish produce a long-duration tonal advertisement call, the boatwhistle, and both sexes produce short-duration agonistic grunt calls. The question of what limits the calling activity in fishes has not been addressed. We tested the hypothesis that calling in the oyster toadfish is limited by fatigue of the sonic muscles by stimulating them intermittently at the most rapid rate evoked by playbacks of the courtship boatwhistle call (100 ms every 4 s at 200 Hz = 1.5 s stimulation/min) for 5 min and measured swimbladder movement, sound production and glycogen use. Muscles in both sexes showed almost complete fatigue by 5 min (7.5 s of stimulation), although rested control muscles contained over twice as much glycogen in males as in females. Glycogen use was similar in both sexes, but males used 10.8% of their glycogen and females used 23.2%. Glycogen would support muscle contraction at this rate for 15 min in males during mating call production. It appears that sound production in the oyster toadfish is fatigue limited, which dictates a low rate of spontaneous calling that can be elevated for brief bursts of activity.
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metabolic costs of sound production in the oyster toadfish Opsanus Tau
Canadian Journal of Zoology, 2002Co-Authors: Maria Clara Pessoa Amorim, Marti Mccracken, Michael L FineAbstract:The energetics of mate calling has been studied in insects, frogs, birds, and mammals, but not in fishes. The oyster toadfish, Opsanus Tau, produces a boatwhistle advertisement call using one of the fastest muscles known in vertebrates. Because toadfish will not boatwhistle in a respirometer, we measured oxygen consumption after eliciting sound production by electrically stimulating the sonic swim bladder muscle nerve. Induced sounds were similar to a male calling at a rapid rate. Stimulation of the sonic nerve increased the respiration rate by 4060% in males, but they became agitated. Repeating the experiment decreased agitation, and in most fish respiration rates approximated control levels by the second or third replication. Elicited sounds and therefore sonic-muscle performance were similar in all repetitions, hence it appears that the increased oxygen consumption in the first trial was caused by the fish's agitation. Controls indicated that electrode implantation and electrical stimulation of the bo...