Frequency Response Properties of Lateral Line Superficial Neuromasts in a Vocal Fish, With Evidence for Acoustic Sensitivity

2002 ◽  
Vol 88 (3) ◽  
pp. 1252-1262 ◽  
Author(s):  
Matthew S. Weeg ◽  
Andrew H. Bass

The mechanosensory lateral line of fish is a hair cell based sensory system that detects water motion using canal and superficial neuromasts. The trunk lateral line of the plainfin midshipman fish, Porichthys notatus, only has superficial neuromasts. The posterior lateral line nerve (PLLn) therefore innervates trunk superficial neuromasts exclusively and provides the opportunity to investigate the physiological responses of these receptors without the confounding influence of canal organs. We recorded single-unit activity from PLLn primary afferents in response to a vibrating sphere stimulus calibrated to produce an equal velocity across frequencies. Threshold tuning, isovelocity, and input/output curves were constructed using spike rate and vector strength, a measure of phase locking of spike times to the stimulus waveform. All units responded maximally to frequencies of 20–50 Hz. Units were classified as low-pass, band-pass, broadly tuned, or complex based on the shapes of tuning and isovelocity curves between 20 and 100 Hz. A 100 Hz stimulus caused an increase in spike rate in almost 50%, and significant synchronization in >80%, of all units. Midshipman vocalizations contain significant energy at and below 100 Hz, so these results demonstrate that the midshipman peripheral lateral line system can encode these acoustic signals. These results provide the first direct demonstration that units innervating superficial neuromasts in a teleost fish have heterogeneous frequency response properties, including an upper range of sensitivity that overlaps spectral peaks of behaviorally relevant acoustic stimuli.

2015 ◽  
Vol 113 (2) ◽  
pp. 657-668 ◽  
Author(s):  
Rafael Levi ◽  
Otar Akanyeti ◽  
Aleksander Ballo ◽  
James C. Liao

The ability of fishes to detect water flow with the neuromasts of their lateral line system depends on the physiology of afferent neurons as well as the hydrodynamic environment. Using larval zebrafish ( Danio rerio), we measured the basic response properties of primary afferent neurons to mechanical deflections of individual superficial neuromasts. We used two types of stimulation protocols. First, we used sine wave stimulation to characterize the response properties of the afferent neurons. The average frequency-response curve was flat across stimulation frequencies between 0 and 100 Hz, matching the filtering properties of a displacement detector. Spike rate increased asymptotically with frequency, and phase locking was maximal between 10 and 60 Hz. Second, we used pulse train stimulation to analyze the maximum spike rate capabilities. We found that afferent neurons could generate up to 80 spikes/s and could follow a pulse train stimulation rate of up to 40 pulses/s in a reliable and precise manner. Both sine wave and pulse stimulation protocols indicate that an afferent neuron can maintain their evoked activity for longer durations at low stimulation frequencies than at high frequencies. We found one type of afferent neuron based on spontaneous activity patterns and discovered a correlation between the level of spontaneous and evoked activity. Overall, our results establish the baseline response properties of lateral line primary afferent neurons in larval zebrafish, which is a crucial step in understanding how vertebrate mechanoreceptive systems sense and subsequently process information from the environment.


Zoomorphology ◽  
2020 ◽  
Author(s):  
Harald Ahnelt ◽  
David Ramler ◽  
Maria Ø. Madsen ◽  
Lasse F. Jensen ◽  
Sonja Windhager

AbstractThe mechanosensory lateral line of fishes is a flow sensing system and supports a number of behaviors, e.g. prey detection, schooling or position holding in water currents. Differences in the neuromast pattern of this sensory system reflect adaptation to divergent ecological constraints. The threespine stickleback, Gasterosteus aculeatus, is known for its ecological plasticity resulting in three major ecotypes, a marine type, a migrating anadromous type and a resident freshwater type. We provide the first comparative study of the pattern of the head lateral line system of North Sea populations representing these three ecotypes including a brackish spawning population. We found no distinct difference in the pattern of the head lateral line system between the three ecotypes but significant differences in neuromast numbers. The anadromous and the brackish populations had distinctly less neuromasts than their freshwater and marine conspecifics. This difference in neuromast number between marine and anadromous threespine stickleback points to differences in swimming behavior. We also found sexual dimorphism in neuromast number with males having more neuromasts than females in the anadromous, brackish and the freshwater populations. But no such dimorphism occurred in the marine population. Our results suggest that the head lateral line of the three ecotypes is under divergent hydrodynamic constraints. Additionally, sexual dimorphism points to divergent niche partitioning of males and females in the anadromous and freshwater but not in the marine populations. Our findings imply careful sampling as an important prerequisite to discern especially between anadromous and marine threespine sticklebacks.


2017 ◽  
Vol 51 (5) ◽  
pp. 103-115 ◽  
Author(s):  
Kevin Nelson ◽  
Kamran Mohseni

AbstractThis paper presents a sensory system that is biologically inspired by the lateral line sensory system found in fish. This artificial lateral line system provides sensory information to be used in vehicle control algorithms, both to reduce model complexity and to measure hydrodynamic disturbances. The system presented in this paper is a modular implementation that can fit around a vehicle without requiring modifications to the hull. The design and manufacturing processes are presented in detail along with considerations for sensor placement and port spacing. An algorithm for calculating the hydrodynamic forces acting on the surface of a vehicle is derived and experimentally validated. An underwater motion capture system and strain sensors are used to calculate a reference hydrodynamic force that compares favorably with the hydrodynamic force calculated by the lateral line system.


For a long time after their discovery in the seventeenth century the lateral-line canals of fishes were considered to be mucus-secreting organs. In 1850 Leydig described sense organs in the lateral-line canals, and this discovery stimulated a keen interest in the investigation of both the morphological and functional features of the lateral-line system. Morphological studies have yielded a thorough understanding of the structure of these organs (Ewart and Mitchell 1892; Cole 1896; Johnson 1917; von Woellwarth 1933). Physiological studies, though numerous, have been less fruitful. An account of the older work was given by Baglioni (1913), and the more recent work is reviewed by Dykgraaf (1933). The only technique until recently available has been the elimination of the sensory system by nerve section and cauterization, and the comparison of the behaviour of intact and operated fishes in response to various stimuli. With so diffuse a structure as the lateral-line system, receiving its nerve supply from the fifth, seventh, ninth and tenth cranial nerves, this method is particularly inadequate, and involves a violent mutilation of the animal. When one considers the crudity of many of these operations, it is not the uncertainty of the results which is remarkable, but rather that some of the conclusions reached should remain valid to-day in the light of far more penetrating experimental analysis. This method of organ elimination could yield at best only an indication of the kind of stimulus that is effective in evoking the excitation of lateral-line receptors. In current textbooks the conclusion of Parker (1904) that the effective stimulus for the lateral line is low-frequency vibration, and that of Hofer (1907) that it is movement of water (i. e. local currents) have received most notice. The observations of Dykgraaf (1933), who employed the more refined methods of von Frisch’s futterdressur technique, support Hofer’s conclusion, and to some extent also Parker’s. Dykgraaf considers the lateral-line system to be an organ of Ferntastsinn , and if this is taken to mean a mechanoreceptor of such sensitivity that it can function both as a touch organ and as a receptor for disturbances coming from a distance, it is undoubtedly a true description, for it is fully confirmed by the direct electrophysiological studies of Hoagland (1933 a, b, c and d ) and of Schriever (1935). The latter, apparently unacquainted with Hoagland’s work, did little more than to confirm several of his observations.


2014 ◽  
Vol 112 (6) ◽  
pp. 1329-1339 ◽  
Author(s):  
Melanie Haehnel-Taguchi ◽  
Otar Akanyeti ◽  
James C. Liao

The lateral line system of fishes contains mechanosensory receptors along the body surface called neuromasts, which can detect water motion relative to the body. The ability to sense flow informs many behaviors, such as schooling, predator avoidance, and rheotaxis. Here, we developed a new approach to stimulate individual neuromasts while either recording primary sensory afferent neuron activity or swimming motoneuron activity in larval zebrafish ( Danio rerio). Our results allowed us to characterize the transfer functions between a controlled lateral line stimulus, its representation by primary sensory neurons, and its subsequent behavioral output. When we deflected the cupula of a neuromast with a ramp command, we found that the connected afferent neuron exhibited an adapting response which was proportional in strength to deflection velocity. The maximum spike rate of afferent neurons increased sigmoidally with deflection velocity, with a linear range between 0.1 and 1.0 μm/ms. However, spike rate did not change when the cupula was deflected below 8 μm, regardless of deflection velocity. Our findings also reveal an unexpected sensitivity in the larval lateral line system: stimulation of a single neuromast could elicit a swimming response which increased in reliability with increasing deflection velocities. At high deflection velocities, we observed that lateral line evoked swimming has intermediate values of burst frequency and duty cycle that fall between electrically evoked and spontaneous swimming. An understanding of the sensory capabilities of a single neuromast will help to build a better picture of how stimuli are encoded at the systems level and ultimately translated into behavior.


1950 ◽  
Vol 34 (1) ◽  
pp. 1-8 ◽  
Author(s):  
E. E. Suckling ◽  
J. A. Suckling

1. The lateral line of Fundulus heteroclitus and Fundulus majalis is shown to react to tone at an intensity level of 20 dynes per sq. cm. at frequencies up to 200 or 300 cycles per second. 2. Evidence is given that the nerve can reproduce the stimulating tone frequency up to at least 180 cycles per second. 3. The response of the lateral line to the swimming movements of nearby fish is demonstrated. 4. Fundulus and several other species are shown to give strong spontaneous activity of the lateral line nerve.


2012 ◽  
Vol 107 (10) ◽  
pp. 2581-2593 ◽  
Author(s):  
Julie Goulet ◽  
J. Leo van Hemmen ◽  
Sarah N. Jung ◽  
Boris P. Chagnaud ◽  
Björn Scholze ◽  
...  

Fish and aquatic frogs detect minute water motion by means of a specialized mechanosensory system, the lateral line. Ubiquitous in fish, the lateral-line system is characterized by hair-cell based sensory structures across the fish's surface called neuromasts. These neuromasts occur free-standing on the skin as superficial neuromasts (SN) or are recessed into canals as canal neuromasts. SNs respond to rapid changes of water velocity in a small layer of fluid around the fish, including the so-called boundary layer. Although omnipresent, the boundary layer's impact on the SN response is still a matter of debate. For the first time using an information-theoretic approach to this sensory system, we have investigated the SN afferents encoding capabilities. Combining covariance analysis, phase analysis, and modeling of recorded neuronal responses of primary lateral line afferents, we show that encoding by the SNs is adequately described as a linear, velocity-responsive mechanism. Afferent responses display a bimodal distribution of opposite Wiener kernels that likely reflected the two hair-cell populations within a given neuromast. Using frozen noise stimuli, we further demonstrate that SN afferents respond in an extremely precise manner and with high reproducibility across a broad frequency band (10–150 Hz), revealing that an optimal decoder would need to rely extensively on a temporal code. This was further substantiated by means of signal reconstruction of spike trains that were time shifted with respect to their original. On average, a time shift of 3.5 ms was enough to diminish the encoding capabilities of primary afferents by 70%. Our results further demonstrate that the SNs' encoding capability is linearly related to the stimulus outside the boundary layer, and that the boundary layer can, therefore, be neglected while interpreting lateral line response of SN afferents to hydrodynamic stimuli.


1995 ◽  
Vol 198 (12) ◽  
pp. 2581-2591 ◽  
Author(s):  
T G Deliagina ◽  
F Ullén ◽  
M-J. Gonzalez ◽  
H Ehrsson ◽  
G N Orlovsky ◽  
...  

The lateral line system of lampreys includes photoreceptors distributed in the skin of the tail region. These are innervated by the trunk lateral line nerves, and the afferents terminate bilaterally in the medial octavolateral nucleus, crossing the midline through the cerebellar commissure. Stimulation of the dermal photoreceptors by tail illumination initiates locomotion. The present study was performed to characterize the response to illumination in larval and adult lampreys in detail and to elucidate the neuronal pathways responsible for the activation of locomotion. In both larval and adult quiescent lampreys, the response to unilateral illumination of the tail was found to consist of an initial turn followed by rectilinear swimming. The sign and magnitude of the turning angle were not correlated with the laterality of the optic stimulus. In mechanically restrained lampreys, spinalized at the level of segments 15­20, tail illumination evoked a complex motor response in the rostral part of the body, with switches between different patterns of coordination (turns in different directions, locomotion, and turns combined with locomotion). Thus, the response to tail illumination is not a simple reflex, but includes a behavioural choice. Reticulospinal neurones play a crucial role in the initiation of locomotion in lampreys. The response to unilateral tail illumination in rhombencephalic reticular cells was studied with extracellular single-unit recordings. It was found that neurones in the middle and posterior rhombencephalic reticular nuclei were activated bilaterally. Tonic activity or slow bursts (<0.5 Hz) were evoked, in some cases lasting up to 60 s after the stimulation. The response remained bilateral after transection of one lateral line nerve and the cerebellar commissure. Afferents from one side can thus activate reticulospinal cells on both sides through a pathway outside the cerebellar commissure. This bilateral activation of reticulospinal neurones is presumably responsible for the activation of spinal locomotor networks, without any directional bias to the left or the right side, and for the rectilinear swimming observed in behavioural experiments. In the caudal part of the termination area of the lateral line nerve afferents, neurones with contralateral projections were retrogradely stained with horseradish peroxidase. These neurones appear to be likely candidates for mediating the contralateral effects of the lateral line fibres.


Author(s):  
T. S. Kemp

‘The amphibians’ world’ focuses on the amphibians’ sense organs. Amphibians have the eyes, ears, olfactory organs of smell in the nose, and touch receptors common to all vertebrates, but the relative importance of the different senses varies from group to group depending on habitats and modes of life. Anurans have a sensory world most like that of humans; their vision is good, and includes the ability to see colours, and their hearing is acute. Urodeles and caecilians rely much more on their senses of smell and touch. Amphibian larvae have an additional sensory system called the lateral line system. Amphibians use several sensory cues in combination to navigate around their territories.


1934 ◽  
Vol 18 (1) ◽  
pp. 89-91 ◽  
Author(s):  
Hudson Hoagland

Records of spontaneous discharge of nerve impulses, similar to that previously described in catfish and in trout, have been obtained from lateral-line nerves of goldfish and perch, by the use of concentric micro electrodes slipped under the nerve in situ. These impulses have been followed into the central nervous system. They enter the tuberculum acusticum and thence apparently spread diffusely through the cerebellum. Cutting the lateral-line nerve on one side silences the ipsilateral tuberculum acusticum, but only reduces the intensity of ipsilateral cerebellar activity. Cutting the remaining lateral-line nerve silences activity throughout the tuberculum acusticum and the cerebellum. The maintenance of tonic activity in the tuberculum acusticum by way of lateral-line discharge may account for the inhibitory effects of the lateral-line system on auditory responses.


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