Hindbrain signal processing in the lateral line system of the dwarf scorpionfish Scopeana papillosus

1996 ◽  
Vol 199 (4) ◽  
pp. 893-899 ◽  
Author(s):  
J Montgomery ◽  
D Bodznick ◽  
M Halstead

Recordings were made from primary afferent fibres and secondary projection neurones (crest cells) in the mechanosensory lateral line system of the dwarf scorpionfish. Crest cells were identified by antidromic stimulation from the contralateral midbrain. Differences between primary afferent fibre and crest cell response characteristics are indicative of signal processing by the neuronal circuitry of the medial octavolateralis nucleus. There are a number of differences between primary afferent fibres and crest cells. Primary afferents have relatively high levels of spontaneous activity (mean close to 40 impulses s-1) and many of them are strongly modulated by ventilation. By contrast, crest cells have a much lower rate of spontaneous activity that is not obviously modulated by ventilation. Primary afferents show a simple tonic response to a maintained stimulus, whereas crest cells show a variety of temporal response properties, but in general show a phasic/tonic response to the same prolonged stimulus. Afferents are most sensitive to frequencies of stimulation around 100 Hz; in contrast, crest cells show a strong suppression of activity at this frequency. Crest cells are most responsive around 50 Hz. These afferent/secondary comparisons show similarities with those reported for allied electrosensory and auditory pathways.

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.


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.


2021 ◽  
Author(s):  
Qiuxiang Zhang ◽  
Katie Kindt

Hair cells are the sensory receptors in the auditory and vestibular systems of all vertebrates, and in the lateral-line system of aquatic vertebrates. During development, spontaneous activity in hair cells shapes the formation of these sensory systems. In auditory hair cells of mice, coordinated waves of spontaneous activity can be triggered by concomitant activity in nearby supporting cells. But in mammals, developing auditory and vestibular hair cells can also autonomously generate spontaneous events independent of supporting cell activity. To date, significant progress has been made studying spontaneous activity in the auditory and vestibular systems of mammals, in isolated cultures. The purpose of this work is to explore the zebrafish lateral-line system as a model to study and understand spontaneous activity in vivo. Our work applies genetically encoded calcium indicators along with light-sheet fluorescence microscopy to visualize spontaneous calcium activity in the developing lateral-line system. Consistent with our previous work, we show that spontaneous calcium activity is present in developing lateral-line hair cells. We now show that supporting cells that surround hair cells, and cholinergic efferent terminals that directly contact hair cells are also spontaneously active. Using two-color functional imaging we demonstrate that spontaneous activity in hair cells does not correlate with activity in either supporting cells or cholinergic terminals. We find that during lateral-line development, hair cells autonomously generate spontaneous events. Using localized calcium indicators, we show that within hair cells, spontaneous calcium activity occurs in two distinct domains-the mechanosensory bundle and the presynapse. Further, spontaneous activity in the mechanosensory bundle ultimately drives spontaneous calcium influx at the presynapse. Comprehensively, our results indicate that in developing lateral-line hair cells, autonomously generated spontaneous activity originates with spontaneous mechanosensory events. Overall, with robust spontaneous activity three different cell types, the developing lateral line is a rich model to study these activities in an intact sensory organ. Future work studying this model may further our understanding of these activities and their role in sensory system formation, function and regeneration.


1977 ◽  
Vol 195 (1121) ◽  
pp. 479-496 ◽  

Field potentials and unit discharges generated by electrical stimulation of the anterior lateral-line nerves were recorded from the ipsilateral lateral-line lobes of the hindbrain of decerebrate dogfish. They were absent from the cerebellar corpus and the contralateral hindbrain. The field potentials were positive-going within the molecular layer and negative-going in the underlying dorsal nucleus. They were preceded by compound action potentials of sensory fibres and of antidromically activated lateral-line efferent neurones. The earliest part of the main field probably represents the monosynaptic activation of second-order afferent cell bodies. It was closely followed by the antidromic invasion of the cell bodies and dendrites of the efferent neurones. Later portions of the potentials were created by repetitive activity of the second order afferent cells and of the efferent neurones. It is thought that the dendrites of the second order cells propagated active potentials from the cell body into the molecular layer at velocities of about 0.5 m s -1 . The unit discharges were identified as arising from: (i) primary afferent fibres, (ii) second order afferent neurones, and (iii) efferent neurones. Primary afferent fibres, which frequently discharged in phase with respiratory movements, responded vigorously to natural stimulation of the lateral lines of the head. Secondary afferent cells did not show a respiratory rhythm, probably because lateral-line stimulation was followed by a sharp fall in excitability which began 15 ms after the stimulus and lasted for at least 30 ms. Complete recovery from a single lateral­-line stimulus took as long as 100 ms. Some nerve cells, which could follow high-frequency stimulation at short latency without ‘jitter’, also discharged up to 4 later spikes to a single stimulus if stimuli were applied at rates of < 0.3 Hz. This discharge was evidently synaptically derived and would follow higher stimulation frequencies (1 Hz) if presented with paired stimuli. Such neurones must be efferent cells of the lateral-line system.


1933 ◽  
Vol 16 (4) ◽  
pp. 715-732 ◽  
Author(s):  
Hudson Hoagland

1. The lateral-line nerves of trout as well as those of catfish are found to discharge impulses spontaneously at a high frequency. 2. The frequency of nerve impulse discharge is measured as a function of the number of participating receptor groups (lateral-line sense organs). A quantitative analysis is made of the contribution to the total response made by each group of sense organs. 3. An analysis of the variability of the response is presented which makes it possible to estimate quantitatively the longitudinal extent of damage to the neuromasts due to surgical manipulation. 4. A method is described for recording the response of a single nerve fiber in the lateral-line trunk. 5. The frequency of the spontaneous discharge from the lateral-line nerve trunk when plotted as a function of temperature according to the Arrhenius equation yields a temperature characteristic of approximately 5000 calories. 6. The variability of the frequency of response as a function of temperature indicates the existence of temperature thresholds for the spontaneous activity of the neuromasts. 7. A possible basis for the spontaneous activity is considered. It is pointed out that the lateral-line system may serve as a model of the Purkinje cells of the cerebellum.


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.


2006 ◽  
Vol 193 (2) ◽  
pp. 271-277 ◽  
Author(s):  
S. Gelman ◽  
A. Ayali ◽  
E. D. Tytell ◽  
A. H. Cohen

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