scholarly journals Motor behaviour selectively inhibits hair cells activated by forward motion in the lateral line of Zebrafish

2019 ◽  
Author(s):  
Paul Pichler ◽  
Leon Lagnado
Keyword(s):  
Motor Neurons ◽  
Lateral Line ◽  
Hair Cells ◽  
Glutamate Release ◽  
Selective Inhibition ◽  
External World ◽  
The Body ◽  
Motor Behaviour ◽  
Cellular Mechanisms ◽  
Pressure Changes

SummaryHow do sensory systems disambiguate events in the external world from signals generated by the motor behaviour of the animal? One strategy is to suppress the sensory input whenever the motor system is active, but the cellular mechanisms remain unclear. We investigated how motor behaviour modulates signals transmitted by the lateral line of zebrafish, which senses pressure changes around the body of the animal. Activation of motor neurons during fictive swimming caused co-activation of efferent fibers and suppression of synaptic transmission from the primary mechanoreceptors, the hair cells. In some hair cells, a single motor spike inhibited glutamate release by about 50% and block was often complete within 50-100 ms of the start of swimming. All hair cells polarized to be activated by posterior deflections, as would occur during forward swimming, were suppressed by >90%, while only half of those polarized in the anterior direction were inhibited and by an average of just 45%. The selective inhibition of hair cells activated during motor behaviour provides a mechanism for the suppression of self-generated signals while maintaining sensitivity to stimuli originating in the external world.

scholarly journals Hair cells with heterogeneous transfer characteristics encode mechanical stimuli in the lateral line of zebrafish

2018 ◽  
Author(s):  
Paul Pichler ◽  
Leon Lagnado
Keyword(s):  
Lateral Line ◽  
Hair Cells ◽  
Glutamate Release ◽  
Mechanical Stimuli ◽  
Initial Stimulus ◽  
Transfer Characteristics ◽  
Preferred Direction ◽  
Ribbon Synapses ◽  
Mechanical Information ◽  
Unique Signal

Ribbon synapses of hair cells transmit mechanical information but the transfer characteristics relating deflection of the hair bundle to glutamate release have not been assessed directly. Here we have imaged glutamate to investigate how hair cells encode information in the lateral line of zebrafish. Half the hair cells signalled cupula motion in either direction from rest, achieving maximum sensitivity for deflections of ~40 nm in the preferred direction. The remainder rectified completely and were less sensitive, extending the operating range of the neuromast beyond 1μm. Adaptation was also heterogeneous, with some hair cells generating sustained synaptic outputs and others transient. A unique signal encoded a return to rest: a transient burst from hair cells unresponsive to the initial stimulus. A mixed population of hair cells with these various transfer characteristics will allow a neuromast to encode weak stimuli as well as the amplitude and duration of stronger deflections.

scholarly journals A Xenopus neuromast bioassay for chemical ototoxicity

2022 ◽  
Author(s):  
V. Bleu Knight ◽  
Amanda R. Luna ◽  
Elba Serrano
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells ◽  
Experimental Manipulation ◽  
The Body ◽  
Therapeutic Drug ◽  
Sem Images ◽  
Irreversible Damage ◽  
Mechanosensory Hair Cells

Background: Ototoxic chemicals can impair the senses of hearing and balance in mammals through irreversible damage to the mechanosensory bundles of inner ear hair cells. Fish and amphibians are useful models for investigating ototoxicity because their inner ear hair cells, like those of mammals, are susceptible to damage by ototoxins. Moreover, amphibian mechanosensation is augmented by a lateral line organ on the body surface that comprises external mechanosensory hair cells. The lateral line hair cells are arranged in clusters (neuromasts) and are structurally and functionally similar to inner ear hair cells, but are more accessible for experimental manipulation. Herein, we implemented neuromasts of the amphibian (Xenopus) lateral line as an organ system for evaluating the effects of ototoxic chemicals, such as antibiotics, on mechanosensory hair cell bundles. Methods: We examined the ultrastructure of larval Xenopus laevis neuromasts with scanning electron microscopy (SEM) after larvae were continuously exposed to ototoxic aminoglycoside antibiotics at sub-lethal concentrations (gentamicin; streptomycin; neomycin) for 72 hours. Results: SEM images demonstrated that 72 hours of exposure to antibiotic concentrations greater than 25 μM reduced the hair cell bundle number in lateral line neuromasts. Conclusion: Therapeutic drug studies will benefit from the incorporation of bioassay strategies that evaluate ototoxicity across multiple species including genera of amphibian origin such as Xenopus. Our outcomes support the use of the Xenopus lateral line for identification of potential ototoxic chemicals and suggest that Xenopus neuromast hair cell bundles can withstand antibiotic exposure. The Xenopus bioassay presented here can be incorporated into drug discovery methodology as a high-resolution phenotypic screen for ototoxic effects.

The fine structure of the lateral-line sense organs of dogfish

1971 ◽  
Vol 179 (1055) ◽  
pp. 157-169 ◽  
Keyword(s):  
Hair Cell ◽  
Lateral Line ◽  
Hair Cells ◽  
Sensory Cell ◽  
Sensory Nerve ◽  
The Body ◽  
Apical Surface ◽  
Sense Organs ◽  
Supporting Cells ◽  
Efferent Nerve

The sense organs of the body lateral-line canals of Scyliorhinus were examined with the electron microscope and shown to consist of supporting cells and two kinds of sensory cell. One type of sensory cell has the well-known structure of hair cells, bearing on its apical surface a group of stereocilia (6 to 25) associated with a single kinocilium. Each hair cell is innervated by a sensory nerve fibre and some also receive an efferent nerve supply. The second kind of sensory cell is similar in appearance, but differs at the apex in containing many vacuoles and in lacking stereocilia. There are many long microvilli and a single cilium which arises from a shallow pit. The internal structure of this cilium is variable, with the number of tubules in the outer ring ranging between 7 and 9 and with the inner pair consisting of double elements. This type of sensory cell is innervated by sensory nerve fibres and possibly by efferent fibres. The situation of the kinocilium of a hair cell in relation to the stereocilia is more variable than has been described in other hair cells while the cilium of the second sensory cell appears to bear no special relation to the microvilli. The accessory cells of the neuromast include basal and peripheral supporting cells, many of which produce a secretion, and a large secretory cell which is found at intervals at the edge of the organ. This cell has a convoluted surface and is full of vesicles.

scholarly journals Skeletal Muscle Metabolism: Origin or Prognostic Factor for Amyotrophic Lateral Sclerosis (ALS) Development?

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1449
Author(s):  
Cyril Quessada ◽  
Alexandra Bouscary ◽  
Frédérique René ◽  
Cristiana Valle ◽  
Alberto Ferri ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amyotrophic Lateral Sclerosis ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Muscle Metabolism ◽  
The Body ◽  
Energy Deficit ◽  
Acid Oxidation ◽  
Progression Of Disease ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive and selective loss of motor neurons, amyotrophy and skeletal muscle paralysis usually leading to death due to respiratory failure. While generally considered an intrinsic motor neuron disease, data obtained in recent years, including our own, suggest that motor neuron protection is not sufficient to counter the disease. The dismantling of the neuromuscular junction is closely linked to chronic energy deficit found throughout the body. Metabolic (hypermetabolism and dyslipidemia) and mitochondrial alterations described in patients and murine models of ALS are associated with the development and progression of disease pathology and they appear long before motor neurons die. It is clear that these metabolic changes participate in the pathology of the disease. In this review, we summarize these changes seen throughout the course of the disease, and the subsequent impact of glucose–fatty acid oxidation imbalance on disease progression. We also highlight studies that show that correcting this loss of metabolic flexibility should now be considered a major goal for the treatment of ALS.

Whole body withdrawal circuit and its involvement in the behavioral hierarchy of the mollusk Clione limacina

1996 ◽  
Vol 75 (2) ◽  
pp. 529-537 ◽  
Author(s):  
T. P. Norekian ◽  
R. A. Satterlie
Keyword(s):  
Feeding Behavior ◽  
Motor Neurons ◽  
Prey Capture ◽  
The Body ◽  
Whole Body ◽  
High Threshold ◽  
Behavioral Repertoire ◽  
Withdrawal Behavior ◽  
Cerebral Neurons ◽  
Clione Limacina

1. The behavioral repertoire of the holoplanktonic pteropod mollusk Clione limacina includes a few well-defined behaviors organized in a priority sequence. Whole body withdrawal takes precedence over slow swimming behavior, whereas feeding behavior is dominant over withdrawal. In this study a group of neurons is described in the pleural ganglia, which controls whole body withdrawal behavior in Clione. Each pleural withdrawal (Pl-W) neuron has a high threshold for spike generation and is capable of inducing whole body withdrawal in a semi-intact preparation: retraction of the body-tail, wings, and head. Each Pl-W neuron projects axons into the main central nerves and innervates all major regions of the body. 2. Stimulation of Pl-W neurons produces inhibitory inputs to swim motor neurons that terminate swimming activity in the preparation. In turn, Pl-W neurons receive inhibitory inputs from the cerebral neurons involved in the control of feeding behavior in Clione, neurons underlying extrusion of specialized prey capture appendages. Thus it appears that specific inhibitory connections between motor centers can explain the dominance of withdrawal behavior over slow swimming and feeding over withdrawal in Clione.

scholarly journals Anion Exchanger 1b in Stereocilia Is Required for the Functioning of Mechanotransducer Channels in Lateral-Line Hair Cells of Zebrafish

PLoS ONE ◽  
2015 ◽  
Vol 10 (2) ◽  
pp. e0117041 ◽  
Author(s):  
Yuan-Hsiang Lin ◽  
Giun-Yi Hung ◽  
Liang-Chun Wu ◽  
Sheng-Wen Chen ◽  
Li-Yih Lin ◽  
...  
Keyword(s):  
Lateral Line ◽  
Hair Cells ◽  
Anion Exchanger

Characterization of Myoelectric Signals Using System Identification Techniques

2004 ◽  
Author(s):  
Jeffrey T. Bingham ◽  
Marco P. Schoen
Keyword(s):  
System Identification ◽  
Motor Neurons ◽  
Current System ◽  
Electrical Potential ◽  
Computer Software ◽  
The Body ◽  
Myoelectric Signals ◽  
Hand Motion ◽  
The Central Nervous System

Human muscle motion is initiated in the central nervous system where a nervous signal travels through the body and the motor neurons excite the muscles to move. These signals, termed myoelectric signals, can be measured on the surface of the skin as an electrical potential. By analyzing these signals it is possible to determine the muscle actions the signals elicit, and thus can be used in manipulating smart prostheses and teleoperation of machinery. Due to the randomness of myoelectric signals, identification of the signals is not complete, therefore the goal of this project is to complete a study of the characterization of one set of hand motions using current system identification methods. The gripping motion of the hand and the corresponding myoelectric signals are measured and the data captured with a personal computer. Using computer software the captured data are processed and finally subjected to several system identification routines. Using this technique it is possible to construct a mathematical model that correlates the myoelectric signals with the matching hand motion.

S-100 protein is a selective marker for sensory hair cells of the lateral line system in teleosts

2002 ◽  
Vol 329 (2) ◽  
pp. 133-136 ◽  
Author(s):  
F Abbate ◽  
S Catania ◽  
A Germanà ◽  
T González ◽  
B Diaz-Esnal ◽  
...  
Keyword(s):  
Lateral Line ◽  
Hair Cells ◽  
Lateral Line System ◽  
Selective Marker ◽  
Line System ◽  
Sensory Hair ◽  
Sensory Hair Cells ◽  
S 100

Changes in Blood Pressure, Heart Rate and Breathing Rate During Moderate Swimming Activity in Rainbow Trout

1967 ◽  
Vol 46 (2) ◽  
pp. 307-315 ◽  
Author(s):  
E. DON STEVENS ◽  
D. J. RANDALL
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Rainbow Trout ◽  
Venous Blood ◽  
The Body ◽  
Swimming Activity ◽  
Breathing Rate ◽  
Blood Pressures ◽  
Ventral Aorta ◽  
Pressure Changes

1. Changes in blood pressure in the dorsal aorta, ventral aorta and subintestinal vein, as well as changes in heart rate and breathing rate during moderate swimming activity in the rainbow trout are reported. 2. Blood pressures both afferent and efferent to the gills increased during swimming and then returned to normal levels within 30 min. after exercise. 3. Venous blood pressure was characterized by periodic increases during swimming. The pressure changes were not in phase with the body movements. 4. Although total venous return to the heart increased during swimming, a decreased blood flow was recorded in the subintestinal vein. 5. Heart rate and breathing rate increased during swimming and then decreased when swimming ceased. 6. Some possible mechanisms regulating heart and breathing rates are discussed.

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