II. Post-Tetanic Potentiation and Depression of Generator Potential in a Single Non-Myelinated Nerve Ending

Repetitive activity at the non-myelinated ending of Pacinian corpuscles leaves the following after-effects: (1) With certain parameters of repetitive mechanical stimulation of the ending a depression in generator potential is produced. The effect is fully reversible and has low energy requirements. The effect is a transient decrease in responsiveness of the receptor membrane which is unrelated to changes in resting membrane potential. It appears to reflect an inactivation process of the receptor membrane. Within certain limits, the depression increases as a function of strength, frequency, and train duration of repetitive stimuli. (2) With other, more critical parameters of repetitive stimulation a hyperpolarization of the ending and of the first intracorpuscular Ranvier node may be produced. This leads to respectively post-tetanic potentiation of generator potential and increase in nodal firing threshold. The balance of these after-effects determines the threshold for the production of nerve impulses by adequate (mechanical) stimulation of the sense organ. The after-effects of activity at the node can be elicited by dromic (mechanical) stimulation of the ending, as well as by antidromic (electric) stimulation of the axon; the after-effects at the ending can only be produced by dromic and not by antidromic stimulation.

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Effects of Temperature on the Generator and Action Potentials of a Sense Organ

The Journal of General Physiology ◽

10.1085/jgp.45.1.105 ◽

1961 ◽

Vol 45 (1) ◽

pp. 105-124 ◽

Cited By ~ 54

Author(s):

Nobusada Ishiko ◽

Werner R. Loewenstein

Keyword(s):

Mechanical Stimulation ◽

Sense Organ ◽

Nerve Impulse ◽

Mechanical Stimulus ◽

Ranvier Node ◽

Passive Component ◽

Pacinian Corpuscles ◽

Generator Potential ◽

Receptor Membrane ◽

Wide Range

Charge transfer through the receptor membrane of the nonmyelinated ending of Pacinian corpuscles is markedly affected by temperature. The rate of rise and the amplitude of the generator potential in response to a constant mechanical stimulus increase with temperature coefficients of 2.5 and 2.0 respectively. The duration of the falling phase, presumably a purely passive component, and the rise time of the generator potential are but little affected by temperature. The following interpretation is offered: Mechanical stimulation causes the conductance of the receptor membrane to increase and ions to flow along their electrochemical gradients. An energy barrier of about 16,000 cal/mole limits the conductance change. The latter increases, thus, steeply with temperature, causing both the rate of rise and the intensity of the generator current to increase. The membrane of the adjacent Ranvier node behaves in a distinctly different manner. The amplitude of the nodal action potential is little changed over a wide range of temperature, while the durations of its rising and falling phases increase markedly. The electrical threshold of the nodal membrane is rather constant between 40 and 12°C. Below 12°C the threshold rises, and the mechanically elicited generator current fails to meet the threshold requirements of the first node. Cold block of nerve impulse initiation then ensues, although the receptor membrane still continues to produce generator potentials in response to mechanical stimulation.

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Effects of Polarization of the Receptor Membrane and of the First Ranvier Node in a Sense Organ

The Journal of General Physiology ◽

10.1085/jgp.43.5.981 ◽

1960 ◽

Vol 43 (5) ◽

pp. 981-998 ◽

Cited By ~ 21

Author(s):

W. R. Loewenstein ◽

N. Ishiko

Keyword(s):

Sense Organ ◽

Nerve Impulse ◽

Electric Activity ◽

Resting Potential ◽

Ranvier Node ◽

Mechanical Stimuli ◽

Pacinian Corpuscles ◽

Generator Potential ◽

Receptor Membrane ◽

Refractory State

It has previously been shown that the site of production of the generator potential in Pacinian corpuscles is the receptor membrane of the non-myelinated ending, and the site of initiation of the nerve impulse, the adjacent (first) Ranvier node. Effects of membrane polarization of these sites were studied in the present work. Nerve ending and first Ranvier node were isolated by dissection, electric activity was recorded from, and polarizing currents were passed through them. All observations were done at steady levels of polarization, seconds after onset of current flow. The following results were obtained: The amount of charge transferred through the excited receptor membrane is a function of the electrical gradients across the membrane. The generator potential in response to equal mechanical stimuli increases with resting potential of the receptor membrane. The refractory state of the generator potential is not affected by polarization. The electrical threshold for impulse firing at the first Ranvier node (measured by the minimal amplitude of generator potential which elicits a nodal impulse) is nearly minimal at normal resting potential of the node. Both, hyperpolarization and depolarization lead to a rise in nodal threshold. For any level of polarization of nodal and receptor membrane, the threshold for production of impulses by adequate (mechanical) stimulation appears determined by the generator potential-stimulus strength relation and by the electrical threshold of the node.

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Activity-Dependent Sensitivity of Proprioceptive Sensory Neurons in the Stick Insect Femoral Chordotonal Organ

Journal of Neurophysiology ◽

10.1152/jn.00339.2002 ◽

2002 ◽

Vol 88 (5) ◽

pp. 2387-2398 ◽

Cited By ~ 5

Author(s):

Ralph A. DiCaprio ◽

Harald Wolf ◽

Ansgar Büschges

Keyword(s):

Sensory Neurons ◽

Mechanical Stimulation ◽

Stick Insect ◽

Chordotonal Organ ◽

Afferent Neurons ◽

Generator Potential ◽

Slow Adaptation ◽

Wide Range ◽

Mechanical Factors ◽

Stimulation Of

Mechanosensory neurons exhibit a wide range of dynamic changes in response, including rapid and slow adaptation. In addition to mechanical factors, electrical processes may also contribute to sensory adaptation. We have investigated adaptation of afferent neurons in the stick insect femoral chordotonal organ (fCO). The fCO contains sensory neurons that respond to position, velocity, and acceleration of the tibia. We describe the influence of random mechanical stimulation of the fCO on the response of fCO afferent neurons. The activity of individual sensory neurons was recorded intracellularly from their axons in the main leg nerve. Most fCO afferents (93%) exhibited a marked decrease in response to trapezoidal stimuli following sustained white noise stimulation (bandwidth = 60 Hz, amplitudes from ±5 to ±30°). Concurrent decreases in the synaptic drive to leg motoneurons and interneurons were also observed. Electrical stimulation of spike activity in individual fCO afferents in the absence of mechanical stimulation also led to a dramatic decrease in response in 15 of 19 afferents tested. This indicated that electrical processes are involved in the regulation of the generator potential or encoding of action potentials and partially responsible for the decreased response of the afferents. Replacing Ca2+ with Ba2+ in the saline surrounding the fCO greatly reduced or blocked the decrease in response elicited by electrically induced activity or mechanical stimulation when compared with control responses. Our results indicate that activity of fCO sensory neurons strongly affects their sensitivity, most likely via Ca2+-dependent processes.

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I. After-Effects of Repetitive Activity in a Nerve Ending

The Journal of General Physiology ◽

10.1085/jgp.43.2.335 ◽

1959 ◽

Vol 43 (2) ◽

pp. 335-345 ◽

Cited By ~ 13

Author(s):

Werner R. Loewenstein ◽

Stanley Cohen

Keyword(s):

Mechanical Stimulation ◽

Nerve Ending ◽

Sense Organ ◽

Repetitive Stimulation ◽

Pacinian Corpuscles ◽

After Effects ◽

Nerve Impulses ◽

Mechanical Threshold ◽

Threshold Strength

Repetitive mechanical stimulation causes depression of excitability in isolated Pacinian corpuscles: the mechanical threshold of the sense organ for producing nerve impulses increases progressively with time of repetitive stimulation. The effect is completely reversible; it can be elicited with repetitive stimuli of less than threshold strength. Within certain limits, the depression increases as a function of strength and frequency of the repetitive stimuli.

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Mechanical stimulation of human BON cells: Gαq involvement in 5-HT release

Gastroenterology ◽

10.1016/s0016-5085(01)80410-8 ◽

2001 ◽

Vol 120 (5) ◽

pp. A83-A83

Author(s):

M KIM ◽

N JAVED ◽

F CHRISTOFI ◽

H COOKE

Keyword(s):

Mechanical Stimulation ◽

Bon Cells ◽

Stimulation Of

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Neural mechanisms of hepatic blood flow response to noxious mechanical stimulation of skin in anesthetized rats

Neuroscience Research ◽

10.1016/s0168-0102(00)81890-8 ◽

2000 ◽

Vol 38 ◽

pp. S174

Author(s):

K Enomoto

Keyword(s):

Blood Flow ◽

Hepatic Blood Flow ◽

Mechanical Stimulation ◽

Neural Mechanisms ◽

Blood Flow Response ◽

Flow Response ◽

Anesthetized Rats ◽

Noxious Mechanical Stimulation ◽

Stimulation Of

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Use of Flexible Materials with a Novel Pressure Driven Equibiaxial Cell Stretching Device for Mechanical Stimulation of Single Mammalian Cells

MRS Proceedings ◽

10.1557/proc-773-n5.6 ◽

2003 ◽

Vol 773 ◽

Author(s):

James D. Kubicek ◽

Stephanie Brelsford ◽

Philip R. LeDuc

Keyword(s):

Cell Fate ◽

Mechanical Stimulation ◽

Mammalian Cells ◽

Cellular Response ◽

Single Cells ◽

Complex Nature ◽

Cellular Behavior ◽

Cell Stretching ◽

Stimulation Of ◽

Pressure Driven

AbstractMechanical stimulation of single cells has been shown to affect cellular behavior from the molecular scale to ultimate cell fate including apoptosis and proliferation. In this, the ability to control the spatiotemporal application of force on cells through their extracellular matrix connections is critical to understand the cellular response of mechanotransduction. Here, we develop and utilize a novel pressure-driven equibiaxial cell stretching device (PECS) combined with an elastomeric material to control specifically the mechanical stimulation on single cells. Cells were cultured on silicone membranes coated with molecular matrices and then a uniform pressure was introduced to the opposite surface of the membrane to stretch single cells equibiaxially. This allowed us to apply mechanical deformation to investigate the complex nature of cell shape and structure. These results will enhance our knowledge of cellular and molecular function as well as provide insights into fields including biomechanics, tissue engineering, and drug discovery.

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