Intensity and frequency characteristics of pacinian corpuscles. II. Receptor potentials

1984 ◽  
Vol 51 (4) ◽  
pp. 812-830 ◽  
Author(s):  
S. J. Bolanowski ◽  
J. J. Zwislocki
Keyword(s):  
Firing Rate ◽  
Stimulus Intensity ◽  
Vibration Frequency ◽  
Frequency Characteristic ◽  
Receptor Potential ◽  
Frequency Characteristics ◽  
Pacinian Corpuscles ◽  
Spike Threshold ◽  
Full Wave ◽  
Criterion Response

Intensity characteristics that relate receptor- (generator) potential amplitude to vibration amplitude and frequency characteristics that relate either the stimulus intensity required for a criterion response or the phase angle between the stimulus and the receptor potential to vibration frequency have been obtained from isolated pacinian corpuscles removed from cat mesentery. The intensity characteristics of signal-averaged receptor potentials in response to sinusoidal displacements were found to be linear at low stimulus levels and to saturate at higher ones. At the higher levels, an asymmetric full-wave rectification was often found, the degree of which varied among receptors. The receptor-potential waveforms showed a time-dependent hysteresis in response to every stimulus cycle at moderate and high stimulus levels. An average intensity characteristic is given. The measured amplitude-frequency characteristics for a constant magnitude of the receptor potential below the neural spike threshold were found to be U-shaped functions. The averaged (n = 7) amplitude-frequency characteristic generated at a constant criterion response had a best frequency of 370 Hz and a bandwidth of Q3 dB equal to 0.8. The phase-frequency characteristics of the receptor potentials below spike threshold exhibited two populations of responses. Both populations underwent phase changes of about 300 degrees as the vibration frequency was increased from 20 Hz to 1.0 kHz but were separated by 180 degrees. An average (n = 8) phase-frequency characteristic is shown. For a constant neural firing rate, the relationship between receptor-potential amplitude and stimulus frequency was also U-shaped. Several qualitative physiological models are presented in relation to previously reported anatomical evidence (14, 18, 19, 32, 45). For the intensity domain, it is suggested that the cytoplasmic extensions that protrude from the unmyelinated portion of the corpuscle axon into the hemilamellar clefts are responsible for the asymmetric full-wave rectification and the response polarity in the phase-frequency characteristics. It is the asymmetric full-wave rectification and consequent receptor-potential waveforms that produce the 2 spikes/stimulus cycle plateaus in the characteristics relating firing rate to stimulus intensity described in the preceding paper (5). An additional model, based on the recovery of spike threshold, suggests how the plateaus in the firing rate-intensity characteristics (5) are produced. For the frequency domain, three filters in cascade can account for the frequency characteristic obtained with a constant firing rate criterion (see Ref. 5).(ABSTRACT TRUNCATED AT 400 WORDS)

Intensity and frequency characteristics of pacinian corpuscles. III. Effects of tetrodotoxin on transduction process

1984 ◽  
Vol 51 (4) ◽  
pp. 831-839 ◽  
Author(s):  
S. J. Bolanowski
Keyword(s):  
Vibration Frequency ◽  
Action Potentials ◽  
Time Course ◽  
Receptor Potential ◽  
Frequency Characteristics ◽  
Cycle Period ◽  
Driving Frequency ◽  
Pacinian Corpuscles ◽  
Percentage Decrease ◽  
High Stimulus

This is the third in a series of three papers dealing with intensity and frequency characteristics obtained on pacinian corpuscles isolated from the cat mesentery (8, 9). The experimental results show that tetrodotoxin (TTX) affects not only regenerative action potentials but also the measured receptor (generator) potentials. Extracellularly recorded receptor and action potentials were simultaneously recorded in response to sinusoidal displacement stimuli. Receptor potentials measured in this manner responded with a time course similar to the driving frequency. Since the duration of the action potentials is long relative to the cycle period at high stimulus frequencies, the underlying receptor potentials can become obscured. To prevent this, TTX was applied through superfusion at a concentration of 6.0 microM. After about 30 min, the neural spikes were fully eliminated but the receptor potentials were also decreased in amplitude. Intensity characteristics relating receptor-potential amplitudes to probe displacement amplitudes showed that the percentage decrease in amplitude due to the application of TTX was constant regardless of stimulus intensity. Frequency characteristics relating probe displacement amplitudes to vibration frequency for a constant-response criterion showed an increase in the displacement amplitude required for the criterion response, across frequency, when TTX was applied. On average, the increase was a power function of vibration frequency.(ABSTRACT TRUNCATED AT 250 WORDS)

Intensity and frequency characteristics of pacinian corpuscles. I. Action potentials

1984 ◽  
Vol 51 (4) ◽  
pp. 793-811 ◽  
Author(s):  
S. J. Bolanowski ◽  
J. J. Zwislocki
Keyword(s):  
Firing Rate ◽  
Phase Locking ◽  
Stimulus Frequency ◽  
Receptor Potential ◽  
Frequency Characteristics ◽  
Maximum Sensitivity ◽  
Response Criterion ◽  
Neural Firing ◽  
Pacinian Corpuscles ◽  
Amplitude Frequency Characteristic

The mechanisms by which pacinian corpuscles, isolated from cat mesentery, transduce mechanical stimuli have been measured for directly applied sinusoidal deformations. Stimulus-response relationships were measured as follows: intensity characteristics, which relate the receptor-potential magnitude or the neural firing rate to stimulus intensity; amplitude-frequency characteristics, which relate the stimulus amplitude to stimulus frequency for a given response criterion; and phase-frequency characteristics, which relate the phase angle between the stimulus and the receptor response to stimulus frequency. This report, the first in a series of three, deals with the characteristics reflected in the neural firing rate. The two reports that follow deal with the receptor potential, which, if of sufficient amplitude, generates the propagated action potential. In the majority of the pacinian corpuscles investigated, the intensity characteristics for neural firing rates were steep at low stimulus intensities and plateaued at submultiples and multiples of the stimulus frequency as stimulus intensity was increased. Poststimulus time and interval histograms reveal that the plateaus occur as a result of phase locking to the stimulus. The submultiples and multiples of stimulus frequency at which phase locking was found and the length of the plateaus depended on stimulus frequency. These plateaus were eliminated with the use of narrow-band noise stimuli. The amplitude-frequency characteristics obtained with either a criterion of constant firing rate or that of a constant number of neural spikes per stimulus cycle were U-shaped functions. Their positions along both the intensity and frequency continua are affected by response criterion. For example, the mean (n = 19) amplitude-frequency characteristic generated with a constant firing rate criterion of 1 spike/s has a maximum sensitivity of about -37.0 dB re 1-micron peak and a best frequency (BF, stimulus frequency where maximum sensitivity occurs) of 465 Hz. The bandwidth, measured by Q3 dB, is 1.02. Alternatively, the average (n = 16) amplitude-frequency characteristic obtained with a response criterion of 1 spike per stimulus cycle has a maximum sensitivity of about -25.0 dB re 1-micron peak, a BF of 270 Hz and Q3 dB value of 1.16. Spontaneous activity (SPA; activity in the absence of controlled stimuli) was found in 13.6% of the pacinian corpuscles. Intensity characteristics and frequency characteristics of these corpuscles show features similar to those of corpuscles without spontaneous activity except that the intensity characteristics asymptote to SPA levels at low stimulus intensities.(ABSTRACT TRUNCATED AT 400 WORDS)

Calculation about the Fundamental Wave Amplitude of the Current in the Distribution Line on Wavelet Analysis

2011 ◽  
Vol 308-310 ◽  
pp. 1357-1360
Author(s):  
Chang Chun Chi ◽  
Jian Wei Chen ◽  
Yi Wu
Keyword(s):  
Wavelet Analysis ◽  
Frequency Characteristic ◽  
Wave Amplitude ◽  
Engineering Practice ◽  
Fundamental Wave ◽  
Time Frequency ◽  
Full Wave ◽  
Distribution Line ◽  
Complex Wavelet ◽  
Dc Component

Wavelet analysis, as a new kind of time-frequency representation technique, has made great progress recently and been applied widely in different engineering practice. To solve the problem of full-wave Fourier algorithm which is disable to filter decaying DC component and has worse frequency characteristic, it is presented an improved algorithm depending on the combination of subtraction filter and full-wave Morlet complex wavelet, to get out the fundamental wave amplitude of the current in the distribution line, by studying each parameter’s influence on the performances of Morlet complex wavelet algorithm. It can filter decaying DC component efficiently and has better frequency characteristic.

Effect of External Calcium Concentration on the Intensity Dependence of Light-Induced Membrane Current and Voltage Signals in Two Defined States of Adaptation in the Photo-Receptor of Limulus

1986 ◽  
Vol 41 (11-12) ◽  
pp. 1092-1110 ◽  
Author(s):  
H. Stieve ◽  
H. Gaube ◽  
J. Klomfaß
Keyword(s):  
Stimulus Intensity ◽  
Time Course ◽  
Calcium Concentration ◽  
Light Adaptation ◽  
Receptor Potential ◽  
Membrane Current ◽  
Current Response ◽  
Current Signal ◽  
Intensity Dependence ◽  
Attenuation Function

Abstract The intensity dependence of the response of the Limulus ventral nerve photoreceptor to light flashes was determined in alternating measurements for the membrane current signal (receptor current) under voltage clamp conditions and the membrane voltage signal (receptor potential). Responses were obtained at two reproducible states of adaptation, while the photoreceptor was superfused by physiological saline (10 mmol/l Ca2+), or by salines with either lowered (250 μmol/l) or raised (40 mmol/l) calcium concentration. For the dark-adapted state of the photoreceptor the double logarithmic plot of the response current-time integral F (or the current amplitude) vs. flash intensity rises in a steep, supralinear section (slope 2-4) to a curve knee towards a less steep, sublinear section (slope 0.2-0.6), but does not reach saturation in the intensity range tested. Light adaptation shifts the response size vs. intensity curve towards higher light intensities. This sensitivity shift is enlarged in raised, and almost abolished in low external [Ca2+]. The changes of response latency and time-to-peak with stimulus intensity or adaptation are almost identical for receptor current and receptor potential. The decrease-time of the receptor current response, however, depends much less on the stimulus intensity or the state of adaptation than that of the receptor potential. The relative changes in the time course of the receptor current caused by light adaptation are not much influenced by variation of the [Ca2+]ex. Interpretation: The macroscopic receptor current signal consists of a volley of overlapping bumps; the size of these bumps is scaled by a calcium-dependent attenuation function which increases with delay time. This gradual growing attenuation a(t) acts as automatic gain control and may be responsible for the sublinear slope of the intensity dependence of the size of the receptor current. The supralinear slope of this dependence at lower stimulus intensities is probably caused by cooperative effects. Changes in the time course of the macroscopic receptor current due to light adaptation or varied calcium concentration are based on changes in the latency distribution of the underlying bump volley, and the size of the attenuation function.

The Analysis of Rogowski Coil Transfer Characteristics in the Composite Frequency Environment

2013 ◽  
Vol 816-817 ◽  
pp. 450-453
Author(s):  
Hai Bao ◽  
Xin Yuan Guo ◽  
Ling Wang ◽  
Gang Liu
Keyword(s):  
Frequency Characteristic ◽  
Rogowski Coil ◽  
Frequency Characteristics ◽  
Reference Standard ◽  
Frequency Signal ◽  
Transfer Ratio ◽  
Transfer Characteristics ◽  
Simulation Results ◽  
Secondary Side

This article uses the method of frequency characteristic to analysis transfer characteristics of Rogowski coil. In the case of the composite frequency signal, Rogowski coil transfer ratio is the function of frequency, that is the transfer ratio varies with the frequency, which makes the signal of the secondary side not restore to the primary side. The simulation results prove the conclusion. In view of the situation, this paper presents an ideal transfer ratio, which provides the reference standard for correcting the frequency characteristics of the Rogowski coil integrating circuit.

scholarly journals The ionic mechanism of gamma resonance in rat striatal fast-spiking neurons

2011 ◽  
Vol 106 (6) ◽  
pp. 2936-2949 ◽  
Author(s):  
Giuseppe Sciamanna ◽  
Charles J. Wilson
Keyword(s):  
Firing Rate ◽  
Firing Pattern ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Repetitive Firing ◽  
Spike Threshold ◽  
Gamma Frequency ◽  
Subthreshold Oscillations ◽  
Fast Spiking

Striatal fast-spiking (FS) cells in slices fire in the gamma frequency range and in vivo are often phase-locked to gamma oscillations in the field potential. We studied the firing patterns of these cells in slices from rats ages 16–23 days to determine the mechanism of their gamma resonance. The resonance of striatal FS cells was manifested as a minimum frequency for repetitive firing. At rheobase, cells fired a doublet of action potentials or doublets separated by pauses, with an instantaneous firing rate averaging 44 spikes/s. The minimum rate for sustained firing was also responsible for the stuttering firing pattern. Firing rate adapted during each episode of firing, and bursts were terminated when firing was reduced to the minimum sustainable rate. Resonance and stuttering continued after blockade of Kv3 current using tetraethylammonium (0.1–1 mM). Both gamma resonance and stuttering were strongly dependent on Kv1 current. Blockade of Kv1 channels with dendrotoxin-I (100 nM) completely abolished the stuttering firing pattern, greatly lowered the minimum firing rate, abolished gamma-band subthreshold oscillations, and slowed spike frequency adaptation. The loss of resonance could be accounted for by a reduction in potassium current near spike threshold and the emergence of a fixed spike threshold. Inactivation of the Kv1 channel combined with the minimum firing rate could account for the stuttering firing pattern. The resonant properties conferred by this channel were shown to be adequate to account for their phase-locking to gamma-frequency inputs as seen in vivo.

Research on Seismic Performance of Large Span Integral Suspended Ceiling Structure in Decoration Engineering

2013 ◽  
Vol 639-640 ◽  
pp. 901-905
Author(s):  
You Jun Zhang ◽  
Zhong Ping Tang ◽  
De Lai Liu
Keyword(s):  
Seismic Performance ◽  
Vibration Frequency ◽  
Natural Vibration ◽  
Vibration Mode ◽  
Frequency Characteristics ◽  
Natural Vibration Frequency ◽  
Ansys Software ◽  
Large Span ◽  
Constructional Design

The natural vibration frequency, characteristics of vibration mode and deformation of large span integral ceiling structure in a hotel under earthquake were studied using the ANSYS Software, then some useful suggestions on hoisting position, pull rod and other factors were put forward for seismic constructional design of large span integral suspended ceiling structures.

Proteinase-Activated Receptor-4 (PAR4) Activation Leads to Sensitization of Rat Joint Primary Afferents Via a Bradykinin B2 Receptor-Dependent Mechanism

2010 ◽  
Vol 103 (1) ◽  
pp. 155-163 ◽  
Author(s):  
Fiona A. Russell ◽  
Victoria E. Veldhoen ◽  
Dmitri Tchitchkan ◽  
Jason J. McDougall
Keyword(s):  
Firing Rate ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Primary Afferents ◽  
Knee Joints ◽  
Transient Receptor Potential Vanilloid ◽  
Mechanical Stimuli ◽  
Male Wistar Rats ◽  
Normal Rat

The G-protein-linked receptor, proteinase-activated receptor-4 (PAR4) is activated by proteinases released into the joint during inflammation. It is unclear whether PAR4 has a pro- or anti-nociceptive effect and whether it directly affects nerve activity. In this study, we examined the expression of PAR4 in joints and dorsal root ganglion (DRG) neurons and whether activation of PAR4 has an effect on nociception in normal rat knee joints. Electrophysiological recordings were made from joint primary afferents in male Wistar rats during both nonnoxious and noxious rotations of the knee. Afferent firing rate was recorded for 15 min post close intra-arterial injection of 10−9–10−5 mol of the PAR4 activating peptide, AYPGKF-NH2, or the inactive peptide, YAPGKF-NH2 (100 μl bolus). Rats were either naive or pretreated with the selective PAR4 antagonist, pepducin P4pal-10, the transient receptor potential vanilloid-1 (TRPV1) antagonist, SB366791, or the bradykinin B2 receptor antagonist, HOE140. Immunofluorescence experiments showed extensive PAR4 expression in the knee joint and in sensory neurons projecting from the joint. AYPGKF-NH2 significantly increased joint afferent firing during nonnoxious and noxious rotation of the knee. The inactive control peptide, YAPGKF-NH2 was without effect. Systemic pretreatment with the PAR4 antagonist, pepducin P4pal-10, inhibited the AYPGKF-NH2-induced increase in firing rate. Pretreatment with HOE140, but not SB366791, also blocked this increase in firing rate. These data reveal that in normal rat knee joints, PAR4 activation increases joint primary afferent activity in response to mechanical stimuli. This PAR4-induced sensitization is TRPV1-independent but involves B2 receptor activation, suggesting a role for kinins in this process.

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