scholarly journals Mathematical Distinction in Action Potential between Primo-Vessels and Smooth Muscle

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Seong-Jin Cho ◽  
Sang-Hun Lee ◽  
Wenji Zhang ◽  
Sae-Bhom Lee ◽  
Kwang-Ho Choi ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Smooth Muscle ◽  
Action Potential ◽  
Mathematical Analysis ◽  
Action Potentials ◽  
Type I ◽  
Type Ii ◽  
Analysis Method

We studied the action potential of Primo-vessels in rats to determine the electrophysiological characteristics of these structures. We introduced a mathematical analysis method, a normalized Fourier transform that displays the sine and cosine components separately, to compare the action potentials of Primo-vessels with those for the smooth muscle. We found that Primo-vessels generated two types of action potential pulses that differed from those of smooth muscle: (1) Type I pulse had rapid depolarizing and repolarizing phases, and (2) Type II pulse had a rapid depolarizing phase and a gradually slowing repolarizing phase.

Isolated Giant Smooth Muscle Fibres in Beroe Ovata: Ionic Dependence of Action Potentials Reveals Two Distinct Types of Fibre

1988 ◽  
Vol 135 (1) ◽  
pp. 343-362 ◽  
Author(s):  
ANDRÉ BILBAUT ◽  
ROBERT W. MEECH ◽  
MARI-LUZ HERNANDEZ-NICAISE
Keyword(s):  
Smooth Muscle ◽  
Action Potential ◽  
Action Potentials ◽  
Marine Invertebrate ◽  
The Body ◽  
Fibre Types ◽  
Resting Membrane Potential ◽  
Muscle Fibres ◽  
Beroe Ovata ◽  
Radial Muscle

1. The ionic dependence of action potentials evoked in giant smooth muscle fibres isolated by enzymatic digestion from the body wall of the marine invertebrate Beroe ovata (Ctenophora) has been investigated using conventional electrophysiological techniques. 2. Differences were observed in the two fibre types studied. The resting membrane potential was −60 ± 1.35 mV (N = 25) in longitudinal muscle fibres and −66 ±1.37 mV (N=32) in radial fibres. Action potentials had a short plateau in longitudinal fibres but not in radial fibres. 3. The action potential overshoot of both fibre types was decreased in Ca2+-free artificial sea water (ASW). In Na+-deficient ASW, action potentials could not be generated in radial fibres and showed a reduced overshoot in longitudinal fibres. 4. Tetrodotoxin (10−5moll−5) added to ASW or Ca2+-free ASW did not affect the action potentials of either type of fibre. 5. Action potentials of both fibres were partially blocked by Co2+ (20–50 mmoll−1) or Cd2+ (l-2mmoll−1). Action potentials of longitudinal fibres in Na+-deficient ASW were abolished by Co2+ (20mmoll−1). In Ca2+-free ASW, the ction potential overshoots of both sets of fibres were restored following the addition of Sr2+ or Ba2+. In longitudinal fibres, Sr2+ increased the duration of the action potential plateau. In both longitudinal and radial muscle fibres, Ba2+ prolonged the action potential. 6. In longitudinal fibres exposed to tetraethylammonium chloride (TEAC1) or 4-aminopyridine (4AP), the action potential was slightly prolonged. In these fibres, TEA+ or 4AP added to Ca2+-free ASW induced only a long-lasting depolarizing plateau. In radial fibres, the action potential duration was slightly increased in the presence of TEA+; it was unaffected by 4AP. In Ca2+-free ASW, TEA+ and 4AP induced an oscillating membrane response which appeared to be dependent on the intensity of the injected current pulse. 7. It is concluded that (a) there are significant differences between the action potentials of longitudinal and radial muscle fibres but that both are dependent on Na+ and Ca2+, (b) in longitudinal fibres, a Ca2+-activated K+ conductance and a TEA+-sensitive voltage-activated K+ conductance contribute to the repolarizing phase of the action potential, the former being predominant, (c) in radial fibres, the repolarizing phase of action potentials probably involves different membrane K+ conductances among which is a TEA+-sensitive K+ conductance.

Cholinergic nerve-mediated excitation in the guinea pig choledochoduodenal junction activated by distension

1994 ◽  
Vol 267 (5) ◽  
pp. G938-G946 ◽  
Author(s):  
F. Vogalis ◽  
R. R. Bywater ◽  
G. S. Taylor
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Action Potential ◽  
Action Potentials ◽  
Discharge Rate ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Circular Muscle Layer ◽  
Circular Layer ◽  
Longitudinal Layer

The electrical basis of propulsive contractions in the guinea pig choledochoduodenal junction (CDJ), which are triggered by distension, was investigated using intracellular microelectrode recording techniques. The isolated CDJ was placed in a continuously perfused tissue chamber at 37 degrees C. Membrane potential was recorded from smooth muscle cells in either the ampulla or in the upper CDJ (upper junction) regions, which were immobilized by pinning. Distension of the upper junction (20-30 s) by increasing intraductal hydrostatic pressure (mean elevation: 2.0 +/- 0.3 kPa, n = 13) triggered "transient depolarizations" (TDs: < 5 mV in amplitude and 2-5 s in duration) and action potentials in the circular muscle layer of the ampulla. The frequency of TDs in the ampulla was increased from 2.2 +/- 0.2 to 15.9 +/- 2.2 min-1 (n = 13) during distension. Simultaneous impalements of cells in the longitudinal and circular muscle layers in the ampulla revealed that subthreshold TDs in the circular layer were associated with an increased rate of action potential discharge in the longitudinal layer. Atropine (Atr; 1.4 x 10(-6) M) and tetrodotoxin (TTX; 3.1 x 10(-6) M blocked the distension-evoked increase in TD frequency, without affecting the frequency of ongoing TDs. The sulfated octapeptide of cholecystokinin (1-5 x 10(-8) M) increased the amplitude of TDs recorded in the circular muscle layer of the ampulla and increased action potential discharge rate. In separate recordings, radial stretch of the ampulla region increased the rate of discharge of action potentials in the smooth muscle of the upper junction.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophysiological Characteristics of Classes of Neuron in the HVc of the Zebra Finch

1998 ◽  
Vol 80 (2) ◽  
pp. 914-923 ◽  
Author(s):  
Michinori Kubota ◽  
Ikuo Taniguchi
Keyword(s):  
Action Potential ◽  
Zebra Finch ◽  
Action Potential Duration ◽  
The Other ◽  
Time Dependent ◽  
Inward Rectification ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Type Iv

Kubota, Michinori and Ikuo Taniguchi. Electrophysiological characteristics of classes of neuron in the HVc of the zebra finch. J. Neurophysiol. 80: 914–923, 1998. Whole cell recordings were made from zebra finch HVc neurons in slice preparations. Four distinct classes of neuron were found on the basis of their electrophysiological properties. The morphological characteristics of some of these neurons were also examined by intracellular injection of Lucifer yellow. Type I neurons (21 of 65 cells) had longer time-to-peak of an afterhyperpolarization following an action potential than the other classes. They exhibited both fast and time-dependent inward rectification and an initial high-frequency firing followed by a slower constant firing. Type I neurons had large somata and thick dendrites with many spines. The axons of some of the neurons in this class projected in the direction of area X of the parolfactory lobe. Type II neurons (30 of 65 cells) had a more negative resting membrane potential than the other classes. They exhibited fast inward rectification. Type II neurons could be divided into two subclasses by the absence (IIa; 22 cells) and the presence (IIb; 8 cells) of a low-threshold transient depolarization. Type IIa neurons had relatively small somata and thin, spiny dendrites. The axons of some of the neurons in this class projected in the direction of the robust nucleus of the archistriatum (RA). Type IIb neurons had relatively large somata and thick dendrites with many spines. Type III neurons (6 of 65 cells) had a shorter action-potential duration than the other classes. They exhibited prominent time-dependent inward rectification and a regular tonic firing with little or no accommodation. Type III neurons had beaded, aspiny dendrites. Type IV neurons (8 of 65 cells) had a longer action-potential duration, a much larger input resistance, and longer membrane time constant than the other classes. Type IV neurons had small somata and thin, short, sparsely spiny dendrites. The axons of some of the neurons in this class projected in the direction of the RA. These classes of neuron may play distinct roles in song production and representation in the HVc.

Effect of sodium deficiency of the action potential of the smooth muscle of ureter

1964 ◽  
Vol 206 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Makoto Kobayashi ◽  
Hiroshi Irisawa
Keyword(s):  
Smooth Muscle ◽  
Action Potential ◽  
Action Potentials ◽  
Essential Role ◽  
Choline Chloride ◽  
Resting Potential ◽  
Sodium Deficiency ◽  
Repolarization Phase ◽  
Extracellular Sodium

Action potentials of the smooth muscle of cat ureter were studied by using ultramicroelectrodes. Among 193 penetrations, the resting potential averaged 45 mv and the amplitude of action potential 32 mv. In four instances a slight overshoot was recorded. Action potential consisted of a relatively rapid rising phase followed by a slow repolarization phase, and its duration was about 0.3 sec. Effects of sodium deficiency on action potential were studied by using three different sodium substitutes. Both the height and the rising rate of action potential decreased as the concentration of extracellular sodium was reduced, indicating that the action potential of ureter muscle can be explained on the basis of sodium theory. The duration of the action potential was prolonged when sucrose or choline chloride was used as a sodium substitute; on the other hand, it shortened when tris chloride was employed. The essential role of sodium ions in the development of the action potential in ureter muscle is discussed.

Rheo-Optical Study of Polymers by Using Time-Resolved Soft-Pulse Compression Attenuated Total Reflection Step-Scan Fourier Transform Infrared Spectroscopy

2009 ◽  
Vol 63 (11) ◽  
pp. 1204-1210 ◽  
Author(s):  
Yuji Nishikawa ◽  
Tatsuhiko Nakano ◽  
Isao Noda
Keyword(s):  
Fourier Transform ◽  
Pulse Compression ◽  
Dynamic Compression ◽  
Pulse Frequency ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Type I ◽  
Type Ii ◽  
Time Resolved ◽  
2D Ir

A time-resolved soft-pulse dynamic compression attenuated total reflection (ATR) step-scan Fourier transform rheo-optical system has been developed. This system was used to observe different viscoelastic properties of polyethyleneterephthalate (PET) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHx). Resonance features were observed in the dynamic compression ATR spectrum of PHBHx with 625 Hz soft-pulse frequency. In contrast, the dynamic compression ATR spectrum of PET showed no resonance features. The resonance feature of PHBHx was found at 1723 cm−1, which corresponds to the structural or morphological reorganization of a less ordered (Type II) crystalline form under compressive perturbation. The time-resolved evolution of infrared (IR) spectra was effectively analyzed by conventional generalized two-dimensional (2D) correlation analysis. The 2D-IR results indicate that the dynamic response of the well-ordered Type I crystalline state (1289 and 1261 cm−1) is faster than that of the Type II (1723, 1277, and 1228 cm−1). The present method shows promise for characterizing a wide variety of viscoelastic materials, including polymer alloys, blends, composites, and copolymers, and semicrystalline polymers.

Analog Transmission of Action Potential Fine Structure in Spiral Ganglion Axons

2021 ◽  
Author(s):  
Wenke Liu ◽  
Qing Liu ◽  
Robert A. Crozier ◽  
Robin L. Davis
Keyword(s):  
Fine Structure ◽  
Action Potential ◽  
Action Potentials ◽  
Spiral Ganglion ◽  
Type I ◽  
Sensory Afferents ◽  
Conduction Pathway ◽  
Highly Correlated ◽  
Voltage Gated Ion Channels ◽  
Ganglion Neurons

Action potential waveforms generated at the axon initial segment (AIS) are specialized between and within neuronal classes. But is the fine structure of each electrical event retained when transmitted along myelinated axons or is it rapidly and uniformly transmitted to be modified again at the axon terminal? To address this issue action potential axonal transmission was evaluated in a class of primary sensory afferents that possess numerous types of voltage-gated ion channels underlying a complex repertoire of endogenous firing patterns. In addition to their signature intrinsic electrophysiological heterogeneity, spiral ganglion neurons are uniquely designed. The bipolar, myelinated somata of type I neurons are located within the conduction pathway, requiring that action potentials generated at the first heminode must be conducted through their electrically excitable membrane. We utilized this unusual axonal-like morphology to serve as a window into action potential transmission to compare locally-evoked action potential profiles to those generated peripherally at their glutamatergic synaptic connections with hair cell receptors. These comparisons showed that the distinctively-shaped somatic action potentials were highly correlated with the nodally-generated, invading ones for each neuron. This result indicates that the fine structure of the action potential waveform is maintained axonally, thus supporting the concept that analog signaling is incorporated into each digitally-transmitted action potential in the specialized primary auditory afferents.

Local interneurons define functionally distinct regions within lobster olfactory glomeruli

1997 ◽  
Vol 200 (6) ◽  
pp. 989-1001
Author(s):  
M Wachowiak ◽  
C Diebel ◽  
B Ache
Keyword(s):  
Action Potentials ◽  
Spiny Lobster ◽  
Olfactory Nerve ◽  
Distinct Pattern ◽  
Type I ◽  
Type Ii ◽  
Type Iv ◽  
Olfactory Glomeruli ◽  
Cell Recording ◽  
Different Response

Whole-cell recording coupled with biocytin injection revealed four types of interneurons intrinsic to the olfactory lobe (OL) of the spiny lobster Panulirus argus. Each type of neuron had a distinct pattern of arborization within the three anatomically defined regions of OL glomeruli (cap, subcap and base). Type I interneurons innervated all three regions, while types II, III and IV branched only in the cap, subcap and base, respectively. Type I interneurons responded to electrical stimulation of the antennular (olfactory) nerve with a burst of 1&shy;20 action potentials and a 1&shy;10 s depolarization. Type II (cap) interneurons responded to the same input with a burst of 1&shy;3 action potentials followed by a shorter hyperpolarization. Type III (subcap) interneurons responded with a burst of 1&shy;6 action potentials followed by a delayed, 0.5&shy;4 s depolarization. Type IV (base) interneurons responded with a brief depolarization or a burst of 1&shy;3 action potentials followed by a 1 s hyperpolarization. The regionalized arborization and the different response properties of the type II, III and IV interneurons strongly imply that lobster olfactory glomeruli contain functionally distinct regions, a feature that should be useful in understanding the multiple synaptic pathways involved in processing olfactory input.

THE ELECTRICAL PROPERTIES OF THE SMOOTH MUSCLE CELL MEMBRANE

1958 ◽  
Vol 36 (9) ◽  
pp. 959-975 ◽  
Author(s):  
E. E. Daniel ◽  
H. Singh
Keyword(s):  
Smooth Muscle ◽  
Electrical Properties ◽  
Action Potential ◽  
Action Potentials ◽  
Maximum Rate ◽  
Sodium Current ◽  
Choline Chloride ◽  
Total Duration ◽  
Smooth Muscles ◽  
Sodium Concentration

In myometrium from pregnant cat, repetitive action potentials have been recorded during contraction. Using intracellular electrodes the depolarizations averaged 35 mv. Maximum rate of depolarization was 1–2 v/sec and the action potential duration varied from 250 milliseconds to much longer periods. Membrane reversal of up to 10 mv sometimes occurred. Total resistance decreased during depolarization and recovered during repolarization. Typical biphasic potentials were also recorded with extracellular electrodes. Their amplitude (peak to peak) varied from 0.3 to several millivolts and their duration (peak to peak) from 10–40 milliseconds. Reduction of external sodium concentration to as little as one-ninth normal (choline chloride or sucrose replacement) did not reduce the amplitudes of the resting or action potentials measured intracellularly or extracellularly, but decreased the action potential frequency. Membrane reversal still occurred with intracellular electrodes and the maximum rate of depolarization was unchanged. The rate of repolarization was increased so that the total duration of the action potential was 150 to 200 milliseconds. With extracellular electrodes, the peak to peak amplitudes were increased and the durations were unchanged. Further reduction of external sodium concentration to less than 15–20 meq/liter caused a contraction without further change in action potential configuration. Gradual relaxation and slowing of the repetition rate of action potentials occurred and resulted eventually in complete mechanical and electrical inactivity.Rabbit taenia coli were also studied and their electrical properties contrasted to those of cat myometrium. The conclusions were reached that: (1) the available evidence opposes the hypotheses that an inward sodium current accounts for depolarization in smooth muscle and (2) smooth muscles differed in their electrical properties and mechanisms of ion distribution not only from striate muscles but also from one another.

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