Involvement of receptor potentials and action potentials in mechano-perception in plants

2001 ◽  
Vol 28 (7) ◽  
pp. 567 ◽  
Author(s):  
Teruo Shimmen
Keyword(s):  
Action Potentials ◽  
Higher Plants ◽  
Single Cells ◽  
Receptor Potential ◽  
Large Cell ◽  
Carnivorous Plants ◽  
Mechanical Stimuli ◽  
Electrophysiological Studies ◽  
Motor Cells ◽  
Plant Membranes

The rapid turgor movements of Mimosa pudica and some carnivorous plants have long stimulated the interest of botanists. In addition, it is becoming evident that slower responses of plants to mechanical stimuli, such as coiling of tendrils and thigmomorphogenesis, are common phenomena. Electrophysiological studies on mechano-perception have been carried out in M. pudica and carnivorous plants, and have established that the response to mechanical stimulation is composed of three steps: perception of the stimulus, transmission of the signal, and induction of movement in motor cells. The first step is due to the receptor potential, the second and third steps are mediated by the action potential. In this article, the mechanisms of responses to mechanical stimuli of these plants are considered. Since higher plants are composed of complex tissues, detailed analysis of electrical phenomena is rather difficult, and so the mechanism for generating the receptor potential had not yet been studied. Characean cells have proved to be more amenable to the study of the electrophysiology of plant membranes because of their large cell size and the ease by which single cells can be isolated. Recent progress in studies of the receptor potential in characean cells is also discussed.

scholarly journals Receptor Response in Venus's Fly-Trap

1965 ◽  
Vol 49 (1) ◽  
pp. 117-129 ◽  
Author(s):  
Stuart L. Jacobson
Keyword(s):  
Action Potential ◽  
Mechanical Stimulation ◽  
Action Potentials ◽  
Natural Extension ◽  
Receptor Potential ◽  
Mechanical Stimuli ◽  
Dionaea Muscipula ◽  
Receptor Response ◽  
Current Measuring ◽  
Stimulation Of

The insect-trapping movement of the plant Dionaea muscipula (Venus's fly-trap) is mediated by the stimulation of mechanosensory hairs located on the surface of the trap. It is known that stimulation of the hairs is followed by action potentials which are propagated over the surface of the trap. It has been reported that action potentials always precede trap closure. The occurrence of non-propagated receptor potentials is reported here. Receptor potentials always precede the action potentials. The receptor potential appears to couple the mechanical stimulation step to the action potential step of the preying sequence. Receptor potentials elicited by mechanical stimulation of a sensory hair were measured by using the hair as an integral part of the current-measuring path. The tip of the hair was cut off exposing the medullary tissue; this provided a natural extension of the measuring electrode into the receptor region at the base of the hair. A measuring pipette electrode was slipped over the cut tip of the hair. Positive and negative receptor potentials were measured. Evidence is presented which supports the hypothesis that the positive and negative receptor potentials originate from independent sources. An analysis is made of (a) the relation of the parameters of mechanical stimuli to the magnitude of the receptor potential, and (b) the relation of the receptor potentials to the action potential. The hypothesis that the positive receptor potential is the generator of the action potential is consistent with these data.

scholarly journals Sodium-Calcium Action Potential Associated with Contraction in the Heliozoan Actinocoryne Contractilis

1986 ◽  
Vol 122 (1) ◽  
pp. 177-192 ◽  
Author(s):  
COLETTE FEBVRE-CHEVALIER ◽  
ANDRÉ BILBAUT ◽  
QUENTIN BONE ◽  
JEAN FEBVRE
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Receptor Potential ◽  
Resting Membrane Potential ◽  
Mechanical Stimuli ◽  
Free Solution ◽  
Sodium Calcium ◽  
Rapid Action ◽  
A Minor ◽  
Calcium Action Potential

The electrophysiology of the contractile protozoan Actinocoryne contractilis was studied with conventional intracellular recording techniques. Resting membrane potential (−78 mV, s.d. = 8, N = 18) was dependent upon external K+. Rapid action potentials (overshoot up to 50 mV) were evoked either by mechanical stimulation or by current injection. Graded membrane depolarizations induced by graded mechanical stimuli correspond to receptor potentials. The receptor potential was mainly Na+-dependent; the action potential was also mainly Na+-dependent, but involved a minor Ca2+-dependence. The two components of the action potential could be separated in Ca2+-free solution containing EGTA (1 mmol l−1), in low-Na+ solutions or by the addition of Co2+. The repolarizing phase of the action potential was sensitive to TEA ions and to 4-aminopyridine (4-AP). Action potentials were followed in 10–20 ms by a rapid all-or-none contraction of the axopods and stalk. Contraction was blocked in Ca2+-free solution containing EGTA and by Co2+, which suggests a requirement of external Ca2+ for this event. Contraction was also abolished by 4-AP.

scholarly journals Stochastic Spatial Heterogeneity in Activities of H+-ATP-ases in Electrically Connected Plant Cells Decreases Threshold for Cooling-Induced Electrical Responses

2021 ◽  
Vol 22 (15) ◽  
pp. 8254
Author(s):  
Ekaterina Sukhova ◽  
Daria Ratnitsyna ◽  
Vladimir Sukhov
Keyword(s):  
Spatial Heterogeneity ◽  
Action Potentials ◽  
Higher Plants ◽  
Electrical Response ◽  
Plant Cells ◽  
Excitable Cells ◽  
Molecular Transporters ◽  
Positive Shift ◽  
Stochastic Heterogeneity ◽  
Electrical Responses

H+-ATP-ases, which support proton efflux through the plasma membrane, are key molecular transporters for electrogenesis in cells of higher plants. Initial activities of the transporters can influence the thresholds of generation of electrical responses induced by stressors and modify other parameters of these responses. Previously, it was theoretically shown that the stochastic heterogeneity of individual cell thresholds for electrical responses in a system of electrically connected neuronal cells can decrease the total threshold of the system (“diversity-induced resonance”, DIR). In the current work, we tested a hypothesis about decreasing the thresholds of generation of cooling-induced electrical responses in a system of electrically connected plant cells with increasing stochastic spatial heterogeny in the initial activities of H+-ATP-ases in these cells. A two-dimensional model of the system of electrically connected excitable cells (simple imitation of plant leaf), which was based on a model previously developed in our works, was used for the present investigation. Simulation showed that increasing dispersion in the distribution of initial activities of H+-ATP-ases between cells decreased the thresholds of generation of cooling-induced electrical responses. In addition, the increasing weakly influenced the amplitudes of electrical responses. Additional analysis showed two different mechanisms of the revealed effect. The increasing spatial heterogeneity in activities of H+-ATP-ases induced a weak positive shift of the membrane potential at rest. The shift decreased the threshold of electrical response generation. However, the decreased threshold induced by increasing the H+-ATP-ase activity heterogeneity was also observed after the elimination of the positive shift. The result showed that the “DIR-like” mechanism also participated in the revealed effect. Finally, we showed that the standard deviation of the membrane potentials before the induction of action potentials could be used for the estimation of thresholds of cooling-induced plant electrical responses. Thus, spatial heterogeneity in the initial activities of H+-ATP-ases can be a new regulatory mechanism influencing the generation of electrical responses in plants under actions of stressors.

scholarly journals Localized mechanical stimulation of single cells with engineered spatio-temporal profile

Lab on a Chip ◽  
2018 ◽  
Vol 18 (19) ◽  
pp. 2955-2965 ◽  
Author(s):  
M. Monticelli ◽  
D. S. Jokhun ◽  
D. Petti ◽  
G. V. Shivashankar ◽  
R. Bertacco
Keyword(s):  
Cell Culture ◽  
Mechanical Stimulation ◽  
Single Cells ◽  
Mechanical Stimuli ◽  
Temporal Profile ◽  
A Cell ◽  
Spatio Temporal ◽  
Stimulation Of

We introduce a new platform for mechanobiology based on active substrates, made of Fe-coated polymeric micropillars, capable to apply mechanical stimuli with tunable spatio-temporal profile on a cell culture.

Transient receptor potential vanilloid 4 mediates protease activated receptor 2-induced sensitization of colonic afferent nerves and visceral hyperalgesia

2008 ◽  
Vol 294 (5) ◽  
pp. G1288-G1298 ◽  
Author(s):  
Walter E. B. Sipe ◽  
Stuart M. Brierley ◽  
Christopher M. Martin ◽  
Benjamin D. Phillis ◽  
Francisco Bautista Cruz ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Action Potentials ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Mechanical Hyperalgesia ◽  
Transient Receptor Potential Vanilloid ◽  
Afferent Neurons ◽  
Nociceptive Neurons ◽  
Afferent Fibers ◽  
Transient Receptor

Protease-activated receptor (PAR2) is expressed by nociceptive neurons and activated during inflammation by proteases from mast cells, the intestinal lumen, and the circulation. Agonists of PAR2 cause hyperexcitability of intestinal sensory neurons and hyperalgesia to distensive stimuli by unknown mechanisms. We evaluated the role of the transient receptor potential vanilloid 4 (TRPV4) in PAR2-induced mechanical hyperalgesia of the mouse colon. Colonic sensory neurons, identified by retrograde tracing, expressed immunoreactive TRPV4, PAR2, and calcitonin gene-related peptide and are thus implicated in nociception. To assess nociception, visceromotor responses (VMR) to colorectal distension (CRD) were measured by electromyography of abdominal muscles. In TRPV4+/+ mice, intraluminal PAR2 activating peptide (PAR2-AP) exacerbated VMR to graded CRD from 6–24 h, indicative of mechanical hyperalgesia. PAR2-induced hyperalgesia was not observed in TRPV4−/− mice. PAR2-AP evoked discharge of action potentials from colonic afferent neurons in TRPV4+/+ mice, but not from TRPV4−/− mice. The TRPV4 agonists 5′,6′-epoxyeicosatrienoic acid and 4α-phorbol 12,13-didecanoate stimulated discharge of action potentials in colonic afferent fibers and enhanced current responses recorded from retrogradely labeled colonic dorsal root ganglia neurons, confirming expression of functional TRPV4. PAR2-AP enhanced these responses, indicating sensitization of TRPV4. Thus TRPV4 is expressed by primary spinal afferent neurons innervating the colon. Activation of PAR2 increases currents in these neurons, evokes discharge of action potentials from colonic afferent fibers, and induces mechanical hyperalgesia. These responses require the presence of functional TRPV4. Therefore, TRPV4 is required for PAR2-induced mechanical hyperalgesia and excitation of colonic afferent neurons.

scholarly journals Mammalian Transient Receptor Potential TRPA1 Channels: From Structure to Disease

2020 ◽  
Vol 100 (2) ◽  
pp. 725-803 ◽  
Author(s):  
Karel Talavera ◽  
Justyna B. Startek ◽  
Julio Alvarez-Collazo ◽  
Brett Boonen ◽  
Yeranddy A. Alpizar ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Current Knowledge ◽  
Receptor Potential ◽  
Cellular Damage ◽  
Mechanical Stimuli ◽  
Amino Acid Residues ◽  
Nonselective Cation Channels ◽  
Organ Systems ◽  
Complex Regulation ◽  
Transient Receptor

The transient receptor potential ankyrin (TRPA) channels are Ca2+-permeable nonselective cation channels remarkably conserved through the animal kingdom. Mammals have only one member, TRPA1, which is widely expressed in sensory neurons and in non-neuronal cells (such as epithelial cells and hair cells). TRPA1 owes its name to the presence of 14 ankyrin repeats located in the NH2 terminus of the channel, an unusual structural feature that may be relevant to its interactions with intracellular components. TRPA1 is primarily involved in the detection of an extremely wide variety of exogenous stimuli that may produce cellular damage. This includes a plethora of electrophilic compounds that interact with nucleophilic amino acid residues in the channel and many other chemically unrelated compounds whose only common feature seems to be their ability to partition in the plasma membrane. TRPA1 has been reported to be activated by cold, heat, and mechanical stimuli, and its function is modulated by multiple factors, including Ca2+, trace metals, pH, and reactive oxygen, nitrogen, and carbonyl species. TRPA1 is involved in acute and chronic pain as well as inflammation, plays key roles in the pathophysiology of nearly all organ systems, and is an attractive target for the treatment of related diseases. Here we review the current knowledge about the mammalian TRPA1 channel, linking its unique structure, widely tuned sensory properties, and complex regulation to its roles in multiple pathophysiological conditions.

scholarly journals Electrophysiology of an Insect Heart

1963 ◽  
Vol 46 (4) ◽  
pp. 803-821 ◽  
Author(s):  
Frances V. McCann
Keyword(s):  
Action Potentials ◽  
Single Cells ◽  
Cardiac Pacemaker ◽  
Concentration Gradients ◽  
Virtual Absence ◽  
A Value ◽  
Structural Differences ◽  
Intracellular Microelectrodes ◽  
Extracellular Sodium

Bioelectric activity in single cells of the moth myocardium has been measured in situ with intracellular microelectrodes with particular reference to the bizarre ionic medium which bathes the tissues. Resting potentials averaged 47 mv, inside negative with respect to outside, despite a value of 11 mv calculated on the basis of transmembrane potassium concentration gradients. Action potentials overshoot as much as 12 mv in the virtual absence of extracellular sodium. Two "types" of action potentials have been recorded; one that resembles vertebrate atrial action potentials is found in the cephalic region of the tubular heart, and the other, similar in contour to vertebrate ventricular action potentials, is found in the areas posterior to the first abdominal segment. Histological sections indicate no structural differences between the two areas. Typical cardiac pacemaker type potentials occur but are not topographically localized. The effects of the omission from the perfusion fluid of the four major cationic constituents, Na+, K+, Ca++ and Mg++, on resting and action potentials may be summarized as: no effect, hyperpolarization, prolonged repolarization, and depolarization, respectively.

scholarly journals Growth and Division of Single Cells of Higher Plants in Vitro

1960 ◽  
Vol 43 (4) ◽  
pp. 841-851 ◽  
Author(s):  
Ludwig Bergmann
Keyword(s):  
Nicotiana Tabacum ◽  
Higher Plants ◽  
Single Cells ◽  
Tissue Cultures ◽  
Phaseolus Vulgaris L ◽  
Isolated Cells ◽  
Nicotiana Tabacum L ◽  
Agar Layer ◽  
Petri Dishes

The cultivation of single cells of Nicotiana tabacum L. var. "Samsun" and Phaseolus vulgaris L. var. "Early Golden Cluster" on a thin agar layer in Petri dishes is described. Under these conditions about 20 per cent of the cells divided repeatedly and established tissue clones which could be isolated and maintained as growing tissue cultures. It was possible also to follow the successive divisions of isolated cells and to observe their behavior during cytogenesis under the microscope.

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