scholarly journals Functional organisation of anterior thoracic stretch receptors in the deep-sea isopod Bathynomus doederleini: behavioural, morphological and physiological studies

2001 ◽  
Vol 204 (20) ◽  
pp. 3411-3423 ◽  
Author(s):  
Masazumi Iwasaki ◽  
Ayako Ohata ◽  
Yoshinori Okada ◽  
Hideo Sekiguchi ◽  
Akiyoshi Niida
Keyword(s):  
Deep Sea ◽  
Dynamic Range ◽  
Adaptive Behaviour ◽  
Cell Type ◽  
Segmental Mobility ◽  
Tonic Response ◽  
Single Receptor ◽  
Stretch Receptors ◽  
Receptor Organ ◽  
Receptor Muscle

SUMMARY The relationship between segmental mobility and the organisation of thoracic stretch receptors was examined in the deep-sea isopod Bathynomus doederleini, which shows a developed adaptive behaviour during digging. The movements of segments during digging were analysed from video recordings, which showed that a large excursion occurred in the anterior thoracic segments. Dye-fills of axons revealed four types of thoracic stretch receptor (TSR): an N-cell type (TSR-1), a differentiated N-cell type (TSR-2), a muscle receptor organ (MRO)-type with a long, single receptor muscle (TSR-3) and an MRO-type with a short, single receptor muscle (TSR-4 to TSR-7). Physiologically, TSR-1 and TSR-2 are tonic-type stretch receptors. TSR-3 to TSR-7 show two kinds of stretch-activated responses, a tonic response and a phasico-tonic response in which responses are maintained as long as the stretch stimulus is delivered. Both TSR-2, with a long muscle strand, and TSR-3, with a single, long receptor muscle, have a wide dynamic range in their stretch-activated response. In addition, TSR-2 is controlled by an intersegmental inhibitory reflex from TSR-3. These results suggest that, although TSR-1 has no receptor muscle and TSR-2 has a less-differentiated receptor-like muscle, they are fully functional position detectors of segmental movements, as are the MRO-type receptors TSR-3 to TSR-7.

Zeitlich abklingende Vorgänge in der Wirkungskette zwischen Reiz und Erregung (Versuche an abdominalen Streckreceptoren dekapoder Krebse).

1961 ◽  
Vol 16 (7) ◽  
pp. 464-469 ◽  
Author(s):  
Lotte Wendler ◽  
D. Burkhardt
Keyword(s):  
Steady State ◽  
Nerve Cell ◽  
Sensory Nerve ◽  
State Level ◽  
Constant Load ◽  
Steady State Level ◽  
Stretch Receptors ◽  
Two Factors ◽  
Receptor Organ ◽  
Receptor Muscle

The crayfish stretch receptors show a characteristic pattern of excitation: after a sudden stretch the sensory discharge increases rapidly and then decays to a new steady state level. This decrease, commonly called adaptation, is referred to in the present work as “decay of excitation”. Stimulating the receptor organ with a constant load or a constant lengthening reveals that there are at least two factors responsible for the decay of excitation, i. e. the visco-elastic properties of the receptor muscle and the accomodation of the sensory nerve cell.

scholarly journals THE MODULATORY EFFECTS OF SEROTONIN, NEUROPEPTIDE F1 AND PROCTOLIN ON THE RECEPTOR MUSCLES OF THE LOBSTER ABDOMINAL STRETCH RECEPTOR AND THEIR EXOSKELETAL MUSCLE HOMOLOGUES

1993 ◽  
Vol 174 (1) ◽  
pp. 363-374
Author(s):  
V. M. Pasztor ◽  
L. B. Golas
Keyword(s):  
Muscle Fibres ◽  
Sensory Afferents ◽  
Tension Development ◽  
Sensory Neurones ◽  
Multiple Loci ◽  
Receptor Organ ◽  
Two Measures ◽  
Low Incidence ◽  
Passive Stretch ◽  
Receptor Muscle

The muscle receptor organ (MRO) of the lobster is a complex proprioceptive system lying in parallel with the axial extensor musculature. Two peripherally located sensory neurones extend stretch-sensitive dendrites into individual receptor muscle strands one tonic (RM1) and one phasic (RM2). Previous studies have shown that the sensitivity of the sensory neurones to passive stretch could be enhanced by serotonin and proctolin. Here we show that the receptor muscles and their exoskeletal muscle homologues are also responsive to serotonin, proctolin and, in addition, to neuropeptide F1 (TNRNFLRF-NH2). Two measures of motor performance were enhanced by all three neurohormones: EJP amplitude and nerve-evoked tension development. Serotonin was the most effective modulator of both tonic and phasic muscles. F1 had powerful effects on the phasic extensor muscle. A low incidence of tonic muscle fibres with synapses responding to the neurohormones suggests that there are distinct populations of synapses: those sensitive to specific modulators and others that are insensitive. These findings, taken together with the enhancing effects of modulation on the primary sensory afferents, suggest that circulating neurohormones may act at multiple loci in the MRO system in a concerted and hormone-specific manner to alter the flow of proprioceptive feedback.

Reflexes Mediated by Non-Impulsive Afferent Neurones of Thoracic-Coxal Muscle Receptor Organs in the Crab, Carcinus Maenas: I. Receptor Potentials and Promotor Motoneurone Responses

1980 ◽  
Vol 86 (1) ◽  
pp. 275-303
Author(s):  
A. J. CANNONE ◽  
B. M. H. BUSH
Keyword(s):  
Carcinus Maenas ◽  
Receptor Potential ◽  
Reflex Response ◽  
Shore Crab ◽  
Sensory Fibre ◽  
Muscle Receptor ◽  
Receptor Organ ◽  
Length Changes ◽  
Receptor Muscle

Address for reprints. 1. A preparation of the thoracic-coxal muscle receptor organ of the posterior leg of the shore crab, in which central synaptic efficacy of the sensori-motor reflex pathways is maintained for long periods, is described. 2. The reflex response to receptor muscle stretch commonly involves three promotor motoneurones, designated Pm1-3 in order of their recruitment. 3. Motoneurone Pm1, and less frequently Pm2 and Pm3, may be tonically active during maintained receptor length changes within the in situ length range of the receptor muscle. 4. The following observations suggest that the T rather than the S sensory fibre provides the afferent drive onto reflexly activated promotor motoneurones: selective section of the S or T sensory fibres; frequency ‘envelopes’ of individual motoneurone responses to trapezoid stretch stimuli, including features such as adaptation and velocity sensitivity of the reflex response; and the ‘hysteresis’ in the response to increasing followed by decreasing receptor length changes, with or without superimposed trapezoid stretch stimuli. 5. The initial reflex response to ramp stretch can be directly related to the complex ‘initial component’ of the T fibre receptor potential waveform. This comprises a variable spiky alpha (α) component, followed by a longer duration, more predictable beta (β) component, which depends upon stimulus parameters such as stretch velocity and the length and tension of the receptor muscle at the onset of stretch. 6. In the de-efferented receptor muscle, changes in compliance or ‘tonus’ resulting from receptor manipulation have a marked effect on the sensory, and hence reflex, response to stretch. As this would have profound implications for the functioning of this muscle receptor organ in vivo, a role for the receptor motor innervation in counteracting any such response variability seems likely.

scholarly journals Stretch Receptor Organs in Squilla Mantis Latr. (Crustacea: Stomatopoda)

1964 ◽  
Vol 41 (4) ◽  
pp. 793-804 ◽  
Author(s):  
R. L. C. PILGRIM
Keyword(s):  
Single Cell ◽  
Stretch Receptor ◽  
Thoracic Segment ◽  
The Other ◽  
Sensory Cells ◽  
The Third ◽  
Amino Butyric Acid ◽  
Single Receptor ◽  
Abdominal Organs ◽  
Receptor Muscle

1. Structures which have been described as muscle receptor organs were found to respond to experimentally applied stretch. The presence of both slowly-adapting and fast-adapting receptors was determined in those organs where two sensory cells and two receptor muscles have been described, i.e. in the abdomen and posterior four thoracic segments. 2. In the fourth thoracic segment, with two cells on a single receptor muscle, one organ is slowly-adapting and the other fast-adapting, with properties not distinguishable from those where separate receptor muscles are present. 3. In the third thoracic segment, with a single cell and receptor muscle, the organ is slowly-adapting. 4. In the second thoracic segment a slowly-adapting cell was discovered. It is without a receptor muscle or accessory innervation and resembles an N-cell of the Decapoda. 5. The reactions of the abdominal organs to acetylcholine and to γ-amino butyric acid are qualitatively similar to those in Decapoda. 6. The series of stretch-sensitive organs in Squilla and in Decapoda are compared.

scholarly journals Neural Mechanism of Hearing in Insects

1960 ◽  
Vol 37 (2) ◽  
pp. 279-290
Author(s):  
YASUJI KATSUKI ◽  
NOBUO SUGA
Keyword(s):  
Stimulus Frequency ◽  
Neural Mechanism ◽  
Dominant Frequency ◽  
Ultrasonic Waves ◽  
Frequency Range ◽  
Single Receptor ◽  
Receptor Organ ◽  
Species Specific ◽  
Different Response ◽  
Very High

1. The frequency response ranges of the tympanal and cercal nerve were measured in ten species belonging to four families, Cicadidae, Acridiidae, Tettigoniidae and Gryllidae. The tympanal organs of Acridiidae and Tettigoniidae responded to ultrasonic waves and the most effective frequency was very high (> 10 kc./s.), while the response ranges of the other two families, Cicadidae and Gryllidae, were within that of man. The response ranges of the cercal nerves (lower) and tympanal nerves (higher) were partly overlapping. 2. Stridulation consisted of pulsatory sounds and had species-specific rhythms, to which the tympanal nerves responded with synchronous discharge. 3. The dominant frequency range involved in stridulation agreed well with the frequency range to which the tympanal organ of the same insect was most sensitive. 4. The threshold of the tympanal nerve varied with different directions of incident sound, especially for ultrasonic waves, indicating the possibility of directional sense. 5. Tympanal neurons of Gampsocleis buergeri were referable to two types having different response ranges. 6. The curves relating number of spikes per second to intensity of stimulus were sigmoid and almost parallel for different frequencies. 7. In Discussion it is pointed out that although no single receptor organ is able to discriminate stimulus frequency, an insect which has different sound receptors on various parts of its body may have some power of discrimination.

Chemosensitivity of crayfish slowly adapting stretch receptors to nicotine

1985 ◽  
Vol 59 (5) ◽  
pp. 1597-1600 ◽  
Author(s):  
R. F. Taylor ◽  
D. T. Frazier
Keyword(s):  
Chemical Interaction ◽  
Muscle Tension ◽  
Stretch Receptor ◽  
Receptor Activity ◽  
Chemical Effect ◽  
Sensory Receptor ◽  
Crayfish Muscle ◽  
Stretch Receptors ◽  
Receptor Organ ◽  
Nerve Recordings

It has recently been demonstrated that slowly adapting stretch receptors (SASRs) in the airways of the dog respond directly to nicotine (Federation Proc. 43: 318, 1984). The purpose of the present experiment was to investigate this chemical effect on an isolated stretch receptor. The crayfish muscle receptor organ was chosen, since crayfish muscle is reported to be insensitive to nicotine or acetylcholine and therefore permits the testing of any direct chemical effect of nicotine on the muscle stretch receptors. The tail was removed and pinned out in a tissue bath, and a stretch receptor organ was surgically isolated. Single-unit SASR extracellular nerve recordings were made while simultaneously measuring tension in the tail. Drugs were prepared in Van Harreveld's solution and administered into the bath kept at 18 degrees C. When resting muscle tension was essentially reduced to zero by cutting both ends of the receptor organ muscle, nicotine (0.07 microM) added to the bath increased receptor activity fourfold. This response was abolished by treatment with hexamethonium (690 microM). In a second group of animals in which the muscle was left intact, nicotine was shown to significantly increase receptor sensitivity to step changes in muscle tension. Once again hexamethonium blocked the response to nicotine. These results demonstrate that the sensitivity of mechanoreceptor can be altered by chemical interaction with nicotinic receptors, which dramatically alter sensory receptor activity.

Some Effects of Receptor Muscle Contraction on the Responses of Slowly Adapting Abdominal Stretch Receptors of the Crayfish

1967 ◽  
Vol 46 (3) ◽  
pp. 445-458
Author(s):  
M. C. BROWN
Keyword(s):  
Motor Nerve ◽  
Maximal Response ◽  
Phasic Response ◽  
Constant Length ◽  
Constant Rate ◽  
Stretch Receptors ◽  
Excitatory Action ◽  
Final Length ◽  
Frequency Of Stimulation ◽  
Receptor Muscle

1. Stimulation of the motor fibres innervating the slowly adapting abdominal stretch receptors of the crayfish was carried out under the following circumstances: 2. With the receptors at a constant length the frequency of stimulation was varied. A maximal response from the receptors, which averaged about 50 impulses/sec, was obtained with stimulation rates of 50-80/sec. But low rates of stimulation (e.g. 10/sec.) had a powerful excitatory action, often 70% of maximal. 3. With the receptors stretched different amounts the motor fibres were stimulated at a constant rate. The increase in the receptor discharge caused by the contraction was the same over the range of lengths studied. 4. The receptors were stretched at a series of constant velocities (0.05-10 mm./sec.) to the same final length with and without motor-nerve stimulation. The contraction increased the frequency rise during the dynamic phase of stretch and increased the amount by which the frequency decayed at the end of the ramp. 5. The phasic response of the de-efferented receptor has previously been described by the following transfer function Fs=aΓ (1-k)sk, where a and k are constants. To a first approximation the effect of receptor contraction on this phasic response was to increase the value of the constant a, but to leave k unaffected.

scholarly journals Total mRNA Quantification in Single Cells: Sarcoma Cell Heterogeneity

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 759 ◽  
Author(s):  
Emma Jonasson ◽  
Lisa Andersson ◽  
Soheila Dolatabadi ◽  
Salim Ghannoum ◽  
Pierre Åman ◽  
...  
Keyword(s):  
Single Cell ◽  
Dynamic Range ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Human Fibroblasts ◽  
Mrna Levels ◽  
Cell Analysis ◽  
Cell Heterogeneity ◽  
Cell Type ◽  
Sarcoma Cell

Single-cell analysis enables detailed molecular characterization of cells in relation to cell type, genotype, cell state, temporal variations, and microenvironment. These studies often include the analysis of individual genes and networks of genes. The total amount of RNA also varies between cells due to important factors, such as cell type, cell size, and cell cycle state. However, there is a lack of simple and sensitive methods to quantify the total amount of RNA, especially mRNA. Here, we developed a method to quantify total mRNA levels in single cells based on global reverse transcription followed by quantitative PCR. Standard curve analyses of diluted RNA and sorted cells showed a wide dynamic range, high reproducibility, and excellent sensitivity. Single-cell analysis of three sarcoma cell lines and human fibroblasts revealed cell type variations, a lognormal distribution of total mRNA levels, and up to an eight-fold difference in total mRNA levels among the cells. The approach can easily be combined with targeted or global gene expression profiling, providing new means to study cell heterogeneity at an individual gene level and at a global level. This method can be used to investigate the biological importance of variations in the total amount of mRNA in healthy as well as pathological conditions.

scholarly journals Revealing unidentified heterogeneity in different epithelial cancers using heterocellular subtype classification

2017 ◽  
Author(s):  
Pawan Poudel ◽  
Gift Nyamundanda ◽  
Chanthirika Ragulan ◽  
Rita T. Lawlor ◽  
Kakoli Das ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Immune Cell ◽  
Cell Types ◽  
Cell Type ◽  
Cancer Subtypes ◽  
Epithelial Cancers ◽  
Unique Approach ◽  
Cancer Types ◽  
Well Differentiated ◽  
Cellular Compartments

AbstractCancers are currently diagnosed, categorised, and treated based on their tissue of origin. However, how different cellular compartments of tissues (e.g., epithelial, immune and stem cells) are similar across cancer types is unknown. Here we used colorectal cancer subtypes and their signatures representing different colonic crypt cell types as surrogates to classify different epithelial cancers into five heterotypic cellular (heterocellular) subtypes. The stem-like and inflammatory heterocellular subtypes are ubiquitous across epithelial cancers so capture intrinsic, tissue-independent properties. Conversely, well-differentiated/specialized goblet-like/enterocyte heterocellular subtypes differ across cancer types due to their colorectum-specific genes. The transit-amplifying heterocellular subtype shows a dynamic range of cellular differentiation with shared common pathways (Wnt, FGFR) in certain cancer types. Importantly, this approach revealed previously unrecognised heterogeneity in pancreatic, breast, microsatellite-instability enriched and KRAS mutation-dependent cancers. Immune cell-type differences are common and useful for patient stratification for immunotherapy. This unique approach identifies cell type-dependent but tissue-independent heterogeneity in different cancers for precision medicine.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

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