scholarly journals SPECIFIC NERVE IMPULSES FROM GUSTATORY AND TACTILE RECEPTORS IN CATFISH

1933 ◽  
Vol 16 (4) ◽  
pp. 685-693 ◽  
Author(s):  
Hudson Hoagland
Keyword(s):  
Facial Nerve ◽  
Bilateral Symmetry ◽  
Great Sensitivity ◽  
Gasserian Ganglion ◽  
Mechanical Stimuli ◽  
Tactile Receptors ◽  
Meat Juice ◽  
Cells Of Origin ◽  
Set Up ◽  
Sense Modalities

1. Receptors in the lips and barbels of the catfish Ameiurus nebulosus Les. are very sensitive to mechanical stimuli, giving large rapid (A-type) impulses in fibers of the facial nerve in response to touching the receptive surfaces and to movements of the water in which the preparation is immersed. 2. The great sensitivity of the barbels and lips to currents of water and the bilateral symmetry of the distribution of sensitivity of the facial nerve may serve as a basis for observed rheotropic orientation in the catfish. 3. Acetic acid, NaCl, and meat juice, dissolved in the water bathing the barbels and lips, set up impulses of very small and barely detectable potential in the fibers of the facial nerve. 4. It is suggested that the specificity of impulses for the two sense modalities may be correlated with the large size of the cells of origin of the axons in the Gasserian ganglion supplying tactile receptors and the small size of the cells of origin in the geniculate ganglion sending axons to taste-buds.

scholarly journals The Stimulus to Feeding in Anemonia Sulcata

1943 ◽  
Vol 20 (1) ◽  
pp. 6-13
Author(s):  
C. F. A. PANTIN ◽  
A. M. P. PANTIN
Keyword(s):  
Amino Acids ◽  
Bile Salts ◽  
Soxhlet Extraction ◽  
Great Sensitivity ◽  
Mechanical Stimuli ◽  
Feeding Response ◽  
Anemonia Sulcata ◽  
Set Up ◽  
Natural Foods ◽  
Active Substances

1. Feeding can be initiated in Anemonia sulcata by mechanical, chemical or electrical stimulation of the tentacles provided the stimulus sets up sufficiently prolonged excitation. Owing to rapid adaptation, mechanical stimuli rarely set up enduring excitation and inert objects are therefore usually rejected. Chemical stimuli set up prolonged excitation and food objects are therefore usually accepted. A series of electrical stimuli can produce rejection or feeding according to whether it is brief or prolonged. 2. The sensitivity of the tentacles varies greatly a different foods. It is greatest to animal foods. There is great sensitivity to certain kinds of mucus. 3. The active substances of natural foods are closely associated with protein. They fail to pass through a membrane which retains colloids. A feeding reaction can be obtained to food substances which appear to be insoluble in water. 4. Though the active substances of many natural foods are not in free solution, soluble derivatives of proteins, such as peptones and amino acids cause a feeding reaction. With pure proteins, the response of the cnida diminished. With amino acids, there is no cnida response. From this it follows that increased mechanical contact due to cnida discharge is not essential for excitation of the feeding response. 5. Fat, such as tristearin, and ethereal extracts of food are without effect. Alcoholic Soxhlet extraction of food yields a substance which causes the food reaction. Carbohydrates are without effect except in the case of glycogen, the action of which may be due to impurities. 6. The lower fatty acids, quinine and bile salts produce a withering contraction of the tentacles which differs from the response of the latter to food. The effect can be produced by prolonged electrical excitation at a higher frequency than that required for the feeding response and is therefore probably due to excessive stimulation. 7. The mouth responds to a greater variety of chemcial stimuli than the tentacles. The relative sensitivity of these organs to different chemcial stimuli is not the same, but for most agents the mouth is the more sensitive. Quinine, histamine and 10% bile salts excite the musculature of the mouth directly. 8. The range of chemical sensitivity in different coelenterates is discussed.

Novel Techniques for Trigeminal Neuralgia Including Trigeminal Neurostimulators

2018 ◽  
pp. 118-138
Author(s):  
Arvin R. Wali ◽  
Christian Lopez ◽  
Peter Abraham ◽  
Michael G. Brandel ◽  
David R. Santiago-Dieppa ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Facial Nerve ◽  
Patient Selection ◽  
Microvascular Decompression ◽  
Published Data ◽  
Gasserian Ganglion ◽  
Therapeutic Modalities ◽  
Trigeminal Nerve Stimulation ◽  
Surgical Options ◽  
Novel Therapeutic

Several innovative surgical options for the management of trigeminal neuralgia have emerged over the past 40 years. In addition to microvascular decompression, other techniques have been introduced for the treatment of trigeminal neuralgia and facial nerve pain. This chapter describes the following novel therapeutic modalities: endoscopic microvascular decompression, radiosurgery, radiofrequency, thermocoagulation, glycerol rhizotomoy, balloon compression, Gasserian ganglion stimulation, and subcutaneous trigeminal nerve stimulation. For each of these techniques, this chapter provides a description of the procedure, criteria for patient selection, and discusses published data regarding patient outcomes.

scholarly journals Pulmonary and respiratory tract receptors.

1982 ◽  
Vol 100 (1) ◽  
pp. 41-57
Author(s):  
J G Widdicombe
Keyword(s):  
Respiratory Tract ◽  
Large Diameter ◽  
Small Diameter ◽  
Spinal Reflexes ◽  
Mechanical Stimuli ◽  
Nerve Fibres ◽  
Motor Responses ◽  
Myelinated Fibres ◽  
Set Up ◽  
Stimulation Of

Nervous receptors in the lungs and respiratory tract can be grouped into four general categories. 1. Deep, slowly adapting end-organs, which respond to stretch of the airway wall and have large-diameter myelinated fibres; those in the lungs are responsible for the Breuer-Hering reflex. 2. Endings in and under the epithelium which respond to a variety of chemical and mechanical stimuli (i.e. are polymodal), usually with a rapidly adapting discharge, and with small-diameter myelinated fibres; they are responsible for defensive reflexes such as cough and sneeze, and for the reflex actions to inhaled irritants and to some respiratory disease processes. 3. Receptors with nonmyelinated nerve fibres which, being polymodal, are stimulated by tissue damage and oedema and by the mediators released in these conditions; these receptors may be similar in function to 'nociceptors' in other viscera, and set up appropriate reflexes as a reaction to respiratory damage. 4. Specialized receptors such as those for taste and swallowing, and those around joints and in skeletal muscle. Stimulation of any group of receptors may cause reflex changes in breathing (including defensive reflexes), bronchomotor tone, airway mucus secretion, the cardiovascular system (including the vascular bed of the airways), laryngeal calibre, spinal reflexes and sensation. The total pattern of motor responses is unique for each group of receptors, although it is probably unusual for one type of receptor to be stimulated in isolation. The variety of patterns of motor responses must reflect the complexity of brainstem organization of these systems.

scholarly journals EFFECTS OF CARBON DIOXIDE ENRICHMENT AND IRRADIANCE ON EX VITRO ROOTING, ACCLIMATIZATION AND SUBSEQUENT GROWTH OF MICROPROPAGATED APPLE AND BLUEBERRY.

HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 254A-254
Author(s):  
Marvin Pritts ◽  
Dorcas Isuta
Keyword(s):  
Survival Rate ◽  
Dry Weight ◽  
Great Sensitivity ◽  
High Light ◽  
Low Light ◽  
Light Levels ◽  
Significant Difference ◽  
Vigorous Growth ◽  
Set Up

Previous findings reveal that rooting and acclimatization of apple and blueberry plants is often difficult, inconsistent and inefficient. This experiment was set up in a fog chamber lo investigate the effects of CO2 enrichment (CDE) and irradiance on unrooted stage II microshoots. Two CO2 and 3 light levels tested were: 1350 +/- 150 (+ CDE), and 450 +/- 50 (- CDE) ppm; 30 +/- 5 (low), 55 + 10 (medium), and 100 + 20 (high) umolm-2s-1 respectively. Cultivars assessed were Berkeley and Northsky for blueberry. G65 and NY30 for apple. Blueberry microshoots acclimatized successfully and gave between 90 to 100% rooting and survival rate. Apple microshoots acclimatized and rooted slowly, exhibited great sensitivity to in vivo conditions and gave between 40 to 100% rooting and survival rate. High light induced photo-inhibition which disappeared after complete acclimatization. There was a significant difference between low light and the other two light levels. The effect of CDE was dependent on cultivar. In most cases, high light (-) CDE gave the most vigorous growth (highest plant dry weight and leaf area). There was a significant difference between (+) CDE and (-) CDE at low and medium light, but none at high light. Low light (-) CDE and medium light (+) CDE were superior over low light (+) CDE and medium light (-) CDE. respectively. Stalling out in apple microshoots was corrected by GA sprays.

Cells of origin of the branches of the facial nerve: A retrograde HRP study in the rabbit

1987 ◽  
Vol 178 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Ronald H. Baisden ◽  
Michael L. Woodruff ◽  
Dennis L. Whittington ◽  
Duane C. Baker ◽  
Amy E. Benson
Keyword(s):  
Facial Nerve ◽  
Cells Of Origin

The system specifying body position in the early development of Xenopus, and its response to early perturbations.

Development ◽  
1985 ◽  
Vol 89 (Supplement) ◽  
pp. 69-87
Author(s):  
Jonathan Cooke
Keyword(s):  
Early Development ◽  
Body Position ◽  
Bilateral Symmetry ◽  
The Body ◽  
Spatial Profile ◽  
Cell Stage ◽  
Larval Stages ◽  
Positional System ◽  
Set Up ◽  
Pattern Specification

Evidence is presented that the system setting up preliminary specifications for contributions to the axial body plan, across vegetal regions of the Xenopus embryo, acts in a widespread way at early stages. Mechanisms that regulate the spatial profile of this primary positional variable, and thus ensure the constancy and harmony of the body plans normally achieved, have lost this integrative ability by the 4-cell stage one hour after the plasm shifts that precede first cleavage and symmetrize the egg. Abnormal, partial or distorted profiles of the positional system across whole eggs or isolates, recorded by these times, are retained to give correspondingly partial or imbalanced mes/endodermal pattern at tailbud larval stages. There is evidence that subsequent ‘back-up’ positional interactions, which can heal gross positional discontinuities in isolated presumptive lateral half-eggs and so restore bilateral symmetry, also do this at the price of loss of complete pattern specification. This is probably because of an asymmetrical principle whereby relatively activated (dorsoanterior specified) material can raise the level of originally posterior material on contact, whereas the reverse interaction cannot occur. The observations are discussed in relation to apparently different behaviour in certain other amphibian embryos, and to our knowledge of other positional interactions, normal and also experimentally provoked, such as those that set up the germ layers.

The topology of cleavage patterns with examples from embryos of Nereis , Styela and Xenopus

1989 ◽  
Vol 325 (1225) ◽  
pp. 1-36 ◽  
Keyword(s):  
New York ◽  
Spatial Information ◽  
Bilateral Symmetry ◽  
Mechanical Forces ◽  
Spiral Cleavage ◽  
Cambridge University ◽  
Topological Maps ◽  
Ooplasmic Segregation ◽  
Set Up ◽  
Experimental Use

A theoretical scheme of cleavage is defined and used to construct topological maps of the cleavage patterns in embryos of Neris , Styela and Xenopus . The maps are a projection of the surface of the embryo showing every blastomere and every neighbour of each blastomere. They simplify the cleavage pattern. The cellular arrangements observed in blastulae can be reconstructed from the topological maps after specifying the mechanics that shape cellular arrangements. The mechanics of the rotations of blastomeres in the spiral cleavage of Nereis are found by these means. The maps of Nereis and Styela show the differences between spiral and bilateral cleavage. The map of Xenopus has bilateral symmetry and strongly resembles that of Styela . The variable cleavage patterns in Xenopus were recorded easily in topological maps. A numbering system for blastomeres of Xenopus , based on Conklin’s scheme for Styela , is described for experimental use. To explain the forms of cleavage patterns, we consider ways of dividing the plane into polygons each with six neighbours by lines drawn sequentially. Some ways have bilateral symmetry. We show how such partitioning of the plane can be transferred to a sphere. This allows cleavage patterns, which are a partitioning of a sphere, to be transferred back to the plane and so be compared with the partitioning that gives six neighbours. We conclude that cleavage patterns have features that bias the number of neighbours of each cell towards six. The forms of cleavage patterns, it is suggested, preserve spatial information in the cytoplasm, such as that set up during oogenesis and during ooplasmic segregation after fertilization, during the partitioning of the zygote into cells. They could be mechanically stable ways of dividing the zygotic cytoplasm that reduce stresses so blastomeres do not shift and disrupt the established spatial values. The apparently conflicting views of Thompson ( On growth and form . Cambridge University Press (1917)), who believed /cleavage patterns were determined solely by mechanical forces, and Wilson ( The cell in development and heredity . New York: Macmillan (1925)), who argued that cleavage patterns had promorphological significance, may thus be reconciled.

scholarly journals Repression of Dlx1/2 Signaling by Nolz-1/Znf503 is Essential for Parcellation of the Striatal Complex into Dorsal and Ventral Striatum

2018 ◽  
Author(s):  
Kuan-Ming Lu ◽  
Shih-Yun Chen ◽  
Hsin-An Ko ◽  
Ting-Hao Huang ◽  
Janice Hsin-Jou Hao ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Ventral Striatum ◽  
Dorsal Striatum ◽  
Clinical Importance ◽  
Projection Neurons ◽  
Striatal Neurons ◽  
Addictive Disorders ◽  
Striatal Projection Neurons ◽  
Cells Of Origin ◽  
Set Up

ABSTRACTThe division of the striatum into dorsal and ventral districts is of central clinical importance. The dorsal striatum is differentially affected in Huntington’s disease, dopamine in the ventral striatum is differentially spared in Parkinson’s disease, and human brain imaging studies implicate the ventral striatum in addictive disorders. If fits that the dorsal striatum contains the cells of origin of the direct and indirect basal ganglia pathways for motor control. The ventral striatum is a node in neural circuits related to motivation and affect. Despite these striking neurobiologic contrasts, there is almost no information about how the dorsal and ventral divisions of the striatum are set up during development. Here, we demonstrate that interactions between the two key transcription factors Nolz-1 and Dlx1/2 control the migratory paths of developing striatal neurons to the dorsal or ventral striatum. Moreover, these same transcription factors control the cell identity of striatal projection neurons in both the dorsal and ventral striatum including the cell origin of the direct and indirect pathways. We show that Nolz-1 suppresses Dlx1/2 expression. Deletion of Nolz-1 or over-expression of Dlx1/2 can produce a striatal phenotype characterized by withered dorsal striatum and a swollen ventral striatum, and that we can rescue this phenotype by manipulating the interactions between Nolz-1 and Dlx1/2 transcription factors. This evidence suggests that the fundamental basis for divisions of the striatum known to be differentially vulnerable at maturity is already encoded by the time embryonic striatal neurons begin their migrations into the developing striatum.

An analysis of the strain field in biaxial Flexcell membranes for different waveforms and frequencies

2008 ◽  
Vol 222 (8) ◽  
pp. 1235-1245 ◽  
Author(s):  
A Colombo ◽  
P A Cahill ◽  
C Lally
Keyword(s):  
Strain Curve ◽  
Cyclic Strain ◽  
Calibration Method ◽  
Peak Strain ◽  
Mechanical Stimuli ◽  
Stent Restenosis ◽  
System A ◽  
Set Up ◽  
Accuracy And Repeatability

Mechanical stimuli have been shown to affect cell behaviour in terms of proliferation, apoptosis, and protein expression. In terms of cardiovascular diseases, for example, endothelial and smooth muscle cells exposed to an abnormal strain environment have been associated with atherosclerosis and in-stent restenosis. The FX-4000™ system (Flexercell® Tension Plus System, Flexcell Corporation, McKeesport, Pennsylvania, USA) is an in-vitro system that is widely used to strain cells in order to evaluate their response to strain. The precision, accuracy, and repeatability of the strains controlled by the system are therefore crucial to analyse and interpret the results confidently. The aim of this study was to investigate the mechanical behaviour of the FX-4000™ Flexercell® six-well-plate silicon membranes for static and dynamic cyclic strains by measuring the maximum peak strain and analysing the change in the membrane deformation after cyclic strain for 0 h, 24 h, and 48 h at different strain amplitudes and frequencies. The results of the tests conducted demonstrate notable differences between the measured strains of the membranes in comparison with both the inputs and the outputs of the Flexcell® software. The calibration method used by Flexcell® International assumes that the strain values determined for a given vacuum pressure on the silicone membranes are reliable for different waveforms and frequencies. The data reported here clearly indicate that this is not the case. The results indicate that a unique calibration pressure—strain curve must be determined for each test given the viscoelastic nature of the Flexcell system. A new method to calibrate the machine in house was applied using new pressure—strain equations. This new calibration method has been presented and should enable researchers using the Flexcell® machine to set up their cell experiments more accurately.

scholarly journals Enhanced signal-to-noise ratios in frog hearing can be achieved through amplitude death

2013 ◽  
Vol 10 (87) ◽  
pp. 20130525 ◽  
Author(s):  
Kang-Hun Ahn
Keyword(s):  
High Sensitivity ◽  
Intrinsic Noise ◽  
Low Noise ◽  
Great Sensitivity ◽  
High Signal ◽  
Mechanical Stimuli ◽  
Signal To Noise ◽  
Amplitude Death ◽  
Hair Bundles

In the ear, hair cells transform mechanical stimuli into neuronal signals with great sensitivity, relying on certain active processes. Individual hair cell bundles of non-mammals such as frogs and turtles are known to show spontaneous oscillation. However, hair bundles in vivo must be quiet in the absence of stimuli, otherwise the signal is drowned in intrinsic noise. Thus, a certain mechanism is required in order to suppress intrinsic noise. Here, through a model study of elastically coupled hair bundles of bullfrog sacculi, we show that a low stimulus threshold and a high signal-to-noise ratio (SNR) can be achieved through the amplitude death phenomenon (the cessation of spontaneous oscillations by coupling). This phenomenon occurs only when the coupled hair bundles have inhomogeneous distribution, which is likely to be the case in biological systems. We show that the SNR has non-monotonic dependence on the mass of the overlying membrane, and find out that the SNR has maximum value in the region of amplitude death. The low threshold of stimulus through amplitude death may account for the experimentally observed high sensitivity of frog sacculi in detecting vibration. The hair bundles' amplitude death mechanism provides a smart engineering design for low-noise amplification.

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