An Electrophysiological Approach to the Study of Chemical Sensory Reception in Certain Insects

1953 ◽  
Vol 85 (5) ◽  
pp. 182-189 ◽  
Author(s):  
John A. Chapman ◽  
Roderick Craig
Keyword(s):  
Electrical Activity ◽  
Olfactory Nerve ◽  
Nerve Fibers ◽  
Receptor Activity ◽  
Sensory Receptors ◽  
The Past ◽  
Electrical Potentials ◽  
Sensory Reception

In the past twenty years or so many investigators have studied amplified electrical activity from nerve fibers supplving sensory receptors in many animals, including insects (see 2, 5, 8, 16, 19). With this technique much information has been secured concerning the characreristics of mechanical receptors (touch, pressure, sound, etc.) and photoreceptors. To a much lesser extent temperature, pain, taste and other chemical receptor activity in vertebrates has been studied although no electrical potentials appear to have been recorded from individual olfactory nerve fibers in any organism.

scholarly journals The glass micropipette electrode: A history of its inventors and users to 1950

2017 ◽  
Vol 149 (4) ◽  
pp. 417-430 ◽  
Author(s):  
Allan H. Bretag
Keyword(s):  
Electrical Activity ◽  
Plant Cells ◽  
Living Cells ◽  
Cellular Level ◽  
Nerve Fibers ◽  
Mechanistic Explanations ◽  
Electrical Potentials ◽  
Micro Tool ◽  
History Of ◽  
Glass Micropipette

Soon after the glass micropipette was invented as a micro-tool for manipulation of single bacteria and the microinjection and microsurgery of living cells, it was seen to hold promise as a microelectrode to stimulate individual cells electrically and to study electrical potentials in them. Initial successes and accurate mechanistic explanations of the results were achieved in giant plant cells in the 1920s. Long known surface electrical activity in nerves and muscles was only resolved at a similar cellular level in the 1930s and 1940s after the discovery of giant nerve fibers and the development of finer tipped microelectrodes for normal-sized cells.

Transducer for recording electrical and mechanical chronic intestinal activity

1976 ◽  
Vol 41 (6) ◽  
pp. 942-945 ◽  
Author(s):  
A. Lambert ◽  
R. Eloy ◽  
J. F. Grenier
Keyword(s):  
Electrical Activity ◽  
Wheatstone Bridge ◽  
Displacement Transducer ◽  
Intestinal Wall ◽  
Mechanical Activity ◽  
Strain Gauges ◽  
Mechanical Displacement ◽  
Electrical Potentials ◽  
Intestinal Activity ◽  
Long Duration

An extraluminal displacement transducer has been developed for simultaneously recording the mechanical activity in two perpendicular directions andthe electrical activity of the intestinal serosa. The length variations in two perpendicular directions were measured by means of strain gauges bounded on two pairs of lamellae embedded in a rigid stand. The electrical activity was recorded by means of four electrodes situated at the extremity of these lamellae. The electrical gauges of each pair of lamellae are connected to form a Wheatstone bridge. This device allows establishment of a correlation between the mechanical displacement of the intestinal wall serosa and electrical potentials by means of studies of long duration.

scholarly journals The Electrical Activity of the Orbicularis Oris Muscle in Children with Down Syndrome—A Preliminary Study

2021 ◽  
Vol 10 (23) ◽  
pp. 5611
Author(s):  
Liliana Szyszka-Sommerfeld ◽  
Magdalena Sycińska-Dziarnowska ◽  
Krzysztof Woźniak ◽  
Monika Machoy ◽  
Sławomir Wilczyński ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Electrical Activity ◽  
Healthy Children ◽  
Exclusion Criteria ◽  
Children With Down Syndrome ◽  
Electrical Potentials ◽  
Study Results ◽  
Orbicularis Oris Muscle ◽  
Preliminary Study ◽  
Muscular Effort

The aim of this study was to assess the electrical activity of the superior (SOO) and inferior (IOO) orbicularis oris muscles in children with Down syndrome (DS) and in children without DS. After applying the inclusion and exclusion criteria, 30 subjects were eligible to participate in the later stages of the research—15 subjects with DS (mean age 10.1 ± 1.1) and 15 healthy controls (mean age 9.8 ± 1.0). The electrical potentials of the SOO and IOO muscles were recorded using a DAB-Bluetooth electromyography machine (Zebris Medical GmbH, Germany) during the following tasks: At clinical rest, saliva swallowing, lip protrusion, lip compression, and production of the syllable/pa/. The Mann–Whitney U test was conducted to compare the study results between the groups. An analysis of the electromyographical (EMG) recordings showed that the electrical activity of the orbicularis oris muscle in children with DS and lip incompetence was significantly higher compared to healthy children during saliva swallowing, lip compression, and when producing the syllable/pa/, and this may suggest greater muscular effort due to the need to seal the lips during these functional conditions.

Dendritic origin of late events in optical recordings from salamander olfactory bulb

1992 ◽  
Vol 68 (3) ◽  
pp. 786-806 ◽  
Author(s):  
A. R. Cinelli ◽  
B. M. Salzberg
Keyword(s):  
Olfactory Bulb ◽  
Time Course ◽  
Slow Component ◽  
Field Potential ◽  
Olfactory Nerve ◽  
Nerve Fibers ◽  
Dependent Manner ◽  
Gamma Aminobutyric Acid ◽  
Direct Stimulation ◽  
Compound Action

1. Optical recordings of membrane-potential changes were used to characterize the origin and properties of the electrical signals from the dendritic level in slices of the salamander olfactory bulb. 2. The optical events were correlated with field-potential waves recorded simultaneously. Both responses exhibited patterns similar to those found in other species. 3. Orthodromic stimulation evoked a compound action potential in the olfactory nerve fibers, followed by two additional principal waves (N1 and N2). These field-potential waves reflected excitatory postsynaptic potentials at the primary mitral/tufted and granule cell dendrites, respectively. 4. Extrinsic optical signals from horizontal slices stained with the pyrazo-oxonal dye RH-155 showed a characteristic sequence of depolarizing and hyperpolarizing events. All of the signals exhibited a wavelength dependence expected for this dye and were abolished in the presence of high K+ in the bath. 5. According to their time courses, depolarizing responses under normal recording conditions were divided into two components, fast and slow. Orthodromic stimuli evoked a fast presynaptic response that represents synchronous compound action potentials from olfactory nerve fibers. At subglomerular levels, additional fast responses could often be recorded at the peri/subglomerular level and in the mitral/tufted somata region. These postsynaptic responses partially coincided with the rising phase of a different depolarizing signal, a slow component characterized by its prolonged time course. 6. With orthodromic stimulation, this slow signal attained its largest amplitude in the zone between the glomeruli and the superficial part of the external plexiform layer (EPL). Antidromic stimuli evoked a signal with some similarities to the one evoked orthodromically, but originating in deeper EPL regions. 7. Slow components were characterized by their Ca dependence. Low Ca2+ medium, or calcium channel blockers, suppressed this optical component, whether evoked orthodromically, antidromically, or by direct stimulation. In addition, Ba2+ (2.5–3.6 mM) in the bath did not abolish these responses, suggesting that they do not reflect a glial depolarization in response to elevated extracellular K+ concentration ([K+]o). 8. Locally applied stimuli next to the glomerular layer elicited these signals in 5–10 microM tetrodotoxin (TTX) or in low extracellular Na+ concentration ([Na+]o) medium, but antidromic or orthodromic stimuli failed to evoke the response under these conditions. The sizes of the responses to local stimuli remained constant, but an increase in their duration was observed in either TTX or low [Na+]o. 9. gamma-Aminobutyric acid (GABA) and baclofen reduced the size of the slow components in a dose-dependent manner.(ABSTRACT TRUNCATED AT 400 WORDS)

Electrical pacemakers of canine proximal colon are functionally innervated by inhibitory motor neurons

1989 ◽  
Vol 256 (3) ◽  
pp. C466-C477 ◽  
Author(s):  
T. K. Smith ◽  
J. B. Reed ◽  
K. M. Sanders
Keyword(s):  
Electrical Activity ◽  
Motor Neurons ◽  
Circular Muscle ◽  
Proximal Colon ◽  
Nerve Fibers ◽  
Pacemaker Activity ◽  
Intracellular Recordings ◽  
Potential Oscillations ◽  
Circular Layer ◽  
Different Populations

Pacemaker activity in the canine proximal colon occurs at the submucosal and myenteric borders of the circular layer [Am. J. Physiol. 252 (Cell Physiol. 21): C215-C224 and C290-C299, 1987]. The present study investigated the neural regulation of rhythmic electrical activity. Spontaneous inhibitory junction potentials (IJPs) were observed in intracellular recordings from circular muscle cells near the myenteric border. The amplitudes of these events decayed with distance through the circular layer. Stimulation at the myenteric plexus surface evoked IJPs that mimicked the spontaneous events. Stimulation at the submucosal surface evoked IJPs in adjacent cells that were of shorter duration and of different waveform than myenteric IJPs. Amplitudes of IJPs evoked by stimulation near either surface decayed with distance from the site of stimulation. The decay functions for IJPs were essentially identical to the decay of spontaneous slow waves or myenteric potential oscillations. Spontaneous and evoked IJPs affected the amplitudes, durations, and patterns of ongoing rhythmic electrical activity. The data suggest that myenteric and submucosal pacemaker populations may be innervated by different populations of inhibitory nerve fibers. Innervation appears to be heterogeneous with dense populations of inhibitory nerve fibers predominantly located in the pacemaker regions. Neural regulations of pacemaker activity influences rhythmic electrical activity throughout the muscularis.

Factors determining the frequency content of the electromyogram

1983 ◽  
Vol 55 (2) ◽  
pp. 392-399 ◽  
Author(s):  
H. Kranz ◽  
A. M. Williams ◽  
J. Cassell ◽  
D. J. Caddy ◽  
R. B. Silberstein
Keyword(s):  
Electrical Activity ◽  
Action Potentials ◽  
Nerve Fibers ◽  
Frequency Content ◽  
Muscle Properties ◽  
Spectral Content ◽  
Unit Discharge ◽  
Compound Action Potentials ◽  
Motor Unit Discharge ◽  
Compound Action

The contribution of central and peripheral factors to the frequency content of the electromyogram was examined in 10 subjects performing maximal 45-s contractions of thenar muscles. The median frequencies (Fm) of surface-recorded electromyograms and compound action potentials were similar early (P greater than 0.6) and late (P greater than 0.5) in the contractions. There was a mean decrease in the Fm during contraction of 39% for electromyograms and 35% for compound potentials (P greater than 0.1). The Fm of electromyograms increased 11% (P less than 0.02) in only the 1st s of contraction as force was raised from 25 to 100% of maximum. Only one of five subjects showed evidence of increasing synchronization of motor unit discharge during contraction. There was no evidence that delay or dispersion of action potential propagation in terminal nerve fibers or at the neuromuscular junction had a significant effect on frequency content. The findings indicated that the spectral content of muscle electrical activity, and its shift during contraction, primarily reflects intrinsic muscle properties.

scholarly journals OLFACTORY NERVE FIBERS

1956 ◽  
Vol 39 (4) ◽  
pp. 473-496 ◽  
Author(s):  
Herbert S. Gasser ◽  
Keyword(s):  
Action Potential ◽  
Cross Sections ◽  
Plasma Membranes ◽  
Size Variation ◽  
Olfactory Nerve ◽  
Nerve Fibers ◽  
Bipolar Cells ◽  
Basal Cells ◽  
Sustentacular Cells ◽  
Physiological Properties

Cross sections of olfactory nerves present a unique appearance. They indicate the presence of large numbers of very small nerve fibers, with a modal diameter of about 0.2 µ and a narrow range for their size variation. From one side of the nasal septum of a pig the yield of fibers was estimated at 6,000,000; the number arising from the turbinates would be considerably larger. The fibers are attached to the membranes of the Schwann sheaths in large bundles through mesaxons longer and more branched than those that have been seen in other nerves. Continuity of the axons between the nerves and the bipolar cells was traced in an examination of the olfactory mucous membrane; and the indication of a one-to-one relationship between cells and axons was reinforced by a comparative count. After the axons leave the bipolar cells they become incased in the central projections of the sustentacular cells. Where the latter come into contact with the basal cells the axons emerge to push back the plasma membranes of the basal cells in the first step in acquiring their nerve sheaths. Later steps are described. When the axons are delivered by the basal cells to the collecting Schwann tubes, they are already aggregated into small bundles with sheaths fundamentally the same as those they will possess until they are delivered to the glia in the olfactory bulb. Some of the aspects of the cytology of the bipolar cells and adjoining sustentacular cells are described. A survey of the physiological properties of olfactory nerve fibers was made in some experiments on the olfactory nerve of the pike. Almost all of the action potential is encompassed within a single elevation, manifesting at its front a conduction velocity of 0.2 m./sec. For a comparison, the last elevation in the C action potential in the sciatic nerve of the frog is cited as an example of conduction at the same velocity. Though expressed through long time constants, the properties of the pike olfactory fibers conform to the generalized schema for properties of vertebrate nerve fibers. This conformity signalizes that they differ from the exceptional properties of the unmedullated fibers of dorsal root origin. An afferent function for unmedullated nerve fibers does not imply that the fibers concerned are alike in their physiological properties.

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