An Isolated Insect Ganglion-Nerve-Muscle Preparation

1966 ◽  
Vol 44 (3) ◽  
pp. 413-427
Author(s):  
GRAHAM HOYLE
Keyword(s):  
Motor Nerve ◽  
Output Frequency ◽  
Direct Stimulation ◽  
Mechanical Responses ◽  
Inhibitory Conditioning ◽  
Metathoracic Ganglion ◽  
Single Fibres ◽  
Preganglionic Stimulation ◽  
Nerve Muscle ◽  
Whole Muscle

1. A preparation is described which consists of an isolated locust metathoracic ganglion, together with one motor nerve and the skeletal muscle which it supplies (the anterior coxal adductor) in a state suitable for tension recording. 2. Mechanical responses were recorded from the whole muscle, or bundles of fibres and electrical responses of single fibres were recorded intracellularly. Some fibres were found in the muscle which have unusual properties. A single excitatory axon supplies the muscle. 3. Preganglionic stimulation applied to cut nerve trunks may excite an inhibitory-conditioning axon supplying the same muscle. 4. Direct stimulation of the motor nerve was combined with preganglionic stimulation in order to excite the two axons, and their interaction in relation to contraction of the muscle was studied. 5. The preparation shows spontaneous activity in the single excitatory axon supplying the muscle. 6. Various preganglionic stimulations were found to cause prolonged changes in the spontaneous motor output. By correlating the stimuli to the output in certain ways, long-lasting changes in mean output frequency were obtained. These may be regarded as a simple form of learning.

scholarly journals The actions of eserine-like compounds upon frog’s nerve-muscle preparations, and the blocking of neuromuscular conduction

1940 ◽  
Vol 129 (856) ◽  
pp. 392-411 ◽  
Keyword(s):  
Neuromuscular Transmission ◽  
Motor Nerve ◽  
Calcium Content ◽  
Recovery Process ◽  
Direct Stimulation ◽  
Rate Of Recovery ◽  
Nerve Muscle ◽  
Minimum Interval ◽  
Site Of Stimulation ◽  
Stimulation Of

The actions of prostigmine, eserine, and the dimethylcarbamic ester of 8-hydroxymethylquinolinium methylsulphate upon the frog's isolated nervesartorius preparation have been examined by a method developed by Lucas (1911). With Ringer-soaked preparations from frogs kept at 14-18°C for some days before use the minimum interval at which two shocks applied to the nerve could elicit a summated muscular response was about 20% longer than the absolute refractory period of the nerve. Any of the above-mentioned compounds prolonged the minimum interval for a summated response, but caused the time at which an extra interpolated shock began to cut down the response to the final shock to become only a little later. Curarine or atropine reversed the prolongation of minimum interval. By the same method, the actions of the same eserine-like compounds upon preparations which had been treated with Ringer's solution of half the usual calcium content were examined. Either before or after treatment, it was impossible to cut down the muscular response by interpolating an extra shock. The action of prostigmine upon Ringer-soaked preparations was examined by a method developed by Adrian (1913), involving determination of the rate of recovery of excitability in the motor nerve at the site of stimulation and in the remaining more peripheral part of the preparation. Prostigmine influenced little the recovery process at the site of stimulation, whereas it prolonged the slower and more peripheral recovery process. Curarine reversed the prolongation of the more peripheral recovery. With Ringer-soaked preparations, during the block of neuromuscular transmission produced by rapid repetitive stimulation of the nerve, the response of the muscle to direct stimulation was reduced. If, however, neuromuscular transmission had been blocked by curarine, stimulation of the nerve did not reduce the response of the muscle to direct stimulation.

The Electrical and Mechanical Events of Neuro-Muscular Transmission in the Cockroach, Periplaneta Americana (L.)

1950 ◽  
Vol 27 (1) ◽  
pp. 1-13
Author(s):  
KENNETH D. ROEDER ◽  
ELIZABETH A. WEIANT
Keyword(s):  
Structural Changes ◽  
Periplaneta Americana ◽  
Mechanical Response ◽  
Motor Nerve ◽  
Potential Gradient ◽  
Positive Sign ◽  
Direct Stimulation ◽  
Bipolar Recording ◽  
Nerve Muscle ◽  
Muscle Potential

1. A nerve-muscle preparation in the metathorax of the cockroach is described. It consists of the second tergal muscle of the trochantin (muscle 162 of Carbonell) innervated by a branch of nerve 3 A. Electrical changes are recorded from electrodes on the muscle surface, and the onset of contraction is registered by the stylus of a piezo-electric pick-up. 2. With low (3-5 per sec.) stimulation rates at room temperature the neuromuscular delay is less than 1.2 msec., and the latent period of contraction about 3.0 msec. The muscle potential is 4-5 msec. in duration, positive in sign at the muscle surface, and monophasic in form with either monopolar or bipolar recording. During excitation a potential gradient develops along the muscle, the greatest positivity being in the middle near the point of nerve entry. 3. Neither electrical nor mechanical response show gradations with changes in stimulus strength or frequency. No facilitation is evident, and the response appears to be due to stimulation of a single quick motor nerve fibre. 4. In order to study the effects of direct stimulation nerve 3 was sectioned and allowed to degenerate. All trace of the peripheral nerve stump was lost after 3 days, when the muscle became completely inexcitable to all forms of electrical stimulation. There were no gross structural changes which would account for this loss of excitability. 5. It is concluded that the recorded muscle potential in the cockroach is analogous to the vertebrate end-plate potential, being the sum of local muscle potentials developing simultaneously in several fibres, and sequentially at several innervation points along the same fibre. Conduction within the muscle is carried out entirely by motor nerve fibres. 6. Possible causes of the positive sign of the muscle during activity are discussed.

Pharmacological Properties of Excitatory Neuromuscular Synapses in the Locust

1968 ◽  
Vol 49 (2) ◽  
pp. 341-361
Author(s):  
P. N. R. USHERWOOD ◽  
P. MACHILI
Keyword(s):  
Muscle Fibres ◽  
Amino Group ◽  
Mechanical Responses ◽  
Neuromuscular Synapses ◽  
Level Of Activity ◽  
Excitatory Activity ◽  
Wide Range ◽  
Nerve Muscle ◽  
Related Compounds ◽  
Stimulation Of

1. The effects of a wide range of amino acids and related compounds on retractor unguis nerve-muscle preparations from the locust, grasshopper and cockroach have been investigated. 2. L-glutamate is the most active excitatory substance. The presence of two acidic groups and one amino group is essential for excitatory activity while the position of the amino group is of some importance in determining the level of activity. 3. When L-glutamate is applied iontophoretically to the muscle fibres, ‘glutamate’ depolarizations are recorded only at the synaptic sites. Other evidence that the action of glutamate is restricted to the synaptic sites is presented. 4. Perfusion of isolated locust retractor unguis nerve-muscle preparations with locust haemolymph does not markedly affect the neurally evoked mechanical responses. It appears that locust haemolymph contains little ‘free’ L-glutamate. 5. Four acidic amino aids have been identified in the perfusate from isolated retractor unguis preparations namely, glycine, alanine, aspartate and L-glutamate. However, only L-glutamate increases in concentration during stimulation of the retractor unguis nerve.

Repair of Motor Nerve Defects: Comparison of Suture and Fibrin Adhesive Techniques

1989 ◽  
Vol 100 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Shigeki Nishihira ◽  
Thomas V. McCaffrey
Keyword(s):  
Sciatic Nerve ◽  
Motor Nerve ◽  
Nerve Repair ◽  
Suture Technique ◽  
Nerve Graft ◽  
Tissue Adhesive ◽  
Muscle Twitch ◽  
Fibrin Adhesive ◽  
Fibrin Tissue Adhesive ◽  
Nerve Muscle

Two groups of rats were used to evaluate the results of nerve repair using fibrin tissue adhesive. In one group of 10 rats, a simple neurotomy of the sciatic nerve was performed. In the second group of 10 rats, a 1-cm segment of sciatic nerve was excised bilaterally and used as an autogenous nerve graft. The neurotomy and the nerve graft were repaired on one side by microsurgical suture technique using 10-0 nylon suture. The opposite side was repaired using fibrin adhesive. The results of the repair were assessed at 12 weeks. Functional assessment of nerve regeneration was performed in those rats with intact repair sites. Nerve-muscle twitch strengths were not significantly different ( p > 0.05) between nerves repaired using suture and fibrin adhesive; however, compound active potential parameters were significantly better in nerve grafts repaired using suture technique ( p < 0.05).

CONDUCTION BLOCK OF TERMINAL SOMATIC MOTOR FIBERS IN TICK PARALYSIS

1960 ◽  
Vol 38 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Maurice F. Murnaghan
Keyword(s):  
Motor Nerve ◽  
Conduction Block ◽  
Nerve Impulse ◽  
Nerve Fibers ◽  
Treated Animal ◽  
Direct Stimulation ◽  
High Potassium ◽  
Control Value ◽  
Choline Acetylase ◽  
Stimulation Of

In the perfused anterior tibial muscle of the tick-paralyzed dog acetylcholine in excess of the control value is not liberated on stimulation of the peroneal nerve; in the normal muscle 7 μμg of acetylcholine is liberated per nerve volley. The paralysis is evidently not due to defective synthesis of acetylcholine because acetylcholine is liberated in control and high-potassium perfusates, the choline acetylase activity and the acetylcholine content of lumbar ventral roots and peroneal nerves do not differ from that in normal dogs, and the tick-paralyzed muscle differs from that in the hemicholinium-treated animal in its response to a train of nerve pulses after previous tetanization. As somatic motor nerve fibers in the paralyzed dog have previously been shown to conduct a nerve impulse and the factors required for acetylcholine release at the nerve terminal apparently are not absent in the paralyzed animal, the mechanism of the paralysis is probably due to an inability of the nerve impulse to traverse the terminal presynaptic fibers. The 'lesion' evidently extends to the end of the presynaptic fiber, i.e. more distally than in botulism, because direct stimulation of the tick-paralyzed muscle fails to liberate acetylcholine.

scholarly journals Distribution of N-CAM in synaptic and extrasynaptic portions of developing and adult skeletal muscle.

1986 ◽  
Vol 102 (3) ◽  
pp. 716-730 ◽  
Author(s):  
J Covault ◽  
J R Sanes
Keyword(s):  
Schwann Cells ◽  
Motor Nerve ◽  
Cell Types ◽  
Nerve Terminals ◽  
Electron Microscopic ◽  
Adult Skeletal Muscle ◽  
Adult Rat ◽  
Embryonic Muscle ◽  
Nerve Muscle

Previous studies of denervated and cultured muscle have shown that the expression of the neural cell adhesion molecule (N-CAM) in muscle is regulated by the muscle's state of innervation and that N-CAM might mediate some developmentally important nerve-muscle interactions. As a first step in learning whether N-CAM might regulate or be regulated by nerve-muscle interactions during normal development, we have used light and electron microscopic immunohistochemical methods to study its distribution in embryonic, perinatal, and adult rat muscle. In embryonic muscle, N-CAM is uniformly present on the surface of myotubes and in intramuscular nerves; N-CAM is also present on myoblasts, both in vivo and in cultures of embryonic muscle. N-CAM is lost from the nerves as myelination proceeds, and from myotubes as they mature. The loss of N-CAM from extrasynaptic portions of the myotube is a complex process, comprising a rapid rearrangement as secondary myotubes form, a phase of decline late in embryogenesis, a transient reappearance perinatally, and a more gradual disappearance during the first two postnatal weeks. Throughout embryonic and perinatal life, N-CAM is present at similar levels in synaptic and extrasynaptic regions of the myotube surface. However, N-CAM becomes concentrated in synaptic regions postnatally: it is present in postsynaptic and perisynaptic areas of the muscle fiber, both on the surface and intracellularly (in T-tubules), but undetectable in portions of muscle fibers distant from synapses. In addition, N-CAM is present on the surfaces of motor nerve terminals and of Schwann cells that cap nerve terminals, but absent from myelinated portions of motor axons and from myelinating Schwann cells. Thus, in the adult, N-CAM is present in synaptic but not extrasynaptic portions of all three cell types that comprise the neuromuscular junction. The times and places at which N-CAM appears are consistent with its playing several distinct roles in myogenesis, synaptogenesis, and synaptic maintenance, including alignment of secondary along primary myotubes, early interactions of axons with myotubes, and adhesion of Schwann cells to nerve terminals.

Propagation of electric activity in motor nerve terminals

1965 ◽  
Vol 161 (985) ◽  
pp. 453-482 ◽  
Keyword(s):  
Motor Nerve ◽  
Electric Activity ◽  
Muscle Fibres ◽  
Nerve Terminals ◽  
Terminal Branch ◽  
Direct Stimulation ◽  
Motor Nerve Terminals ◽  
End Plate ◽  
Synaptic Terminals ◽  
Set Up

External micro-electrodes were used to stimulate non-myelinated motor nerve terminals and to record pre- and post-synaptic responses at the neuromuscular junction of the frog. The synaptic terminals of the motor axon are electrically excitable. Antidromic nerve impulses can be set up by local stimulation of terminals along the greater part of their length. Presynaptic spikes can be recorded from the non-myelinated terminal parts of motor axons. As the impulse proceeds towards the tip of the terminal branch, the shape of the spike changes from a predominantly negative to a predominantly positive-going wave. Similar changes occur in muscle fibres near their tendon junctions, and can be attributed to the special local-circuit conditions at the ‘closed end’ of a fibre. The velocity of impulse propagation in motor nerve endings was determined by three different methods: ( a ) from the latency of antidromic nerve spikes elicited at different points along terminals, ( b ) from two-point recording of spikes along a terminal, ( c ) from the differential latency of focal end-plate potentials recorded at two spots of a myoneural junction. The average velocity obtained by these methods was approximately 0.3 m/s at 20 °C. Extracellular muscle fibre spikes recorded at junctional spots showed no significant differences from those recorded elsewhere, provided the spikes were initiated by direct stimulation and did not coincide with transmitter action. Direct current polarization produces a graded increase in frequency of miniature end-plate potentials when the endings are being depolarized, and sudden high-frequency bursts during excessive hyperpolarization. External two-point recording shows that these bursts arise independently at different spots of the synaptic terminals.

The Effects of Curare in the Cockroach

1970 ◽  
Vol 52 (3) ◽  
pp. 583-592
Author(s):  
K. J. FRIEDMAN ◽  
A. D. CARLSON
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Nerve ◽  
Nerve Fibres ◽  
Affected Area ◽  
Metathoracic Ganglion ◽  
The Central Nervous System ◽  
Mechanical Studies

1. The nature of insect curarization has been investigated in the cockroach, P. americana. Mechanical studies of leg contraction revealed that dTC, whether injected into the abdomen, injected into a leg or applied to the metathoracic ganglion, produces failure of contraction. 2. The contraction failure caused by injecting dTC into a leg or by applying dTC to the metathoracic ganglion could be reversed by washing the drug out of the affected area. 3. The central nervous system does not appear to be essential for curare-induced contraction failure. The contraction of metathoracic legs deprived of their metathoracic ganglion is abolished in the presence of curare. 4. Since curare produces contraction failure when applied to the metathorax and when injected into a leg, the site of curare action must be present in both these locations. The motor nerve fibres are present in both these locations and it is proposed that contraction failure is due to the action of curare on these fibres.

The Giant Fibre Reflex of the Earthworm, Lumbricus Terrestris L

1962 ◽  
Vol 39 (2) ◽  
pp. 219-227
Author(s):  
M. B. V. ROBERTS
Keyword(s):  
Nerve Cord ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Muscle Preparation ◽  
Direct Stimulation ◽  
Giant Fibre ◽  
Low Threshold ◽  
Giant Fibres ◽  
Nerve Muscle ◽  
Stimulation Of

1. A nerve-muscle preparation including the longitudinal musculature and the giant fibres in the nerve cord of the earthworm is described. 2. Direct stimulation of the nerve cord with single shocks of increasing intensity results in two types of response: (a) a low threshold, very small twitch, resulting from a single impulse in the median giant fibre, and (b) a higher threshold, slightly larger twitch, resulting from single impulses in the median and lateral giant fibres. Both responses are highly susceptible to fatigue. 3. Stimulation of the body surface evokes a much more powerful contraction which is associated with a burst of impulses in the giant fibre. The strength of the contraction depends upon the number of impulses in the burst and this in turn upon the intensity and duration of the stimulus.

A comparison of the antidotal effects of three oximes against an organophosphate on chick skeletal muscle

2021 ◽  
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Motor Nerve ◽  
Toxic Effects ◽  
Hi 6 ◽  
Msec Duration ◽  
Organophosphorus Poisoning ◽  
Pre Treatment ◽  
Nerve Muscle ◽  
Time Of Administration

Background: One of the most toxic effects of organophosphorus poisoning (OP) is the paralysis of skeletal muscles. The oximes are a group of available antidotes. This study investigated the effects of different concentrations of paraoxon on the function of skeletal muscle and reversal or prevention of these effects by three different oximes (i.e., pralidoxime, obidoxime, and HI-6). Materials and Methods: This study was conducted based on the chicken biventer cervices (CBC) nerve-muscle preparation and the use of twitch tension recording technique. The twitches of the CBC were evoked by stimulating the motor nerve at 0.1 Hz with pulses of 0.2 msec duration and a voltage greater than that required to produce the maximum response. Moreover, twitches and contractures were recorded isotonically using Grass Biosystems. Results: Paraoxon at 0.1 µM induced a significant increase (more than 100%) in the twitch amplitude, while higher concentrations (0.3 and 1µM) induced partial or total contracture. Therefore, paraoxon at a concentration of 0.1 µ M was used to examine the capability of oximes to prevent or reverse its effects. Pralidoxime, obidoxime, and HI-6 dose-dependently prevented (when it was used as pre-treatment, 20 min before or at the same time of administration of the toxin) and reversed (when it was used as post-treatment, 20 min after the administration of the toxin) the effect of paraoxon. Conclusion: In conclusion, these results revealed that oximes were very useful in the prevention and reversal of the OP toxic effects on the skeletal muscle. Moreover, it was suggested that oximes were more effective when used as pre-treatment. Pralidoxime was more potent than obidoxime and HI-6. The HI-6, which is a newer oxime, was unexpectedly less effective than the other two.

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