Transmission Through the Last Abdominal Ganglion of the Dragonfly Nymph, Anax Imperator

1960 ◽  
Vol 37 (4) ◽  
pp. 832-844
Author(s):  
ANN FIELDEN
Keyword(s):  
Spinal Cord ◽  
Motor Neurons ◽  
Temporal Summation ◽  
Ventral Nerve Cord ◽  
Abdominal Ganglion ◽  
Insect Nervous System ◽  
Dragonfly Nymph ◽  
Thoracic And Abdominal ◽  
The Relationship ◽  
Stimulation Of

1. In the last abdominal ganglion of the dragonfly nymph afferent fibres from tactile endings on the paraprocts synapse with large ascending fibres in the ventral nerve cord. The latter run the length of the cord and synapse with efferent fibres in the segmental nerves of the thoracic and abdominal ganglia. The evasion response is mediated by this pathway and can be elicited by electrical stimulation of the nerves from the paraprocts. 2. The synapses between tactile afferents and ascending fibres show delays of 2.0-4.5 msec. and transmit synchronously to frequencies of 50-60/sec. There is no evidence for facilitation at these synapses, but facilitation and/or temporal summation is of importance at the efferent synapses which appear more labile in their properties. 3. Stimulation of the paraproct nerves shows the existence of a reflex connexion between afferents and efferents of the same nerve comparable to that of the vertebrate spinal cord. This provides a preparation for a study of the relationship between sensory and motor neurons in the insect nervous system. 4. Transmission through the last abdominal ganglion and cord is compared with that in the cockroach and locust.

The Activity of Single Motor Fibres in Arthropods I. The Dragonfly Nymph

1965 ◽  
Vol 42 (3) ◽  
pp. 447-461
Author(s):  
ANN KNIGHTS
Keyword(s):  
Electrical Stimulation ◽  
Temporal Summation ◽  
Reciprocal Relationship ◽  
Response Patterns ◽  
Insect Muscle ◽  
Frequency Sensitivity ◽  
Single Motor ◽  
Dragonfly Nymph ◽  
Central Inhibition ◽  
Stimulation Of

1. Responses to mechanical and electrical stimulation have been investigated in single motor fibres dissected in the segmental nerves of the dragonfly nymph. 2. A large proportion of fibres possessed a background discharge which was often accelerated of inhibited on stimulation. Examples of central inhibition were common. 3. Efferent responses varied in type, delay and regularity, both with the input under stimulation and with the frequency and intensity of the volley. The majority of fibres responded to stimulation of more than one nerve root. 4. In many motor fibres changes in the parameters of stimulation demonstrated a reciprocal relationship between and frequency. An enhanced responsiveness occurred with frequency increases in the range of 10-100/sec. indicatind a considerable importance of temporal summation/facilitation. 5. The characteristic frequency-sensitivity of motor fibres and the variability of their response patterns are discussed in relation to the control of insect muscle.

Effect of multisegmental electrical stimulation in combination with proprioceptive stimulation of the spinal cord on changes in reflex excitability of motor neurons

2021 ◽  
Author(s):  
R.N. Yakupov ◽  
S.S. Ananiev ◽  
D.A. Pavlov ◽  
I.V. Antipov ◽  
M.V. Balykin
Keyword(s):  
Neural Networks ◽  
Spinal Cord ◽  
Electrical Stimulation ◽  
Motor Neurons ◽  
Movement Disorders ◽  
Reflex Excitability ◽  
Central Origin ◽  
Proprioceptive Stimulation ◽  
Key Words Electrical Stimulation ◽  
Stimulation Of

The study involved 15 men with movement disorders of central origin. We used percutaneous electrical stimulation of the spinal cord with the application of electrodes in the projection of the lumbar thickening, proprioceptive stimulation, and their combination. The data obtained showed the effectiveness of the combined course of percutaneous electrical stimulation of the spinal cord and proprioceptive stimulation on changes in the excitability of spinal locomotor neural networks. Key words: electrical stimulation, spinal cord, proprioceptive stimulation, rehabilitation, motor neuron.

Effect of percutaneous electrical stimulation of the spinal cord on the manifestation of reciprocal and presynaptic inhibition α-motor neurons of the lower leg muscles against the background of a weak isometric contraction in magnitude

2021 ◽  
Author(s):  
D.A. Gladchenko ◽  
S.M. Bogdanov ◽  
L.V. Roshchina ◽  
A.A. Chelnokov
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Motor Neurons ◽  
Isometric Contraction ◽  
Presynaptic Inhibition ◽  
Plantar Flexion ◽  
Reciprocal Inhibition ◽  
Non Invasive ◽  
Leg Muscles ◽  
Stimulation Of

The article presents the results of a study of the reflex mechanisms of reciprocal and presynaptic inhibition at rest and when performing an isometric reduction of 5% of MPS against the background of twenty-minute non-invasive electrical stimulation of the spinal cord. It was found that at rest against the background of electrical stimulation, reciprocal and presynaptic inhibition was inverted to their relief, and when performing plantar flexion of the foot, on the contrary, reciprocal and presynaptic inhibition increased, but the severity of presynaptic inhibition was greater. Key words: percutaneous electrical stimulation of the spinal cord, reciprocal inhibition, presynaptic inhibition, isometric contraction.

scholarly journals Зв’язок активності висхідних шляхів із фазовим кодуванням у люмбальних відділах спинного мозку

2012 ◽  
Vol 3 (1) ◽  
pp. 140-145
Author(s):  
O. O. Shugurov
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Dorsal Column ◽  
Additional Information ◽  
Spinocerebellar Tract ◽  
Relationship Of ◽  
The Relationship ◽  
Stimulation Of

We studied the relationship of discharges phase characteristics in ascending column of spinal cord (SC) and specificity of activation of neurones, which generate negative components of evoked potentials of SC. The discharges was recorded from SC at a level of a presence of dorsal column (DC), spinocervical and dorsal spinocerebellar tract in upper lumbar and thoracic segments at a stimulation of a nerve or DC. It is shown, that the phase of the discharges depends on the quantity of synaptic delays in generating chain of such signals. Thus, the phase of a signal can carry the additional information on specificity of activation of the sensory elements in CNS.

scholarly journals Quantitative analysis of poliomyelitis-like paralysis in mice induced by a poliovirus replicon

2006 ◽  
Vol 87 (11) ◽  
pp. 3317-3327 ◽  
Author(s):  
Minetaro Arita ◽  
Noriyo Nagata ◽  
Tetsutaro Sata ◽  
Tatsuo Miyamura ◽  
Hiroyuki Shimizu
Keyword(s):  
Spinal Cord ◽  
Motor Neurons ◽  
Histological Analysis ◽  
Clinical Symptoms ◽  
Firefly Luciferase ◽  
Small Population ◽  
Post Inoculation ◽  
Spinal Cord Damage ◽  
The Relationship ◽  
Lumbar Cord

Poliovirus (PV) infection causes severe paralysis, typically of the legs, by destruction of the motor neurons in the spinal cord. In this study, the relationship between PV replication in the spinal cord, damage in the motor neurons and poliomyelitis-like paralysis was analysed in transgenic mice expressing the human PV receptor (TgPVR21). First, a PV replicon encoding firefly luciferase in place of the capsid genes (PV-Fluc mc) was trans-encapsidated in 293T cells and the trans-encapsidated PV-Fluc mc (TE-PV-Fluc mc) was then inoculated into the spinal cords of TgPVR21 mice. TE-PV-Fluc mc was recovered with a titre of 6.3×107 infectious units ml−1, which was comparable to those of PV1 strains. TgPVR21 mice inoculated with TE-PV-Fluc mc showed non-lethal paralysis of the hindlimbs, with severity ranging from a decline in grip strength to complete flaccid paralysis. The replication of TE-PV-Fluc mc in the spinal cord reached peak levels at 10 h post-inoculation (p.i.), followed by the appearance of paralysis at as early as 12 h p.i., reaching a plateau at 16 h p.i. Histological analysis showed a correlation between the lesion and the severity of the clinical symptoms in most mice. However, severe paralysis could also be observed with an apparently low lesion score, where as few as 5.3×102 motor neurons (1.4 % of the susceptible cells in the lumbar cord) were infected by TE-PV-Fluc mc. These results indicate that PV replication in a small population of the motor neurons was critical for severe residual poliomyelitis-like paralysis in TgPVR21 mice.

Effects of HBO with reduction of iNOS and HIF -1α in motor neurons after transient spinal cord ischemia in rabbits

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S452-S452
Author(s):  
Noritaka Murakami ◽  
Masahiro Sakurai ◽  
Takashi Horinouchi ◽  
Jun Ito ◽  
Shin Kurosawa ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Motor Neurons ◽  
Spinal Cord Ischemia
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