Influences of spinal cord temperature changes on reflex discharge and spontaneous activity of spinal motoneurones in pigeons and leguans

1980 ◽  
Vol 139 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Klaus G�rke
Keyword(s):  
Spinal Cord ◽  
Spontaneous Activity ◽  
Temperature Changes ◽  
Spinal Cord Temperature ◽  
Reflex Discharge ◽  
Spinal Motoneurones

scholarly journals A supervised machine learning approach to characterize spinal network function

2019 ◽  
Vol 121 (6) ◽  
pp. 2001-2012 ◽  
Author(s):  
A. N. Dalrymple ◽  
S. A. Sharples ◽  
N. Osachoff ◽  
A. P. Lognon ◽  
P. J. Whelan
Keyword(s):  
Machine Learning ◽  
Spinal Cord ◽  
Nervous System ◽  
Spontaneous Activity ◽  
Machine Learning Algorithms ◽  
Supervised Machine Learning ◽  
Network Activity ◽  
Multilayer Perceptrons ◽  
Network Development ◽  
Newborn Mice

Spontaneous activity is a common feature of immature neuronal networks throughout the central nervous system and plays an important role in network development and consolidation. In postnatal rodents, spontaneous activity in the spinal cord exhibits complex, stochastic patterns that have historically proven challenging to characterize. We developed a software tool for quickly and automatically characterizing and classifying episodes of spontaneous activity generated from developing spinal networks. We recorded spontaneous activity from in vitro lumbar ventral roots of 16 neonatal [postnatal day (P)0–P3] mice. Recordings were DC coupled and detrended, and episodes were separated for analysis. Amplitude-, duration-, and frequency-related features were extracted from each episode and organized into five classes. Paired classes and features were used to train and test supervised machine learning algorithms. Multilayer perceptrons were used to classify episodes as rhythmic or multiburst. We increased network excitability with potassium chloride and tested the utility of the tool to detect changes in features and episode class. We also demonstrate usability by having a novel experimenter use the program to classify episodes collected at a later time point (P5). Supervised machine learning-based classification of episodes accounted for changes that traditional approaches cannot detect. Our tool, named SpontaneousClassification, advances the detail in which we can study not only developing spinal networks, but also spontaneous networks in other areas of the nervous system.NEW & NOTEWORTHY Spontaneous activity is important for nervous system network development and consolidation. Our software uses machine learning to automatically and quickly characterize and classify episodes of spontaneous activity in the spinal cord of newborn mice. It detected changes in network activity following KCl-enhanced excitation. Using our software to classify spontaneous activity throughout development, in pathological models, or with neuromodulation, may offer insight into the development and organization of spinal circuits.

scholarly journals Glycine Release from Radial Cells Modulates the Spontaneous Activity and Its Propagation during Early Spinal Cord Development

2010 ◽  
Vol 30 (1) ◽  
pp. 390-403 ◽  
Author(s):  
A.-L. Scain ◽  
H. Le Corronc ◽  
A.-E. Allain ◽  
E. Muller ◽  
J.-M. Rigo ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spontaneous Activity ◽  
Spinal Cord Development ◽  
Glycine Release

scholarly journals INPUT-OUTPUT RELATION IN A FLEXOR REFLEX

1957 ◽  
Vol 41 (2) ◽  
pp. 297-306 ◽  
Author(s):  
David P. C. Lloyd
Keyword(s):  
Spinal Cord ◽  
Afferent Input ◽  
Surprising Result ◽  
Input Output ◽  
Flexor Reflex ◽  
Afferent Fibers ◽  
Closed Chain ◽  
Central Paths ◽  
Reflex Threshold ◽  
Reflex Discharge

Observations have been made upon a typical flexor reflex with the aim of disclosing the changes in amount, latency, and temporal configuration of reflex discharge that take place as afferent input is varied from zero to maximal for the band of cutaneous myelinated afferent fibers that extends upward from approximately 6 µ in diameter (group II fibers). Reflex threshold is reached at 6 to 12 per cent maximal afferent input. From threshold to maximal input the relation between input and amount of output is essentially linear, latency on the average decreases, the shorter central paths in general gain preference, but the known minimum pathway, one of three neurons, does not transmit unless aided by convergent activity. Flexor reflex discharge may occur in several bursts suggesting the existence of closed chain connections in the internuncial pools of the spinal cord. At any given input there is, in successively elicited reflexes, little correlation between latency and amount of discharge, at first sight a surprising result for each variable can be taken as a measure of excitability status of the motoneuron population. However, latency of discharge indicates excitability at the beginning of the reflex event whereas amount of discharge is an expression of excitability over the entire period of discharge. Given a constantly and rapidly fluctuating excitability absence of correlation between these variables would be an anticipated result.

scholarly journals Modulation of motoneurone excitability during rhythmic motor outputs

2018 ◽  
Vol 43 (11) ◽  
pp. 1176-1185 ◽  
Author(s):  
Kevin E. Power ◽  
Evan J. Lockyer ◽  
Davis A. Forman ◽  
Duane C. Button
Keyword(s):  
Spinal Cord ◽  
Electrical Properties ◽  
Central Pattern Generators ◽  
Indirect Evidence ◽  
Rhythmic Motor ◽  
Current State ◽  
Motor Outputs ◽  
Descending Input ◽  
Pattern Generators ◽  
Spinal Motoneurones

In quadrupeds, special circuity located within the spinal cord, referred to as central pattern generators (CPGs), is capable of producing complex patterns of activity such as locomotion in the absence of descending input. During these motor outputs, the electrical properties of spinal motoneurones are modulated such that the motoneurone is more easily activated. Indirect evidence suggests that like quadrupeds, humans also have spinally located CPGs capable of producing locomotor outputs, albeit descending input is considered to be of greater importance. Whether motoneurone properties are reconfigured in a similar manner to those of quadrupeds is unclear. The purpose of this review is to summarize our current state of knowledge regarding the modulation of motoneurone excitability during CPG-mediated motor outputs using animal models. This will be followed by more recent work initially aimed at understanding changes in motoneurone excitability during CPG-mediated motor outputs in humans, which quickly expanded to also include supraspinal excitability.

Exercise-Induced Temperature Changes in the Tympanic Membrane and Skin of Patients with Spinal Cord Injury

1994 ◽  
pp. 77-83 ◽  
Author(s):  
Kojiro Ishii ◽  
Masahiro Yamasaki ◽  
Satoshi Muraki ◽  
Takashi Komura ◽  
Kunio Kikuchi ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Tympanic Membrane ◽  
Temperature Changes ◽  
Cord Injury ◽  
Exercise Induced

Midbrain neuronal responses to local and spinal cord temperatures

1976 ◽  
Vol 231 (5) ◽  
pp. 1573-1578 ◽  
Author(s):  
T Hori ◽  
Y Harada
Keyword(s):  
Spinal Cord ◽  
Firing Rate ◽  
Reticular Formation ◽  
Single Unit ◽  
Neuronal Responses ◽  
Heating And Cooling ◽  
Midbrain Reticular Formation ◽  
Spinal Cord Temperature ◽  
Temperature Signal ◽  
Cold Sensitive

Water-perfused thermodes were implanted over the lumbothoracic spinal cord and unilaterally in the midbrain of urethan-anesthetized rabbits. Single-unit activities were recorded with steel microelectrodes from the thermosensitive neurons in the midbrain reticular formation (MRF), and the effects of heating and cooling of the spinal cord were studied. Of 38 cold-sensitive MRF neurons studied, 7 units decreased their firing rate upon elevation of spinal cord temperature (Tsc) and 3 units showed the opposite type of response to Tsc. The remaining 28 cold units were not affected by the changes in Tsc between 30 and 43 degrees C. Of 17 warm units, 3 units increased and one unit decreased the firing rate during spinal cord heating. These results suggest that the temperature signal arising from thermosensitive structures in the spinal cord may be transmitted to some of the locally thermosensitive neurons in the MRF.

Effect of spinal cord temperature on carotid blood flow in the Pekin duck

1980 ◽  
Vol 385 (3) ◽  
pp. 269-271 ◽  
Author(s):  
C. Bech ◽  
W. Rautenberg ◽  
B. May ◽  
K. Johansen
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Pekin Duck ◽  
Carotid Blood Flow ◽  
Spinal Cord Temperature

Changes in Properties of Spinal Dorsal Horn Neurons and Their Sensitivity to Morphine after Spinal Cord Injury in the Rat

2005 ◽  
Vol 102 (1) ◽  
pp. 152-164 ◽  
Author(s):  
Jungang Wang ◽  
Mikito Kawamata ◽  
Akiyoshi Namiki
Keyword(s):  
Spinal Cord ◽  
Spontaneous Activity ◽  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
High Threshold ◽  
Dorsal Horn Neurons ◽  
Spinal Dorsal ◽  
Cord Injury ◽  
Spinal Dorsal Horn Neurons ◽  
Wdr Neurons

Background To gain a better understanding of spinal cord injury (SCI)-induced central neuropathic pain, the authors investigated changes in properties of spinal dorsal horn neurons located rostrally and caudally to the lesion and their sensitivity to morphine in rats after SCI. Methods The right spinal cord of Sprague-Dawley rats was hemisected at the level of L2. At 10 to 14 days after the SCI, when mechanical hyperalgesia/allodynia had fully developed, spontaneous activity and evoked responses to mechanical stimuli of wide-dynamic-range (WDR) and high-threshold neurons rostral and caudal to the lesion were recorded. Effects of cumulative doses of systemic (0.1-3 mg/kg) and spinal (0.1-5 microg) administration of morphine on spontaneous activity and evoked responses to the stimuli of the neurons were evaluated. Results Spontaneous activity significantly increased in WDR neurons both rostral and caudal to the SCI site, but high-frequency background discharges with burst patterns were only observed in neurons rostral to the SCI site. Significant increases in responses to the mechanical stimuli were seen both in WDR and high-threshold neurons located both rostrally and caudally to the lesion. The responses to nonnoxious and noxious stimuli were significantly greater in caudal WDR neurons than in rostral WDR neurons. In contrast, the responses to pinch stimuli were significantly higher in rostral high-threshold neurons than those in caudal high-threshold neurons. Systemically administered morphine had a greater effect on responses to nonnoxious and noxious stimuli of rostral WDR neurons than those of caudal WDR neurons. Spinally administered morphine significantly suppressed responses of WDR neurons in SCI animals to nonnoxious stimuli compared with those in sham-operated control animals. Conclusions The findings suggest that changes in properties of spinal dorsal horn neurons after SCI are caused by different mechanisms, depending on the classification of the neurons and their segmental locations.

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