Electrical properties and morphology of motoneurons developing in dissociated unpurified co-culture of the embryonic rat brainstem, spinal cord, and hindlimb tissues

1998 ◽  
Vol 30 (4-5) ◽  
pp. 305-309 ◽  
Author(s):  
A. I. Ivanov ◽  
T. Launey ◽  
J. -P. Guéritaud ◽  
S. M. Korogod
Keyword(s):  
Spinal Cord ◽  
Electrical Properties ◽  
Rat Brainstem

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.

Binding sites for the glutamate-analogue [3H]AMPA in cultured rat brainstem and spinal cord

1983 ◽  
Vol 268 (1) ◽  
pp. 177-180 ◽  
Author(s):  
Elisabeth Hösli ◽  
P. Krogsgaard-Larsen ◽  
L. Hösli
Keyword(s):  
Spinal Cord ◽  
Binding Sites ◽  
Rat Brainstem

Cyanide modulates on the cervical activity in neonatal rat brainstem-spinal cord preparation

2011 ◽  
Vol 71 ◽  
pp. e317
Author(s):  
Mari Ito-Shiga ◽  
Nobuko Kanbara-Kume ◽  
Hideki Shimomura ◽  
Takakuni Tanizawa ◽  
Akiko Arata
Keyword(s):  
Spinal Cord ◽  
Neonatal Rat ◽  
Rat Brainstem

Electrical properties of frog motoneurons in the in situ spinal cord

1976 ◽  
Vol 39 (3) ◽  
pp. 459-473 ◽  
Author(s):  
P. C. Magherini ◽  
W. Precht
Keyword(s):  
Spinal Cord ◽  
Membrane Potential ◽  
Electrical Properties ◽  
Rana Temporaria ◽  
Reversal Potential ◽  
Input Resistance ◽  
Resting Potential ◽  
Equilibrium Potential ◽  
Spike Initiation

Electrical properties of the spinal motoneurons of Rana temporaria and R. esculenta were investigated in the in situ spinal cord at 20-22 degrees C by means of intracellular recording and current injection. Input resistance values depended on the method of measurement in a given cell but were generally inversely related to axon conduction velocity. The membrane-potential response to a subthreshold current pulse was composed of at least two exponentials with mean time constants of 2.5 and 20 ms. The membrance potential reached by the peak of a spike depended on the mode of spike initiation and membrane potential. Preceding a suprathreshold depolarization by a hyperpolarizing pulse could delay and eliminate spike initiation, similar to effects reported in certain invertebrate neurons. Antidromic invasion frequently failed in motoneurons of normal resting potential. Antidromic spike components (m,IS, SD) were similar to those of cat motoneurons. The delayed depolarization and the long afterhyperpolarization following an antidromic spike had many properties in common with the analogous afterpotentials of cat motoneurons. The reversal potential of the short afterhyperpolarization occurring immediately after the spike varied with resting potential and could not be used to determine potassium equilibrium potential. Sustained rhythmic firing could be evoked by continuous synaptic drive or long pulses of injected current. The plot of firing rate versus current strength had a substantial linear region. Both steady firing and adaptation properties varied markedly with motoneuron input resistance.

Changes in properties of lamprey reticulospinal neurons following spinal cord injury

2015 ◽  
Author(s):  
◽  
Timothee Pale
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Electrical Properties ◽  
Neurite Outgrowth ◽  
Axonal Transport ◽  
Axonal Regeneration ◽  
Retrograde Axonal Transport ◽  
Slight Reduction ◽  
Synaptic Inputs ◽  
Cord Injury

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] The lamprey is one of the most ancient vertebrates, sharing many of basic characteristics of the brain and spinal cord with higher, more evolved vertebrates such as mammals. However, unlike humans and other higher vertebrates, lampreys display robust axonal regeneration in the central nervous system following spinal cord injury (SCI). For instance, axons of reticulospinal (RS) neurons in the brain can regenerate and reconnect with spinal targets leading to recovery of locomotor behavior within a few weeks following SCI. During axonal regeneration, at [about]2-3 weeks following SCI, injured RS neurons display dramatic changes in their electrical properties (i.e. "injury phenotype", absence of 2/3 afterpotentials) compared to uninjured neurons. These changes may be due to axonal injury itself, interruption of retrograde axonal transport, and/or changes in synaptic inputs. The present work will focus on several aspects of lamprey RS neurons following SCI. (1) Can activation of second messenger signaling pathways stimulate neurite outgrowth of lamprey RS neurons without altering their electrical properties? (2) Does axotomy affect Ca2+ and SK channels and their underlying conductances? (3) Are the changes in biophysical properties of RS neurons following SCI due, in part, to disruption of retrograde axonal transport? (4) Does SCI lead to changes in morphology and synaptic inputs of injured lamprey RS neurons? For lamprey RS neurons in culture, activation of cAMP pathways stimulated neurite outgrowth. In brainspinal cord preparations, forskolin resulted in action potential broadening, at least for uninjured RS neurons, which would very likely increase calcium influx. In contrast, for lamprey RS neurons, dbcAMP stimulated neurite outgrowth without altering their electrical properties. These results suggest that activation of cAMP signaling may be an effective approach for stimulating axonal regeneration of RS neurons following spinal cord injury. Our results suggest that there may be little differences in Ca2+ currents and SK currents between injured and uninjured large RS neurons. Perhaps the slight reduction in the total Ca2+ influx combined with a slight reduction of SK current (fewer activated by Ca2+) is responsible for the abolishment of the sAHP in lamprey RS neurons [about]2-3 weeks following injury. In uninjured large RS neurons that were not physically damaged by the application of the microtubuledisrupting agent vinblastine, blocking retrograde axonal transport caused some neurons to fire erratically and display the "injury phenotype", which is typical for axotomized neurons following SCI. These results suggest that retrograde axonal transport may play an important role in the maintenance of normal electrical properties in uninjured lamprey large RS neurons. Additionally, these results suggest that following SCI, interruption of retrograde axonal transport perhaps contributes to the changes in electrical properties (i.e "injury phenotype") in injured lamprey RS neurons. Injured large RS neurons did not display significant differences in the amplitudes of their synaptic responses from stimulation of the oral hood compared to uninjured neurons whether they were stimulated contralaterally or ipsilaterally, and synaptic responses of injured and uninjured RS neurons from stimulations on either the right or the left side of the oral hood were not significantly different. Taken together, these results suggest that injury does not substantially alter the synaptic inputs of injured large RS neurons. Following rostral SCI in lampreys, large injured RS neurons did not display significant changes in their basic morphology of lamprey large RS neurons. For example, the major and minor diameters of injured large RS neurons were not significantly different than those of uninjured neurons. In addition, compared to uninjured neurons, injured neurons did not have different number of primary and secondary dendrites. These results suggest that SCI does not substantially alter the basic morphology of large lamprey RS neurons. The present work provided a better understanding of the mechanisms underlying the biophysical changes of injured lamprey RS neurons during axonal regeneration. These findings could help in the development of novel therapeutic strategies to enhance axonal regeneration, following spinal cord injury in higher vertebrates, including perhaps humans.

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