scholarly journals Motor axon excitability measures in the rat tail are the same awake or anaesthetized using sodium pentobarbital

2019 ◽  
Author(s):  
Kelvin E Jones ◽  
David J Bennett
Keyword(s):  
Female Rats ◽  
Sodium Pentobarbital ◽  
Test Results ◽  
Bonferroni Correction ◽  
Motor Axons ◽  
Nerve Excitability ◽  
Cord Injury ◽  
Discrete Measures ◽  
Awake Condition ◽  
Rat Tail

AbstractBackgroundNerve excitability tests in sciatic motor axons are sensitive to anaesthetic choice. Results using ketamine/xylazine (KX) are different from those using sodium pentobarbital (SP). It is not clear which results are most similar to the awake condition, though results using SP appear more similar to human results.MethodsNerve excitability in tail motor axons was tested in 8 adult female rats with a chronic sacral spinal cord injury. These animals have no behavioural response to electrical stimulation of the tail and were tested awake and then anaesthetized using SP.ResultsThe nerve excitability test results in the awake condition were indistinguishable from the results when the same rats were anaesthetized with sodium pentobarbital. Summary plots of the test results overlap within the boundaries of the standard error and paired t-tests on the 42 discrete measures generated by nerve excitability testing yielded no significant differences (after Bonferroni correction for multiple comparisons).ConclusionsNerve excitability test results in rat motor axons are the same whether the animals are awake or anesthetized using sodium pentobarbital.

scholarly journals Nerve Excitability Differences in Slow and Fast Motor Axons of the Rat: more than just Ih

2019 ◽  
Author(s):  
James M. Bell ◽  
Chad Lorenz ◽  
Kelvin E. Jones
Keyword(s):  
Sodium Pentobarbital ◽  
Motor Axons ◽  
Recovery Cycle ◽  
Cation Current ◽  
Nerve Excitability ◽  
Peripheral Nerve Excitability ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Inwardly Rectifying ◽  
Threshold Electrotonus

AbstractObjectiveThe objective was to determine if choice of anaesthetic confounded previous conclusions about the differences in nerve excitability indices between fast and slow motor axons.MethodologyNerve excitability of the rat sciatic nerve was tested while measuring responses of motor axons innervating the slow-twitch soleus (SOL) and fast-twitch tibialis anterior (TA) muscles. The experiments were conducted with sodium pentobarbital (SP) anaesthetic and compared to previous results that used ketamine-xylazine (KX).Results and ConclusionsPrevious conclusions about the differences in nerve excitability indices between TA and SOL motor axons using KX were corroborated and extended when experiments were done with SP. Nerve excitability indices sensitive to changes in hyperpolarization-activated inwardly rectifying cation current (Ih) indicated an increase in Ih in SOL axons compared to TA axons (e.g. S3 (−100 %), t=7.949 (df=10), p < 0.0001; TEh (90–100 ms), t=2.659 (df=20), p = 0.0145; hyperpolarizing I/V slope, t=4.308 (df=19), p = 0.0004). SOL axons also had a longer strength-duration time constant (t=3.35 (df=20), p = 0.0032) and a longer and larger magnitude relative refractory period (RRP (ms) t=3.53 (df=12), p = 0.0041; Refractoriness at 2 ms t=0.0055 (df=9), p = 0.0055).Anaesthetic choice affected many measures of peripheral nerve excitability with differences most apparent in tests of threshold electrotonus and recovery cycle. For example, recovery cycle with KX lacked a clear superexcitable and late subexcitable period. We conclude that KX had a confounding effect on nerve excitability results consistent with ischaemic depolarization. Results using SP revealed the full extent of differences in nerve excitability measures between putative slow and fast motor axons of the rat. These differences have important implications for the use of nerve excitability measures during processes such as ageing where it is believed that there is a selective loss of fast axons.New & NoteworthyNerve excitability testing is a tool used to provide insight into the properties of ion channels in peripheral nerves. It is used clinically to assess pathophysiology of motor axons. Researchers customarily think of motor axons as homogeneous; however, we demonstrate there are clear differences between fast and slow axons in the rat. This is important for interpreting results with selective motor neuronopathy, like aging where fast axons are at high risk of degeneration.

Plasticity of lower limb motor axons after cervical cord injury

2009 ◽  
Vol 120 (1) ◽  
pp. 204-209 ◽  
Author(s):  
Robert A. Boland ◽  
Hugh Bostock ◽  
Matthew C. Kiernan
Keyword(s):  
Lower Limb ◽  
Cervical Cord ◽  
Motor Axons ◽  
Cord Injury ◽  
Cervical Cord Injury

The neuroprotective role of morroniside against spinal cord injury in female rats

2021 ◽  
pp. 105105
Author(s):  
Fei-Xiang Duan ◽  
Yu-Jiao Shi ◽  
Jing Chen ◽  
Xue Song ◽  
Lin Shen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Female Rats ◽  
Cord Injury

scholarly journals Exendin-4 Plays a Protective Role in a Rat Model of Spinal Cord Injury Through SERCA2

2018 ◽  
Vol 47 (2) ◽  
pp. 617-629 ◽  
Author(s):  
Zhonglei Sun ◽  
Yingfu Liu ◽  
Xianbin Kong ◽  
Renjie Wang ◽  
Yunqiang Xu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Rat Model ◽  
Rating Scale ◽  
Protective Role ◽  
Female Rats ◽  
Spinal Cord Tissue ◽  
Cord Injury ◽  
Glucagon Like Peptide 1 ◽  
Long Acting

Background/Aims: Current therapies for spinal cord injury (SCI) have limited efficacy, and identifying a therapeutic target is a pressing need. Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2 (SERCA2) plays an important role in regulating calcium homeostasis, which has been shown to inhibit apoptosis. Exendin-4 has been shown to inhibit the apoptosis of nerve cells in SCI, which can also improve SERCA2 expression. In this study, we sought to determine whether exendin-4 plays a protective role in a rat model of SCI via SERCA2. Methods: To investigate the effects of exendin-4 on SCI, a rat model of SCI was induced by a modified version of Allen’s method. Spinal cord tissue sections from rats and western blot analysis were used to examine SERCA2 expression after treatment with the long-acting glucagon-like peptide 1 receptor exendin-4 or the SERCA2 antagonist 5(6)-carboxyfluorescein diacetate N-succinimidyl ester (CE). Locomotor function was evaluated using the Basso Beattie Bresnahan locomotor rating scale and slanting board test. Results: Cell apoptosis was increased with CE treatment and decreased with exendin-4 treatment. Upregulation of SERCA2 in female rats with SCI resulted in an improvement of motor function scores and histological changes. Conclusion: These findings suggest that exendin-4 plays a protective role in a rat model of SCI through SERCA2 via inhibition of apoptosis. Existing drugs targeting SERCA2 may be an effective therapeutic strategy for the treatment of SCI.

Activation of the external urethral sphincter central pattern generator by a 5-HT1A receptor agonist in rats with chronic spinal cord injury

2007 ◽  
Vol 292 (4) ◽  
pp. R1699-R1706 ◽  
Author(s):  
Paul C. Dolber ◽  
Baojun Gu ◽  
Xiaoyang Zhang ◽  
Matthew O. Fraser ◽  
Karl B. Thor ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Receptor Agonist ◽  
Bladder Capacity ◽  
Female Rats ◽  
Residual Volume ◽  
Urethral Sphincter ◽  
External Urethral Sphincter ◽  
Chronic Spinal Cord Injury ◽  
Cord Injury

We recently demonstrated that treatment with the 5-HT1A/7 receptor agonist [(R)-(+)-8-hydroxy-2-di-n-propylamino]tetralin (8-OH-DPAT) increases bladder capacity in chloralose-anesthetized female cats with chronic spinal cord injury. In the current study, we investigated the effects of 8-OH-DPAT on bladder capacity and external urethral sphincter (EUS) activity in urethane-anesthetized female rats (initial body mass 175–200 g) with chronic spinal cord injury (transsection at T10). Cystometric study took place 8–12 wk posttranssection. Intravesical pressure was monitored in urethane-anesthetized rats with a transvesical catheter, and EUS activity was assessed electromyographically. Spinal cord injury disrupts phasic activity of the EUS, resulting in decreased voiding efficiency and increased residual volume. 8-OH-DPAT induced a dose-dependent decrease in bladder capacity (the opposite of its effect in chronic spinal cord-injured cats) with an increase in micturition volume and decrease in residual volume resulting from improvement in voiding efficiency. The unexpected improvement in voiding efficiency can be explained by the 8-OH-DPAT-induced emergence of phasic EUS relaxation. Phasic EUS relaxation was also altered by 8-OH-DPAT in spinally intact rats, whereas the 5-HT1A receptor antagonist N-tert-butyl-3-[4-(2-methoxyphenyl)-piperazin-1-yl]-2-phenylpropanamide (WAY-100635), on its own, was without effect. It remains to be determined when phasic relaxation is restored after spinal cord injury, and indeed whether it is ever truly lost or is only temporarily separated from excitatory input.

Nerve excitability changes of motor axons in Fabry disease suggest an ischaemic component to nerve dysfunction

2007 ◽  
Vol 118 (5) ◽  
pp. e155
Author(s):  
S.V. Tan ◽  
P. Lee ◽  
R.J.L. Walters ◽  
A. Mehta ◽  
H. Bostock
Keyword(s):  
Fabry Disease ◽  
Motor Axons ◽  
Nerve Excitability ◽  
Nerve Dysfunction

scholarly journals Energy Cost of Propulsion in Standard and Ultralight Wheelchairs in People With Spinal Cord Injuries

1999 ◽  
Vol 79 (2) ◽  
pp. 146-158 ◽  
Author(s):  
Claire E Beekman ◽  
Leslie Miller-Porter ◽  
Marion Schoneberger
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Energy Cost ◽  
Spinal Cord Injuries ◽  
Oxygen Cost ◽  
Wheelchair Propulsion ◽  
Bonferroni Correction ◽  
Related Factors ◽  
Cord Injury ◽  
Different Levels

AbstractBackground and Purpose. Wheelchair- and subject-related factors influence the efficiency of wheelchair propulsion. The purpose of this study was to compare wheelchair propulsion in ultralight and standard wheelchairs in people with different levels of spinal cord injury. Subjects. Seventy-four subjects (mean age=26.2 years, SD=7.14, range=17-50) with spinal cord injury resulting in motor loss (30 with tetraplegia and 44 with paraplegia) were studied. Method. Each subject propelled standard and ultralight wheelchairs around an outdoor track at self-selected speeds, while data were collected at 4 predetermined intervals. Speed, distance traveled, and oxygen cost (V̇o2 mL/kg/m) were compared by wheelchair, group, and over time, using a Bonferroni correction. Results. In the ultralight wheelchair, speed and distance traveled were greater for both subjects with paraplegia and subjects with tetraplegia, whereas V̇o2 was less only for subjects with paraplegia. Subjects with paraplegia propelled faster and farther than did subjects with tetraplegia. Conclusion and Discussion. The ultralight wheelchair improved the efficiency of propulsion in the tested subjects. Subjects with tetraplegia, especially at the C6 level, are limited in their ability to propel a wheelchair.

Differences in nerve excitability properties across upper limb sensory and motor axons

2021 ◽  
Author(s):  
Antonia S. Carroll ◽  
James Howells ◽  
Cindy S.Y. Lin ◽  
Susanna B. Park ◽  
Neil Simon ◽  
...  
Keyword(s):  
Upper Limb ◽  
Motor Axons ◽  
Nerve Excitability
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