Plasticity associated changes in cortical somatosensory evoked potentials following spinal cord injury in rats

Bazley, Faith A.; All, Angelo H.; Thakor, Nitish V.; Maybhate, Anil

doi:10.1109/iembs.2011.6090564

Cited by 15 publications

(16 citation statements)

References 21 publications

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“…The electrical stimulator gave a 2.82-Hz 0.1-ms square-shaped wave. Stimulus intensity was twice that of the motor threshold, which was determined by visible muscle contraction [Bazley, et al, 2011;Agrawal, et al, 2009;All et al, 2010].…”

Section: ) Somatosensory Evoked Potential (Ssep)mentioning

confidence: 99%

Machanism Associated with Apoptosis after Repetitive Transcranial Magnetic Stimulation in Permanent Stroke Rat Model

Jin¹,

Sohn²,

Jee³

2018

J Exp Stroke Transl Med

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Purpose: Neuromodulation therapy has been used as an adjunct treatment to promote motor recovery in stroke patients. The objectives of the present study were to determine the effect of repetitive transcranial magnetic stimulation (rTMS) on neurobehavioural recovery, evoked potential, and underlying biological mechanisms associated with neuronal cell death in rats after permanent middle cerebral artery occlusion. Methods:Our study included 10 control and 40 Sprague-Dawley (SD) rats; of them, 30 were successfully subjected to the induction of permanent middle cerebral artery occlusion (MCAO) stroke model (rTMS = 15, sham rTMS = 15). Ten-Hertz high-frequency rTMS was applied to the ipsilesional forepaw motor cortex for 2 weeks in the rTMS group. The somatosensory-evoked potential (SSEP) and motorevoked potential (MEP) were used to evaluate the electrophysiological changes. The behavioural function of the stroke rats was evaluated using the rotarod and Garcia tests. Stroke area was measured using a histological staining technique. Immunoblotting was used to explore the mechanisms of rTMS associated with neuronal apoptosis.Results: 10 control and 20 MCAO rats (NrTMS = 10; Nsham = 10) completed the experimental course. Regarding MEP amplitude, repeated-measured analysis of variance (RMANOVA) showed a significant TIME effect [F (2, 0.106) = 11.241, P < 0.001] and TIME × INTERVENTION interaction [F (2, 0.057) = 6.053, P = 0.005] on MEP amplitude, suggesting the beneficial effect of rTMS on motor cortical excitability. Regarding peak to peak SSEP amplitude, RMANOVA showed a significant TIME effect [F (2, 4.920) = 3.4551, P = 0.042]. In terms of latency to fall, RMANOVA identified a significant TIME effect [F (7, 16640.335) = 24.425, P < 0.001] and INTERVENTION × TIME interaction [F (7, 2348.295) = 3.447, P = 0.002]. In terms of distance to fall, RMANOVA revealed a TIME effect [F (7, 101.679) = 26.515, P < 0.001] and INTERVENTION × TIME interaction [F (7, 13.607) = 3.548, P < 0.002]. In terms of Garcia score, RMANOVA revealed a significant effect of TIME [F (7, 69.282) = 153.689, P < 0.05] and INTERVENTION × TIME interaction [F (7, 2.282) = 5.063, P < 0.05], suggesting a beneficial effect of rTMS over sham treatment. In the Kruskal-Wallis test of endoplasmic reticulum (ER) stress protein, rTMS also inhibited the protein levels of glucose-regulated protein 78 (GRP78), CATT/EBP homologous protein (CHOP), and p-eukaryotic initiation factor 2α (eIF2α).Conclusion: 10-Hertz rTMS leads to a rapid recovery in behavioural performance after permanent MCAO stroke model and maintains increased ipsilesional motor cortex activity 2 weeks after rTMS. The underlying beneficial effects of rTMS may be associated with ER stress protein in the neuronal cell death pathway.

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Section: ) Somatosensory Evoked Potential (Ssep)mentioning

confidence: 99%

Machanism Associated with Apoptosis after Repetitive Transcranial Magnetic Stimulation in Permanent Stroke Rat Model

Jin¹,

Sohn²,

Jee³

2018

J Exp Stroke Transl Med

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“…Rewarming to 37°C was gradual and *1°C every 5 minutes for 30 minutes. A 5-cm rectal probe was used to monitor the core temperature, and rats were placed on a heating pad to maintain their body temperatures at 37°C -0.5°C throughout the experiments (Agrawal et al, 2009(Agrawal et al, , 2010a(Agrawal et al, , 2010bBazley et al, 2011;Bazley et al, 2012Bazley et al, , 2013Bazley et al, , 2014aYenari and Hans, 2012) (Fig. 1).…”

Section: Local Hypothermia Inductionmentioning

confidence: 99%

“…In total, *150 sweeps were recorded per limb per electrode. The neuroelectrophysiology monitoring setup (Tucker-Davis Technology) was used for multilimb acquisition of SSEPs as previously described (Agrawal et al, 2010b;Bazley et al, 2011;Maybhate et al, 2012). Upon each stimulation, SSEP signals were recorded simultaneously from all four cortical screw electrodes using the amplifier and data acquisition setup.…”

Section: Electrophysiological Monitoringmentioning

confidence: 99%

Prolonged Local Hypothermia Has No Long-Term Adverse Effect on the Spinal Cord

Vipin

Kortelainen

Al‐Nashash

et al. 2015

Therapeutic Hypothermia and Temperature Management

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Hypothermia is known to be neuroprotective and is one of the most effective and promising first-line treatments for central nervous system (CNS) trauma. At present, induction of local hypothermia, as opposed to general hypothermia, is more desired because of its ease of application and safety; fewer side effects and an absence of severe complications have been noted. Local hypothermia involves temperature reduction of a small and specific segment of the spinal cord. Our group has previously shown the neuroprotective effect of short-term, acute moderate general hypothermia through improvements in electrophysiological and motor behavioral assessments, as well as histological examination following contusive spinal cord injury (SCI) in rats. We have also shown the benefit of using short-term local hypothermia versus short-term general hypothermia post-acute SCI. The overall neuroprotective benefit of hypothermia can be categorized into three main components: (1) induction modality, general versus local, (2) invasive, semi-invasive or noninvasive, and (3) duration of hypothermia induction. In this study, a series of experiments were designed to investigate the feasibility, long-term safety, as well as eventual complications and side effects of prolonged, semi-invasive, moderate local hypothermia (30°C±0.5°C for 5 and 8 hours) in rats with uninjured spinal cord while maintaining their core temperature at 37°C±0.5°C. The weekly somatosensory evoked potential and motor behavioral (Basso, Beattie and Bresnahan) assessments of rats that underwent 5 and 8 hours of semi-invasive local hypothermia, which revealed no statistically significant changes in electrical conductivity and behavioral outcomes. In addition, 4 weeks after local hypothermia induction, histological examination showed no anatomical damages or morphological changes in their spinal cord structure and parenchyma. We concluded that this method of prolonged local hypothermia is feasible, safe, and has the potential for clinical translation.

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“…Our SCI model has been previously described (Agrawal et al, 2008(Agrawal et al, , 2010a(Agrawal et al, , 2010bAl-Nashash et al, 2009;All et al, 2009All et al, , 2010All et al, , 2012Iyer et al, 2010;Kerr et al, 2010;Bazley et al, 2011Bazley et al, , 2012aBazley et al, , 2012b. A laminectomy was performed by removing the T8 thoracic vertebra to expose the dorsal surface of the spinal cord without opening the dura mater.…”

Section: Laminectomy and Contusion Injurymentioning

confidence: 99%

The Effects of Local and General Hypothermia on Temperature Profiles of the Central Nervous System Following Spinal Cord Injury in Rats

Bazley

Pashai²,

Kerr

et al. 2014

Therapeutic Hypothermia and Temperature Management

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Local and general hypothermia are used to treat spinal cord injury (SCI), as well as other neurological traumas. While hypothermia is known to provide significant therapeutic benefits due to its neuroprotective nature, it is unclear how the treatment may affect healthy tissues or whether it may cause undesired temperature changes in areas of the body that are not the targets of treatment. We performed 2-hour moderate general hypothermia (32°C core) or local hypothermia (30°C spinal cord) on rats that had received either a moderate contusive SCI or laminectomy (control) while monitoring temperatures at three sites: the core, spinal cord, and cortex. First, we identified that injured rats that received general hypothermia exhibited larger temperature drops at the spinal cord (-3.65°C, 95% confidence intervals [CIs] -3.72, -3.58) and cortex ( -3.64°C, CIs -3.73, -3.55) than uninjured rats (spinal cord: -3.17°C, CIs -3.24, -3.10; cortex: -3.26°C, CIs -3.34, -3.17). This was found due to elevated baseline temperatures in the injured group, which could be due to inflammation. Second, both general hypothermia and local hypothermia caused a significant reduction in the cortical temperature (-3.64°C and -1.18°C, respectively), although local hypothermia caused a significantly lower drop in cortical temperature than general hypothermia ( p < 0.001). Lastly, the rates of rewarming of the cord were not significantly different among the methods or injury groups that were tested; the mean rate of rewarming was 0.13 -0.1°C/ min. In conclusion, local hypothermia may be more suitable for longer durations of hypothermia treatment for SCI to reduce temperature changes in healthy tissues, including the cortex.

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Plasticity associated changes in cortical somatosensory evoked potentials following spinal cord injury in rats

Cited by 15 publications

References 21 publications

Machanism Associated with Apoptosis after Repetitive Transcranial Magnetic Stimulation in Permanent Stroke Rat Model

Machanism Associated with Apoptosis after Repetitive Transcranial Magnetic Stimulation in Permanent Stroke Rat Model

Prolonged Local Hypothermia Has No Long-Term Adverse Effect on the Spinal Cord

The Effects of Local and General Hypothermia on Temperature Profiles of the Central Nervous System Following Spinal Cord Injury in Rats

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