Advanced search

Is cortical excitability in rats altered after 1h of high frequency, Poisson distributed cortical stimulation?

Ine Buffel, Alfred Meurs (UGent) , Robrecht Raedt (UGent) , Veerle De Herdt (UGent) , RIEM EL TAHRY (UGent) , Bregt Van Nieuwenhuyse (UGent) , Lies Mollet (UGent) , Wytse Wadman (UGent) , Kristl Vonck (UGent) and Paul Boon (UGent)
Author
Organization
Abstract
Aims : Neurostimulation is a promising treatment for patients with refractory focal epilepsy who are not amenable to resective surgery. We have evaluated the effect of high-frequency cortical stimulation on cortical excitability in the motor cortex model (CSM). In the CSM, a ramp-shaped pulse train with increasing intensity is delivered to the motor cortex. The threshold intensity for eliciting forelimb clonus is determined through behavioural observation, and used as a measure for cortical excitability. Methods : Seven male Wistar rats were implanted with epidural electrodes over the motor cortex (AP-1mm; ML±3mm). All rats underwent 1h of sham stimulation, cortical stimulation (Poisson pulse, 130Hz, PW100µs) with an intensity of 10µA, or cortical stimulation at 100µA below the baseline threshold intensity on alternating days. The threshold intensity needed to elicit forelimb clonus was determined before (mean of 4measurements at 20min intervals) and immediately, 1h, 2h and 24h after stimulation. Results : Sham stimulation did not alter the threshold to forelimb clonus. Therapeutic stimulation with an intensity of 100µA lower than baseline threshold (mean intensity 205±22µA) significantly increased the threshold to forelimb clonus from 305±22µA (before) to 347±19 (immediately after), 339±23 (1h), 327±20 (2h) and 277±21µA (24h) after stimulation (p<0.001). When stimulated at 10µA, the threshold increased from 302±25µA to 319±15µA, 318±21µA, 319±18 µA, 321±32µA. Conclusion : High-frequency, Poisson-distributed cortical stimulation during 1h decreases cortical excitability at high intensities. This effect lasted 1h. Further studies are needed to determine whether this type of stimulation can become an effective alternative treatment for patients with focal neocortical epilepsy who are not amenable to surgery.
Keywords
Rats, Poisson-distributed stimulation, Epilepsy, cortical stimulation, cortical excitability

Citation

Please use this url to cite or link to this publication:

Chicago
Buffel, Ine, Alfred Meurs, Robrecht Raedt, Veerle De Herdt, RIEM EL TAHRY, Bregt Van Nieuwenhuyse, Lies Mollet, Wytse Wadman, Kristl Vonck, and Paul Boon. 2012. “Is Cortical Excitability in Rats Altered After 1h of High Frequency, Poisson Distributed Cortical Stimulation?” In Front. Hum. Neurosci. Conference Abstract : Belgian Brain Council.
APA
Buffel, I., Meurs, A., Raedt, R., De Herdt, V., EL TAHRY, R., Van Nieuwenhuyse, B., Mollet, L., et al. (2012). Is cortical excitability in rats altered after 1h of high frequency, Poisson distributed cortical stimulation? Front. Hum. Neurosci. Conference Abstract : Belgian Brain Council. Presented at the Belgian Brain Council 2012.
Vancouver
1.
Buffel I, Meurs A, Raedt R, De Herdt V, EL TAHRY R, Van Nieuwenhuyse B, et al. Is cortical excitability in rats altered after 1h of high frequency, Poisson distributed cortical stimulation? Front. Hum. Neurosci. Conference Abstract : Belgian Brain Council. 2012.
MLA
Buffel, Ine, Alfred Meurs, Robrecht Raedt, et al. “Is Cortical Excitability in Rats Altered After 1h of High Frequency, Poisson Distributed Cortical Stimulation?” Front. Hum. Neurosci. Conference Abstract : Belgian Brain Council. 2012. Print.
@inproceedings{5714118,
  abstract     = {Aims : Neurostimulation is a promising treatment for patients with refractory focal epilepsy who are not amenable to resective surgery. We have evaluated the effect of high-frequency cortical stimulation on cortical excitability in the motor cortex model (CSM). In the CSM, a ramp-shaped pulse train with increasing intensity is delivered to the motor cortex. The threshold intensity for eliciting forelimb clonus is determined through behavioural observation, and used as a measure for cortical excitability.
Methods : Seven male Wistar rats were implanted with epidural electrodes over the motor cortex (AP-1mm; ML{\textpm}3mm). All rats underwent 1h of sham stimulation, cortical stimulation (Poisson pulse, 130Hz, PW100{\textmu}s) with an intensity of 10{\textmu}A, or cortical stimulation at 100{\textmu}A below the baseline threshold intensity on alternating days. The threshold intensity needed to elicit forelimb clonus was determined before (mean of 4measurements at 20min intervals) and immediately, 1h, 2h and 24h after stimulation.
Results : Sham stimulation did not alter the threshold to forelimb clonus. Therapeutic stimulation with an intensity of 100{\textmu}A lower than baseline threshold (mean intensity 205{\textpm}22{\textmu}A) significantly increased the threshold to forelimb clonus from 305{\textpm}22{\textmu}A (before) to 347{\textpm}19 (immediately after), 339{\textpm}23 (1h), 327{\textpm}20 (2h) and 277{\textpm}21{\textmu}A (24h) after stimulation (p{\textlangle}0.001). When stimulated at 10{\textmu}A, the threshold increased from 302{\textpm}25{\textmu}A to 319{\textpm}15{\textmu}A, 318{\textpm}21{\textmu}A, 319{\textpm}18 {\textmu}A, 321{\textpm}32{\textmu}A.
Conclusion : High-frequency, Poisson-distributed cortical stimulation during 1h decreases cortical excitability at high intensities. This effect lasted 1h. Further studies are needed to determine whether this type of stimulation can become an effective alternative treatment for patients with focal neocortical epilepsy who are not amenable to surgery.},
  author       = {Buffel, Ine and Meurs, Alfred and Raedt, Robrecht and De Herdt, Veerle and EL TAHRY, RIEM and Van Nieuwenhuyse, Bregt and Mollet, Lies and Wadman, Wytse and Vonck, Kristl and Boon, Paul},
  booktitle    = {Front. Hum. Neurosci. Conference Abstract : Belgian Brain Council},
  keyword      = {Rats,Poisson-distributed stimulation,Epilepsy,cortical stimulation,cortical excitability},
  language     = {eng},
  location     = {Li{\`e}ge, Belgium},
  title        = {Is cortical excitability in rats altered after 1h of high frequency, Poisson distributed cortical stimulation?},
  url          = {http://dx.doi.org/10.3389/conf.fnhum.2012.210.00078},
  year         = {2012},
}

Altmetric
View in Altmetric