| Title |
Influence of (S)-ketamine on human motor cortex excitability
|
|---|---|
| Published in |
Experimental Brain Research, November 2012
|
| DOI | 10.1007/s00221-012-3347-6 |
| Pubmed ID | |
| Authors |
Oliver Höffken, Ida S. Haussleiter, Andrea Westermann, Jörn Lötsch, Christoph Maier, Martin Tegenthoff, Peter Schwenkreis |
| Abstract |
Previous studies demonstrated a reduction of motor cortical excitability through pharmacological NMDA receptor blockage. Interestingly, subanesthetic doses of racemic ketamine, a non-competitive NMDA receptor antagonist, had no effects on intracortical excitability evoked by transcranial magnetic stimulation. In this study, we aimed to substantiate these findings by using the more active enantiomer (S)-ketamine. (S)-ketamine has a threefold higher affinity for the NMDA receptor, but relatively little is known about its specific effects on human motor cortex excitability. Eleven healthy subjects (two female) participated in a randomized, double-blind, placebo-controlled cross-over study with four treatment conditions: either placebo or one of three subanesthetic doses of intravenous (S)-ketamine (serum target 10, 30 and 50 ng/ml, respectively). We assessed intracortical inhibition and facilitation using a paired-pulse TMS-paradigm. Resting motor threshold and cortical silent period were assessed as additional parameters. Solely at highest (S)-ketamine concentrations, intracortical inhibition was significantly reduced and intracortical facilitation strongly tended to be enhanced. In addition, we found a tendency to a prolonged silent period, while resting motor threshold was unaffected. We conclude that subanesthetic doses of (S)-ketamine show an enhancement on excitability in human motor cortex. Similar to findings using the racemic mixture of ketamine, the effect may be due to an increase in non-NMDA glutamatergic transmission which outweighs the NMDA receptor blockade. |
X Demographics
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Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 56 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 1 | 2% |
| Germany | 1 | 2% |
| Unknown | 54 | 96% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Professor | 7 | 13% |
| Student > Bachelor | 7 | 13% |
| Student > Doctoral Student | 6 | 11% |
| Student > Ph. D. Student | 5 | 9% |
| Researcher | 5 | 9% |
| Other | 12 | 21% |
| Unknown | 14 | 25% |
| Readers by discipline | Count | As % |
|---|---|---|
| Neuroscience | 11 | 20% |
| Medicine and Dentistry | 9 | 16% |
| Agricultural and Biological Sciences | 6 | 11% |
| Psychology | 5 | 9% |
| Nursing and Health Professions | 2 | 4% |
| Other | 6 | 11% |
| Unknown | 17 | 30% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 09 February 2013.
All research outputs
#18,329,207
of 22,696,971 outputs
Outputs from Experimental Brain Research
#2,472
of 3,218 outputs
Outputs of similar age
#214,692
of 276,615 outputs
Outputs of similar age from Experimental Brain Research
#27
of 37 outputs
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