Journal of neuroscience methods
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J. Neurosci. Methods · Dec 2015
Randomized Controlled TrialDemarcation of secondary hyperalgesia zones: Punctate stimulation pressure matters.
Secondary hyperalgesia is increased sensitivity in normal tissue near an injury, and it is a measure of central sensitization reflecting injury-related effects on the CNS. Secondary hyperalgesia areas (SHAs), usually assessed by polyamide monofilaments, are important outcomes in studies of analgesic drug effects in humans. However, since the methods applied in demarcating the secondary hyperalgesia zone seem inconsistent across studies, we examined the effect of a standardized approach upon the measurement of SHA following a first degree burn injury (BI). ⋯ This is the first study to demonstrate that demarcation of secondary hyperalgesia zones depends on the developed pressure of the punctate stimulator used.
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J. Neurosci. Methods · Nov 2015
Combining micro-computed tomography with histology to analyze biomedical implants for peripheral nerve repair.
Biomedical implants used in tissue engineering repairs, such as scaffolds to repair peripheral nerves, can be too large to examine completely with histological analyses. Micro-computed tomography (micro-CT) with contrast agents allows ex vivo visualization of entire biomaterial implants and their interactions with tissues, but contrast agents can interfere with histological analyses of the tissues or cause shrinkage or loss of antigenicity. ⋯ Because this combination of treatments is rapid and does not alter tissue morphology, this expands the ex vivo methods available to examine the success of biomaterial implants used for tissue engineering repairs.
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J. Neurosci. Methods · Nov 2015
Transdermal spinal catheter placement in piglets: Description and validation of the technique.
The swine species represents a perfect model for translational medicine due to its physiological and anatomical resemblance to humans. The development of techniques for spinal catheter insertion in swine is significantly useful but, at the moment, the only technique described requires laminectomy as a surgical approach. ⋯ In conclusion, the technique can be performed safely in piglets, and provides an easier and less invasive approach for spinal catheter insertion.
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J. Neurosci. Methods · Oct 2015
An unexpected target of spinal direct current stimulation: Interhemispheric connectivity in humans.
Transcutaneous spinal Direct Current Stimulation (tsDCS) is a noninvasive technique based on the application of weak electrical currents over spinal cord. ⋯ tsDCS modulates interhemispheric processing in a polarity-specific manner, with anodal stimulation leading to a functional disconnection between hemispheres. tsDCS would be a new promising therapeutic tool in managing a number of human diseases characterized by an impaired interhemispheric balance, or an early rehabilitation strategy in patients with acute brain lesions, when other non-invasive brain stimulation techniques (NIBS) are not indicated due to safety concerns.
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To date, the blood oxygenated-level dependent (BOLD) functional magnetic resonance imaging (fMRI) technique has enabled an objective and deeper understanding of pain processing mechanisms embedded within the human central nervous system (CNS). In order to further comprehend the benefits and limitations of BOLD fMRI in the context of pain as well as the corresponding subjective pain ratings, we evaluated the univariate response, test-retest reliability and confidence intervals (CIs) at the 95% level of both data types collected during evoked stimulation of 40°C (non-noxious), 44°C (mildly noxious) and a subject-specific temperature eliciting a 7/10 pain rating. ⋯ Test-retest reliability was observed to be highest for VAS pain ratings obtained during the 7/10 pain stimulation (ICC=0.938), while ICC values of pain fMRI data for a distribution of CNS structures ranged from 0.5 to 0.859 (p<0.05). Importantly, the upper and lower confidence interval CI bounds reported herein could be utilized in subsequent trials involving healthy volunteers to hypothesize the magnitude of effect required to overcome inherent variability of either VAS pain ratings or BOLD responses evoked during innocuous or noxious thermal stimulation.