Journal of neuroscience methods
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J. Neurosci. Methods · Mar 2009
New method for quantification and statistical analysis of nociceptive reflex receptive fields in humans.
A method for quantifying nociceptive withdrawal reflex receptive fields in human volunteers and patients is described. The reflex receptive field (RRF) for a specific muscle denotes the cutaneous area from which a muscle contraction can be evoked by a nociceptive stimulus. The method is based on random stimulations presented in a blinded sequence to 10 stimulation sites. ⋯ The RRF area, RRF volume and location of the peak reflex response appear to be the most sensitive measures for detecting modulation of spinal nociceptive processing. This new method has important potential applications for exploring aspects of central plasticity in volunteers and patients. It may be utilized as a new diagnostic tool for central hypersensitivity and quantification of therapeutic interventions.
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J. Neurosci. Methods · Mar 2009
Case ReportsTemporally resolved differential proteomic analysis of human ventricular CSF for monitoring traumatic brain injury biomarker candidates.
A shotgun proteomic approach based on nanoflow liquid chromatography (nanoLC) in conjunction with matrix assisted laser desorption/ionization time of flight tandem mass spectrometry (MALDI TOF MS/MS) was utilized to quantitatively analyze the protein content of consecutive ventricular cerebrospinal fluid (CSF) samples of severe traumatic brain injury (TBI) patients on an individual basis. CSF was acquired from the lateral ventricle 1-9 days after the TBI incident by canula drain to investigate temporally resolved protein changes in three patients that required intracranial pressure monitoring during neurointensive care. ⋯ Certain suggested protein-biomarker candidates for TBI, like acute phase reactants (APRs), fibrinogens (FIB), cystatin C (CC) or more brain specific proteins like glial fibrillary acid protein (GFAP) and neuron-specific enolase (NSE) were found to be significantly up-regulated which is in strong consistence with previously reported results. This methodology appears to be a promising tool for studying candidate biomarkers of neurovascular and traumatic brain injuries in the neurointensive care setting.
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J. Neurosci. Methods · Mar 2009
Von Frey's hairs--a review of their technology and use--a novel automated von Frey device for improved testing for hyperalgesia.
We describe a device which allows the mechanical sensitivity of trigeminovascular sensory neurons to be monitored over extended time periods. The device can be used to stimulate either the skin or dura mater and consists of a solenoid-driven plunger to which are fixed interchangeable von Frey hairs. ⋯ The advantages of the device over manual stimulation include the reproducibility of the site of stimulation; the ability to apply a known force for a known time; the ability to measure response latencies to millisecond precision and to compare them to latencies to other stimuli and; easy interface with computer-control. We discuss some of the drawbacks of the von Frey system as usually used and illustrate the use of the new device with results from experiments on peripherally induced sensitization.
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J. Neurosci. Methods · Mar 2009
Extracellular recordings from locally dense microelectrode arrays coupled to dissociated cortical cultures.
High-density microelectrode arrays (MEAs) enabled by recent developments of microelectronic circuits (CMOS-MEA) and providing spatial resolutions down to the cellular level open the perspective to access simultaneously local and overall neuronal network activities expressed by in vitro preparations. The short inter-electrode separation results in a gain of information on the micro-circuit neuronal dynamics and signal propagation, but requires the careful evaluation of the time resolution as well as the assessment of possible cross-talk artifacts. In this respect, we have realized and tested Pt high-density (HD)-MEAs featuring four local areas with 10microm inter-electrode spacing and providing a suitable noise level for the assessment of the high-density approach. ⋯ This limiting condition is not compatible with typical experimental conditions (i.e. dense but not confluent cultures). Experiments performed on spontaneously active cortical neuronal networks show that spike synchronicity decreases by increasing the time resolution and analysis results show that the detected synchronous spikes on nearby electrodes are likely to be unresolved (in time) fast local propagations. Finally, functional connectivity analysis results show stronger local connections than long connections spread homogeneously over the whole network demonstrating the expected gain in detail provided by the spatial resolution.