Peter Drummond

Purpose: Complex regional pain syndrome (CRPS) is a neuropathic pain condition that can be acquired after minor trauma or surgery to soft tissues and nerves. Biopsies from affected tissue show an increased density of α1-adrenergic receptors (AR1) compared to controls. In order to further study the role of AR1 in CRPS, we wish to use an immortalized cortical neuron cell line, NIE115. The present study aimed to (i) characterise the expression of AR1 on NIE115 cells and (ii) document how the metabolic profile of NIE115 cells is affected by adrenergic pharmacological intervention. Methods: NIE115 cultures (n = 15) were dual-or triple-labelled with antibodies directed against AR1 as well as specific neuronal markers (neurofilament, TRPV1, TUJ1, CGRP). Cells were then exposed to an AR1 agonist (phenylephrine, n = 18), an antagonist (prazosin, n = 12) or a combination of both (n = 12) and the biochemical effects studied using gas chromatography-mass spectrometry-based metabolomics. Results: Immunohistochemistry confirmed the presence of AR1 on the NIE115 cells. Treatment of the cells with phenylephrine led to changes in both carbon and nitrogen metabolism consistent with stimulation of AR1. It was expected that prazosin would block the metabolic effects of phenylephrine, but a different set of changes to carbon and nitrogen metabolism were observed. This provides further evidence to the observations that prazosin may in fact be acting as an inverse agonist. Conclusion: These data indicate that metabolomics is a powerful technology in the study of receptor signaling, and have provided us with a new tool to investigate CRPS.

Digital video recorders have made it easier for television viewers to avoid ads by fast forwarding and ad skipping. If viewers skip to avoid ads, they would not be interested in the next ad they skip to. Alternatively, if viewers skip because the current ad is uninteresting, they may still be receptive to the next ad, provided it was interesting for them. Data from 52 students was used to measure skin conductance (SCL) before and after skipping and to investigate whether ad skipping was followed by heart rate deceleration. Data from 5 seconds before and after viewer-controlled ad skips were compared to the same time period before and after the change from one commercial to another. SCL began increasing three seconds prior to ad skipping and continued to increase until three seconds after the ad skip, whereas there was a downward trend across natural commercial changes, so that average SCL was higher in response to skipped ads. These results indicate the decision to skip is associated with increased physiological arousal, consistent with mobilizing physical resources to press the skip button. Males appear to skip to avoid, whereas female skippers are potentially still receptive to the next ad, following a skip.