This study examined the distribution of serotoninergic (5-HT) immunoreactive axonal contacts on spinal laminae I and II neurons by combining the intracellular horseradish peroxidase (HRP) method with immunocytochemistry. In addition, the 5-HT distribution was correlated with effects produced by electrical stimulation within the nucleus raphe magnus (NRM). Responses of lamina I neurons and lamina II stalked cells to noxious stimulation were markedly suppressed during NRM stimulation. In contrast, responses of nociceptive lamina IIa islet or non-nociceptive lamina IIb islet cells remained unchanged during nucleus raphe magnus stimulation. These inhibitory influences were positively correlated with the distribution of 5-HT immunoreactive contacts on these neurons. Nociceptive lamina I neurons and lamina II stalked cells received a significantly greater number of contacts (average of 74 and 63, respectively) than either nociceptive lamina IIa islet or non-nociceptive lamina IIb islet cells (average of 25 and eight contacts, respectively). Irrespective of cell type, most 5-HT contacts occurred on dendritic shafts rather than spines. These data reveal a differential distribution of 5-HT contacts on neurons in spinal laminae I and II, and indicate that at least a portion of the NRM modulation of dorsal horn neuronal activity is serotoninergic and concentrated on the dendritic shafts of nociceptive lamina I neurons and lamina II stalked cells.
We conducted a multicenter, double-blind, parallel-group study to compare the efficacy and safety of dihydroergotamine (DHE) nasal spray and placebo over 4 hours in the treatment of migraine. Of the 112 patients enrolled, 100 were included in the "intent-to-treat" efficacy analysis. The patients self-administered either 2.0 mg DHE (0.5 mg per nostril, repeated after 15 minutes) or placebo at the onset of two separate headaches and rated hourly the drugs' effects on pain severity, pain relief, nausea, and vomiting. The physicians assessed the overall effectiveness of the drugs in relieving headache pain, nausea, and vomiting. Both the patients' and physicians' ratings indicated that DHE was significantly superior to placebo in improving headache and nausea; according to the patients' ratings, these between-group differences were already significant at the first (hour 1) evaluation. There were no significant differential treatment effects with respect to relief of vomiting. Most adverse events were mild or moderate, confined to the nasopharyngeal area, and probably related to the route of administration. We conclude that DHE nasal spray is a safe and effective treatment for the pain and nausea of migraine attacks.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.