Objective Melittin is the main peptide in bee venom and causes both persistent spontaneous nociception and pain hypersensitivity. Our recent studies indicated that both transient receptor potential (TRP) vanilloid receptor 1 (TRPV1) and canonical TRPs (TRPCs) are involved in mediating the melittin-induced activation of different subpopulations of primary nociceptive cells. Here, we further determined whether TRPC channels are involved in melittin-induced inflammatory nociceptive responses in behavioral assays. Methods The anti-nociceptive and anti-hyperalgesic effects of localized peripheral administration of three doses of the non-selective TRPC antagonist, SKF-96365 (1-{β-[3-(4-methoxyphenyl) propoxy]-4-methoxyphenyl}-1H-imidazole hydrochloride), were evaluated in melittin tests. Pain-related behaviors were rated by counting the number of paw flinches, and measuring paw withdrawal thermal latency (s) and paw withdrawl mechanical threshold (g), over a 1-h time-course. Results Localized peripheral SKF-96365 given before melittin prevented, and given after melittin significantly suppressed, the melittin-evoked persistent spontaneous nociception. Pre-blockade and post-suppression of activation of primary nociceptive activity resulted in decreased hypersensitivity to both thermal and mechanical stimuli applied to the primary injury site of the ipsilateral hindpaw, despite dose-effect differences between thermal and mechanical hyperalgesia. However, local administration of SKF-96365 into the contralateral hindpaw had no significant effect on any pain-associated behaviors. In addition, SKF-96365 had no effect on baseline threshold for either thermal or mechanical sensitivity under normal conditions. Conclusion Besides TRPV1, SKF-96365-sensitive TRPC channels might also be involved in the pathophysiological processing of melittin-induced inflammatory pain and hypersensitivity. Therapeutically, SKF-96365 is equally effective in preventing primary thermal and mechanical hyperalgesia as well as persistent spontaneous noc
Simultaneous multisite recording using multi-electrode arrays(MEAs) in cultured and acutely-dissociated brain slices and other tissues is an emerging technique in the field of network electrophysiology.Over the past 40 years,great efforts have been made by both scientists and commercial concerns,to advance this technique.The MEA technique has been widely applied to many regions of the brain,retina,heart and smooth muscle in various studies at the network level.The present review starts from the development of MEA techniques and their uses in brain preparations,and then specifically concentrates on the use of MEA recordings in studies of synaptic plasticity at the network level in both the temporal and spatial domains.Because the MEA technique helps bridge the gap between single-cell recordings and behavioral assays,its wide application will undoubtedly shed light on the mechanisms underlying brain functions and dysfunctions at the network level that remained largely unknown due to the technical difficulties before it matured.
