Re-evaluating the Quoit Brooch Style: Economic and Cultural Transformations in the 5th Century ad, with an Updated Catalogue of Known Quoit Brooch Style Artefacts

Quoit Brooch Style material, produced from the early 5th century onwards, has previously been considered mostly from a stylistic point of view, leaving much scope for further investigation. In addition, the known corpus of material has been much expanded through newly excavated and metal-detected finds. In this article, I bring together the known extant material for the first time, and document important evidence relating to contextual dating, gender associations, manufacture (including new compositional analysis of c 75 objects), repair, and reuse. The article questions previous interpretations of Quoit Brooch Style material relating to Germanic mercenaries and/or post-Romano-British political entities. It interprets the earliest material as part of wider trends elsewhere, in Britain and in Continental northwestern Europe, for the production of material imitating late Roman symbols of power. It presents new evidence for connectivity with Continental Europe via the western Channel route in the 5th century. A detailed investigation of individual artefacts shows that many Quoit Brooch Style objects were reused, sometimes being subjected to extensive repair and modification. This provides new insights into the 5th century metal economy, for instance, acute problems in the availability of new metal objects in southeastern Britain in the middle years of the 5th century. Compositional analysis contributes further to our understanding of metal supply in the 5th century and relationships with the post-Roman West. Insights are provided into wider cultural transformations in the 5th century and the gradual loss of value that occurred for Roman-style objects

Hyperforin - a key constituent of St. Johns wort specifically activates TRPC6 channels

Hyperforin, a bicyclic polyprenylated acylphloroglucinol derivative, is the main active principle of St. Johns wort extract responsible for its antidepressive profile. Hyperforin inhibits the neuronal serotonin and norepinephrine uptake comparable to synthetic antidepressants. In contrast to synthetic antidepressants directly blocking neuronal amine uptake, hyperforin increases synaptic serotonin and norepinephrine concentrations by an indirect and yet unknown mechanism. Our attempts to identify the molecular target of hyperforin resulted in the identification of TRPC6. Hyperforin induced sodium and calcium entry as well as currents in TRPC6-expressing cells. Sodium currents and the subsequent breakdown of the membrane sodium gradients may be the rationale for the inhibition of neuronal amine uptake. The hyperforin-induced cation entry was highly specific and related to TRPC6 and was suppressed in cells expressing a dominant negative mutant of TRPC6, whereas phylogenetically related channels, i.e., TRPC3 remained unaffected. Furthermore, hyperforin induces neuronal axonal sprouting like nerve growth factor in a TRPC6-dependent manner. These findings support the role of TRPC channels in neurite extension and identify hyperforin as the first selective pharmacological tool to study TRPC6 function. Hyperforin integrates inhibition of neurotransmitter uptake and neurotrophic property by specific activation of TRPC6 and represents an interesting lead-structure for a new class of antidepressants