Underground testing : name-altering practices as probes in electronic music

Name-altering practices are common in many creative fields – pen names in literature, stage names in the performing arts, aliases in music. More than just reflecting artistic habits or responding to the need for distinctive brands, these practices can also serve as test devices to probe, validate, and guide the artists’ active participation in a cultural movement. At the same time, they constitute a powerful probe to negotiate the boundaries of a subculture, especially when its features are threatened by appropriation from the mass-oriented culture. Drawing evidence from electronic music, a field where name-altering practices proliferate, we outline dynamics of pseudonymity, polyonymy, and anonymity that surround the use of aliases. We argue that name-altering practices are both a tool artists use to probe the creative environment and a device to recursively put one’s creative participation to the test. In the context of creative subcultures, name-altering practices constitute a subtle but effective form of underground testing

Aη-α and Aη-β peptides impair LTP ex vivo within the low nanomolar range and impact neuronal activity in vivo

Background: Amyloid precursor protein (APP) processing is central to Alzheimer’s disease (AD) etiology. As early cognitive alterations in AD are strongly correlated to abnormal information processing due to increasing synaptic impairment, it is crucial to characterize how peptides generated through APP cleavage modulate synapse function. We previously described a novel APP processing pathway producing η-secretase-derived peptides (Aη) and revealed that Aη–α, the longest form of Aη produced by η-secretase and α-secretase cleavage, impaired hippocampal long-term potentiation (LTP) ex vivo and neuronal activity in vivo. Methods: With the intention of going beyond this initial observation, we performed a comprehensive analysis to further characterize the effects of both Aη-α and the shorter Aη-β peptide on hippocampus function using ex vivo field electrophysiology, in vivo multiphoton calcium imaging, and in vivo electrophysiology. Results: We demonstrate that both synthetic peptides acutely impair LTP at low nanomolar concentrations ex vivo and reveal the N-terminus to be a primary site of activity. We further show that Aη-β, like Aη–α, inhibits neuronal activity in vivo and provide confirmation of LTP impairment by Aη–α in vivo. Conclusions: These results provide novel insights into the functional role of the recently discovered η-secretase-derived products and suggest that Aη peptides represent important, pathophysiologically relevant, modulators of hippocampal network activity, with profound implications for APP-targeting therapeutic strategies in AD