The Ca(2+)-triggered merger of two apposed membranes is the defining step of regulated exocytosis. CHOL is required at critical levels in secretory vesicle membranes to enable efficient, native membrane fusion: CHOL-sphingomyelin enriched microdomains organize the site and regulate fusion efficiency, and CHOL directly supports the capacity for membrane merger by virtue of its negative spontaneous curvature. Specific, structurally dissimilar lipids substitute for CHOL in supporting the ability of vesicles to fuse: diacylglycerol, alphaT, and phosphatidylethanolamine support triggered fusion in CHOL-depleted vesicles, and this correlates quantitatively with the amount of curvature each imparts to the membrane. Lipids of lesser negative curvature than cholesterol do not support fusion. The fundamental mechanism of regulated bilayer merger requires not only a defined amount of membrane-negative curvature, but this curvature must be provided by molecules having a specific, critical spontaneous curvature. Such a local lipid composition is energetically favorable, ensuring the necessary "spontaneous" lipid rearrangements that must occur during native membrane fusion-Ca(2+)-triggered fusion pore formation and expansion. Thus, different fusion sites or vesicle types can use specific alternate lipidic components, or combinations thereof, to facilitate and modulate the fusion pore.

These results demonstrate the potential for an intracortical BCI to be used immediately after deployment by people with paralysis, without the need for user learning or extensive system calibration.

Brain Computer Interfaces (BCIs) use neural information recorded from the brain for voluntary control of external devices. The development of BCI systems has largely focused on improving functional independence for individuals with severe motor impairments, including providing tools for communication and mobility. In this review, we describe recent advances in intracortical BCI technology and provide potential directions for further research.

A wide range of methods exist for the on-plate detection of lipids resolved by thin layer chromatography. Fluorescence generally offers improvements in sensitivity over methods that use colorimetric or simple densitometric detection. In this paper, we report that a classic cupric sulfate charring protocol produces a fluorescent signal that sensitively and quantitatively detects a wide range of phospholipids, neutral lipids, and sterols after automated, multi-development high performance thin layer chromatography. The measured lower limits of detection and quantification, respectively, were, on average, 80 and 210 pmol for phospholipids and 43 fmol and 8.7 pmol for sterols. The simple, inexpensive, and highly sensitive approach described here was used to quantitatively analyze the lipid and sterol composition of sea urchin cortical vesicles, a stage-specific model system used to study the mechanism of regulated membrane fusion.