Near-infrared fluorescent protein iRFP713 as a reporter protein for optogenetic vectors, a transgenic Cre-reporter rat, and other neuronal studies.

Background: The use of genetically-encoded fluorescent reporters is essential for the identification and observation of cells that express transgenic modulatory proteins. Near-infrared (NIR) fluorescent proteins have superior light penetration through biological tissue, but are not yet widely adopted.

New Method: Using the near-infrared fluorescent protein, iRFP713, improves the imaging resolution in thick tissue sections or the intact brain due to the reduced light-scattering at the longer, NIR wavelengths used to image the protein.

A TRP channel in the lysosome regulates large particle phagocytosis via focal exocytosis.

Phagocytosis of large extracellular particles such as apoptotic bodies requires delivery of the intracellular endosomal and lysosomal membranes to form plasmalemmal pseudopods. Here, we identified mucolipin TRP channel 1 (TRPML1) as the key lysosomal Ca2+ channel regulating focal exocytosis and phagosome biogenesis. Both particle ingestion and lysosomal exocytosis are inhibited by synthetic TRPML1 blockers and are defective in macrophages isolated from TRPML1 knockout mice.

Genetic dissection of the role of catechol-O-methyltransferase in cognition and stress reactivity in mice.

The COMT (catechol-O-methyltransferase) gene has been linked to a spectrum of human phenotypes, including cognition, anxiety, pain sensitivity and psychosis. Doubts about its clinical impact exist, however, because of the complexity of human COMT polymorphism and clinical variability. We generated transgenic mice overexpressing a human COMT-Val polymorphism (Val-tg), and compared them with mice containing a null COMT mutation.