Summary John Frederic Daniell (1790–1845) invented the constant battery in 1836. He meant it to be a philosophical instrument to be utilized in both lecture demonstrations and electrochemical laboratory research. But the constant battery was taken up in electrometallurgy, not primarily as a source of electric current but more as an electrodeposition device. As such it became an essential tool in the development of galvanoplastics (electroforming). This article traces the tortuous transformation of this lecture demonstration apparatus into an electrometallurgical tool, (...) and includes some aspects of British and French patent laws, and the electrogilding industry. (shrink)

Technologies for deriving human neurons in vitro have transformed our ability to study cellular and molecular components of human neurotransmission. Three groups, including our own, have recently published methods for efficiently generating human serotonergic neurons in vitro. Remarkably, serotonergic neurons derived from each method robustly produce serotonin, express raphe genes, are electrically active, and respond to selective serotonin reuptake inhibitors in vitro. Two of the methods utilize transdifferentiation technology by overexpressing key serotonergic transcription factors. The third and most recent method (...) involves differentiating induced pluripotent stem cells (iPSCs) to serotonergic neurons using developmental patterning cues. In this mini‐review, we briefly describe the developmental programs governing serotonergic specification in vivo and how they have been harnessed to achieve serotonergic differentiation in vitro. We discuss the distinct and overlapping features of the recently published methodologies and their value in the context of in vitro disease modeling.Also see the video abstract here. (shrink)