Exploring Neurotechnologies

In this special issue of Neuron, we are prou d to present a collection of Reviews, Perspectives, and NeuroViews that offer a snapshot into some of the most exciting recent advances in neuroengineering. Undeniable strides have beenmade in our understanding of the genetic, molecular, and physiological mechanisms that contribute to brain function, and the development and dissemination of state of the art neurotechnologies have driven progress faster and further than ever before. Continuing technology development is paramount for expanding the resolution and scale of available methods to measure and manipulate neural cells and circuits. This will require the collaboration of scientists across disciplines, from basic neurobiology to computer science, engineering, optics, and more. In this special issue, we bring together the perspectives of scientists working across diverse fields, yet all at the vanguard of technology development. We hope these articles will offer readers technical insight into the strengths and challenges of current technologies, alongside critical discussion as to how far we have come—and how much further we need to go—to unlock the mysteries of the brain.While not intended to offer comprehensive coverage of all existing neurotechnologies, we hope that the collection we have put together—including topics frommaterials science, nanoscience, stem cell biology, imaging, optogenetics, electrophysiology, prosthetics, and engineering—provides a sense of the work ongoing throughout the field. We start the issue ‘‘small,’’ with insights from John Rogers and Charles Lieber, together with their colleagues, discussing the promise of newmaterials and nanotechnology and the technical considerations for the generation of new probes. Given the importance of physiological recording and imaging to neuroscience, we have three articles that discuss advances in these areas. György Buzsáki and collaborators present an overview of large-scale electrophysiological recording methods combined with focused optogenetics, while Logan Grosenick, James H. Marshel, and Karl Deisseroth discuss optoelectronic as well as all-optical technologies to allow closed-loop control of neurons and behavior. Mark Schnitzer and co-workers present their perspective on the use of fluorescent indicators to map activity at the cellular level in behaving animals. A theme that emerges from these pieces is that much can be learned by emulating aspects of engineering disciplines and culture to help coordinate efforts among users and developers of probes and instrumentation for continued advancement in physiological recording, stimulation, and imaging. Turning the lens to work in non-human primates and humans, Karen Moxon and Guglielmo Foffani discuss brain-machine interfaces beyond neuroprosthetics. They cover a historical perspective of the field and future applications, both to improve function after injury and as a tool to probe basic features of the nervous system. Grégoire Courtine and Jocelyne Bloch present an original analogy in their thinking about ways to improve neuroprosthetic design and, eventually, clinical treatment. Continuing with a translational bent, in their Perspective, Lena Ting and colleagues suggest that applying concepts from neuromechanics may help guide testing and training for motor recovery after injury or stroke. Two contributions from clinical neuroscientists, Edward Chang and the collaboration of Sydney Cash and Leigh Hochberg, review methods to register neurophysiological activity at intermediate scales and at the single-neuron level in humans. These authors also discuss how basic findings may inform the development of therapeutic strategies for neurological and psychiatric disorders. On a different end of the technology spectrum, Julius Steinbeck and Lorenz Studer provide an authoritative and sobering review of the therapeutic potential and limitations of stem cell-based technologies for brain repair. Steven Finkbeiner partners with Michael Frumkin from Google and Paul Kassner from Amgen to illustrate how large-scale screening of single cells can help understand the basic biology of disease and may help guide therapeutic development. They also introduce machine learning as a useful tool to understand complex data sets, a topic tackled head on by Moritz Helmstaedter in a NeuroView essay where he gives examples of other important uses of machine learning and discusses how neuroscience can in turn synergize the development of new algorithms. One common thread that comes across in the pieces in this issue is that these approaches are generating large amounts of data, which require proper analysis and management. It is clear that the next generation of neuroscientists will need a strong command of analytical and technical skills to meaningfully perform and interpret experiments, and Brian Litt in his piece eloquently calls for improved and thorough training programs in neuroscience. Finally, we’ve asked Martha Farah to write on the societal impact of technology and neuroscience, and she elegantly provides a didactic compendium of ethics concepts to facilitate discussions around these topics. We are indebted to the many authors and reviewers who thoughtfully contributed to this special issue, and we would like to apologize to all whose exciting developments we haven’t yet had the chance to cover. In keepingwithNeuron’s philosophy of staying at the forefront of the field, we invite you to submit your latest innovation and to share the lessons learned with our audience. This year’s Neuron satellite symposium at the Society for Neuroscience meeting is entitled ‘‘Engineering the Brain: Technologies for Neurobiological Applications,’’ where we’ll continue the conversation about new tools, as well as discuss how to catalog, share, and begin to make sense of the data that emerge from these approaches. Please check the website for the latest program developments and submit your abstract (www.cell-symposia-engineeringthebrain.com). The reviews and opinion pieces in this issue will be part of a free digital edition available at www.cell.com/neuron, thanks to the generous support of Cellular Dynamics. We hope you enjoy these articles and that you share our anticipation for what these and other technologies will uncover in the future.