Technologies for Understanding and Repairing the Brain

<!--HTML--><p>Understanding and repairing the brain requires new physics and chemistry-based technologies that enable the brain to be mapped and controlled with great precision.&nbsp; We recently discovered that it was possible to physically magnify the brain manyfold in size, in an even way, by embedding brain tissues in dense swellable polymers, and then adding water to isotropically swell the brains evenly.&nbsp; This method, which we call expansion microscopy (ExM), enables large-volume imaging of brain circuits, with nanoscale precision.&nbsp; As another example, we discovered that microbial opsins, genetically expressed in neurons, could enable their electrical activities to be precisely driven or silenced in response to millisecond timescale pulses of light.&nbsp; These tools, called optogenetic tools, are enabling causal assessment of the contribution of defined neurons to behaviors and pathologies in a wide variety of basic science settings.&nbsp; We share these tools freely, and aim to integrate the use of these tools so as to lead to comprehensive understandings of neural circuits.&nbsp; Ultimately we aim for realistic, understandable computational models of how the brain works.</p>