Informatics

The brain is a massively interconnected network of specialized circuits. Understanding how these circuits support sensation, perception, cognition, and action requires measuring activity patterns within and across regions, but the measurements themselves do not produce insight into the structure or function of the underlying neuronal system. Insight requires the applications of quantitative methods that relate neuronal activity patterns to experimentally measurable variables, including things like present and past sensory inputs, current location, and current or future motor outputs.

The Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative promotes the development and application of technologies to describe the temporal and spatial dynamics of cell types and neural circuits in the brain.

PROJECT SUMMARY Brain image data collected by the neuroscience community will continue to grow dramatically in the next 5-10 years as the push to image physically larger volumes, such as whole brains from humans and other primates, becomes a focus. The scientific community, with the support of

Project Summary Understanding cell-type-specific gene functions, expression dynamics, and regulatory mechanisms in complex brains is still challenging.

PROJECT SUMMARY/ABSTRACT Intracranial recordings in patients undergoing neurosurgical interventions provide a unique opportunity to directly access, study, and learn about both normal human brain function and neuropsychiatric disease. Because of their value, the

PROJECT SUMMARY Neurons in the visual cortex form an intricate connectivity structure and topographic arrangement. The structural and morphological organization of the neurons is known to constrain its functional properties. To understand these constraints, it is necessary to generate large-scale anatomical and functional measurements of the brain. Ongoing efforts in electron microscopy (EM) and fluorescent microscopy promise to massively accelerate the speed of generating such data.

Project Summary A key goal in neuroscience is determining how microcircuit structure predicts circuit function. An intriguing idea, supported by some theoretical models, is that variation in microcircuit composition supports functional specialization. This theory has received support from the observation of a correlation between gradients in circuit properties (receptor expression densities; inhibitory cell types) and in measurements of average intrinsic timescales of recorded activity across cortical areas.

Project Summary The neuroscience community is experiencing a revolution in its ability to share and analyze vast amounts of human brain imaging data, with support from the BRAIN Initiative and other substantial data-sharing efforts.

Project Summary Estimates of the total length of axonal "wiring" in the human brain are on the order of hundreds of thousands of kilometers. Understanding the fundamental principles underlying the connectivity between cells is a daunt- ing task, but it has become increasingly clear that there are canonical connectivity patterns across the layers of the mammalian cortex.

Summary Functional Magnetic Resonance Imaging data has been a mainstay of neuroscience research for more than two decades, as it allows rapid, continuous, noninvasive monitoring of neuronal function. However, a substantial portion of the fMRI signal arises from purely physiological cerebral hemodynamic signals in the low and cardiac frequency bands.