Circuit Diagrams

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.

Project Summary Brain-computer interfaces (BCIs) have emerged as a promising modality for restoring physiological functions such as mobility, communication, and visual perception.

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.

PROJECT SUMMARY In this proposal we aim to identify gene regulatory elements that permit the targeting and manipulation of brain circuit models of human brain function. Gaining genetic access to specific neuron populations in nontransgenic animals and humans would enable targeted circuit modulation for hypothesis testing and provide a means to evaluate the safety and efficacy of circuit modulation for the treatment of epilepsy and psychiatric disorders.

Project Summary The human brain contains an astonishing diversity of neuronal and glial cell types distributed across dozens of functional areas.

ABSTRACT Reproducible findings are essential to scientific advancement. Unfortunately, when fields lack consensus standards for methods, or their implementations, reproducibility tends to be more of an ideal than a reality.

Adeno-Associated Viruses (AAVs) are potent gene delivery vectors for neuroscience studies and gene therapy applications. However, naturally occurring AAVs are not cell type specific: they must be combined with other technologies, such as transgenic animals, to achieve cell type specific gene expression.