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Waitt Advanced Biophotonics Center

Meet the Scientists

Salk Institute for Biological Studies - Waitt Advanced Biophotonics Center - Meet the Scientists

Meet the Scientists

 
Axel Nimmerjahn

Axel Nimmerjahn, PhD

Professor and Director
Waitt Advanced Biophotonics Center
Francoise Gilot Chair

Innovations and Discoveries:

  • Using imaging and genetic approaches the Nimmerjahn lab has uncovered how microglia, the resident innate immune cells of the central nervous system (CNS), recognize and respond to disturbances in brain function, and how this knowledge can be leveraged to control inflammatory conditions.
  • Nimmerjahn's lab has spearheaded the development of new microscopy techniques to measure how cells in the spinal cord encode sensory information. The team showed that astrocytes, a major regulatory cell type in the CNS, show coordinated activity in response to noxious but not innocuous cutaneous stimuli. The findings point to new and unanticipated roles of these cells in pain disorders.
  • Nimmerjahn and colleagues used cutting-edge microscopy approaches to visualize the blood-brain barrier (BBB) breakdown after stroke. They found that stepwise impairment of different cellular mechanisms accounts for the BBB deficits in stroke, pointing to new ways to treat the disease.
Edward Callaway

Edward Callaway

Professor
Systems Neurobiology Laboratory
Vincent J. Coates Chair in Molecular Neurobiology

Innovations and Discoveries:

  • Callaway's lab developed a tool that uses a modified rabies virus to trace single connections between neurons, a technique now used across the world.
  • The lab used its novel circuit-tracing methods to obtain a detailed map of connections to specific cell types in the basal ganglia, an area of the brain linked to both movement and decision-making and implicated in Parkinson's and Huntington's diseases. These studies provide insight into how different cell types in the basal ganglia structure contribute to motor control and decision-making.
  • Callaway mapped the connections between cells in the retina of the eye and the brain and discovered that there's a unique highway of connections that has the sole purpose of letting the eye and brain work together to sense up-and-down or side-to-side movement.
Adam Bowman

Adam Bowman

Salk Fellow

Innovations and Discoveries:

  • Bowman developed new technologies for fast gating of wide-field images, which allow a standard camera sensor—like one in a cell phone—to capture nanosecond time information, bridging six orders of magnitude in temporal scale.
  • Bowman deployed this technology to enable electro-optic fluorescence lifetime microscopy (EO-FLIM), which has allowed wide-field measurements of fluorescence lifetime with single-molecule sensitivity.
  • Bowman demonstrated that EO-FLIM can be used to record action potentials and neuron membrane potential in live cells and tissues at kilohertz frame rates using a genetically encoded voltage indicator.
Samuel Pfaff

Samuel Pfaff

Professor
Gene Expression Laboratory
Benjamin H. Lewis Chair

Innovations and Discoveries:

  • The Pfaff lab discovered neurons within the spinal cord that form a critical regulatory node for controlling motor activity and developed mouse lines that permit spinal neuron activity to be visualized during walking.
  • The lab created an in vitro model of spinal muscular atrophy to define the fundamental underpinnings of the genetic pathways that go awry in this disease. The group also worked with a team of San Diego scientists to develop an ALS therapy for humans.
  • Pfaff's lab used genome sequencing to identify molecular pathways involved in gene regulation and spinal cord development. Using this knowledge, they successfully created functional spinal motor circuitry from embryonic stem cells.
Rusty Gage

Rusty Gage

Professor
Laboratory of Genetics
Vi and John Adler Chair for Research on Age-Related Neurodegenerative Disease

Innovations and Discoveries:

  • The Gage lab models diseases in the laboratory using stem cell technologies. They showed that neurons generated from the skin cells of people with schizophrenia are dysfunctional in early developmental stages, providing a hint as to ways to detect and potentially treat the disease early.
  • By sequencing the genomes of single cells, Gage and collaborators showed that the genomic structures of individual neurons differ from each other even more than expected. This may help explain differences between closely related individuals.
  • Gage and his colleagues discovered that the human brain can give rise to new neurons throughout life. He also found that exercise and cognitive enrichment can increase the brain's ability to generate more neurons.
Eiman Azim

Eiman Azim

Associate Professor
Molecular Neurobiology Laboratory
William Scandling Developmental Chair

Innovations and Discoveries:

  • Azim identified circuits dedicated to controlling specific features of movement, supporting the idea that there is a modular organization to the motor system, meaning that certain circuits control reaching, others control grasping, and so on. His work helps show that this organization is shared across mammal species.
  • Azim investigated inhibitory neurons in the spinal cord that control the strength of incoming sensory feedback and showed that this circuit is essential for maintaining the stability of the limb during movement.
  • Azim mapped a spinal circuit that conveys copies of motor commands within the nervous system, helping to keep the brain aware of its ongoing output. His research showed that these internal copy signals get channeled through part of the brain called the cerebellum and can be used to update movements very rapidly, supporting the speed and precision of skilled behaviors.
Martyn Goulding

Martyn Goulding

Professor
Molecular Neurobiology Laboratory
Frederick W. and Joanna J. Mitchell Chair

Innovations and Discoveries:

  • The Goulding laboratory has established a comprehensive genetic toolkit and set of sophisticated behavioral tests that allows them to functionally dissect the circuits in the spinal cord that process sensory information and generate coordinated body movements.
  • Goulding has leveraged his expertise in spinal neural circuitry to define the pathways that transmit and gate itch and pain, providing a better understanding of the cellular changes that underlie chronic pain and itch.
  • Goulding's lab has delineated the role that multiple neuronal cell types play in controlling locomotion. A better understanding of these circuits should eventually aid in developing therapies for diseases that affect motor skills and balance.
Talmo Pereira

Talmo Pereira

Salk Fellow

Innovations and Discoveries:

  • Pereira’s pioneering work demonstrated how deep learning could be used to achieve markerless motion capture in animals that enables detailed quantification of behavior.
  • Pereira and his team have developed SLEAP, an open-source software tool that makes AI-based motion capture technology accessible to non-technical users. SLEAP is now in use by thousands of researchers all around the world to study everything from subcellular organelles to whale sharks.
  • Pereira and his team have shown how artificial neural networks can be used to simulate how real brains process information.
Tatyana Sharpee

Tatyana Sharpee

Professor
Computational Neurobiology Laboratory
Edwin K. Hunter Chair

Innovations and Discoveries:

  • Tatyana Sharpee is using advanced methods from mathematics, statistics and physics to chart the principles by which neurons in the brain and spinal cord exchange energy and information.
  • Sharpee developed a concise scheme for how visual neurons can combine selectivity to shapes and textures of visual objects.
  • Sharpee and collaborators have generated a theory that explains when it becomes advantageous for an organism to use new types of neurons. This theory could help catalogue and determine the number of separate neuronal types in the brain. Extensions of this theory make it possible to compute how much information large numbers of neurons jointly convey about incoming stimuli. Previously, this was only possible to do for a few neurons, and now the method can keep up with the capacity of experimental methods that record thousands of neurons simultaneously.
Terrence Sejnowski

Terrence Sejnowski

Professor and Laboratory Head
Computational Neurobiology Laboratory
Francis Crick Chair

Innovations and Discoveries:

  • The Sejnowski lab is using computer modeling techniques to try to encapsulate what we know about the brain as well as to test hypotheses on how brain cells process, sort and store information.
  • They developed a new model for how memories are consolidated—or stored in the brain—during sleep. Researchers hypothesized some memories are strengthened during sleep, while other memories, deemed less important, are lost. Revealing more about how the brain stores memories could help researchers understand how memory is affected in disorders such as Alzheimer's disease.
  • Sejnowski built upon a computer model of how neurons transmit electrical impulses and found an unexpected link between a cellular channel and a potassium current—the ratio of densities between the two determines whether neurons can fire properly, providing new knowledge for symptoms of multiple sclerosis.