Education & Certifications

  • Master of Science, Stanford University, BIOE-MS (2017)
  • Bachelor of Science, California Institute of Technology, Bioengineering, Business Economics and Management (2015)

All Publications

  • Deep brain optogenetics without intracranial surgery. Nature biotechnology Chen, R., Gore, F., Nguyen, Q. A., Ramakrishnan, C., Patel, S., Kim, S. H., Raffiee, M., Kim, Y. S., Hsueh, B., Krook-Magnusson, E., Soltesz, I., Deisseroth, K. 2020


    Achieving temporally precise, noninvasive control over specific neural cell types in the deep brain would advance the study of nervous system function. Here we use the potent channelrhodopsin ChRmine to achieve transcranial photoactivation of defined neural circuits, including midbrain and brainstem structures, at unprecedented depths of up to 7 mm with millisecond precision. Using systemic viral delivery of ChRmine, we demonstrate behavioral modulation without surgery, enabling implant-free deep brain optogenetics.

    View details for DOI 10.1038/s41587-020-0679-9

    View details for PubMedID 33020604

  • Interacting neural ensembles in orbitofrontal cortex for social and feeding behaviour. Nature Jennings, J. H., Kim, C. K., Marshel, J. H., Raffiee, M., Ye, L., Quirin, S., Pak, S., Ramakrishnan, C., Deisseroth, K. 2019


    Categorically distinct basic drives (for example, for social versus feeding behaviour1-3) can exert potent influences on each other; such interactions are likely to have important adaptive consequences (such as appropriate regulation of feeding in the context of social hierarchies) and can become maladaptive (such as in clinical settings involving anorexia). It is known that neural systems regulating natural and adaptive caloric intake, and those regulating social behaviours, involve related circuitry4-7, butthe causal circuit mechanisms of these drive adjudications are not clear. Here we investigate the causal role in behaviour of cellular-resolution experience-specific neuronal populations in the orbitofrontal cortex, a major reward-processing hub thatcontains diverse activity-specific neuronal populations that respond differentially to various aspects of caloric intake8-13 and social stimuli14,15. We coupled genetically encoded activity imaging with thedevelopment and application of methods for optogenetic control of multiple individually defined cells, to both optically monitor and manipulate the activity of many orbitofrontal cortex neurons at the single-cell level in real time during rewarding experiences (caloric consumption and socialinteraction). We identified distinct populations within the orbitofrontal cortex that selectively responded to either caloric rewards or social stimuli, and found that activity of individually specified naturally feeding-responsive neurons was causally linked to increased feeding behaviour; this effect was selective as, by contrast, single-cell resolution activation of naturally social-responsive neurons inhibited feeding, and activation of neurons responsive to neither feeding nor social stimuli did not alter feeding behaviour. These results reveal the presence of potent cellular-level subnetworks within the orbitofrontal cortex that can be precisely engaged to bidirectionally control feeding behaviours subject to, for example, social influences.

    View details for PubMedID 30651638