Education & Certifications
Master of Science, Stanford University, BIOE-MS (2017)
Bachelor of Science, California Institute of Technology, Bioengineering, Business Economics and Management (2015)
Cardiogenic control of affective behavioural state.
Emotional states influence bodily physiology, as exemplified in the top-down process by which anxiety causes faster beating of the heart1-3. However, whether an increased heart rate might itself induce anxiety or fear responses is unclear3-8. Physiological theories of emotion, proposed over a century ago, have considered that in general, there could be an important and even dominant flow of information from the body to the brain9. Here, to formally test this idea, we developed a noninvasive optogenetic pacemaker for precise, cell-type-specific control of cardiac rhythms of up to 900beats per minute in freely moving mice, enabled by a wearable micro-LED harness and the systemic viral delivery of a potent pump-like channelrhodopsin. We found that optically evoked tachycardia potently enhanced anxiety-like behaviour, but crucially only in risky contexts, indicating that both central (brain) and peripheral (body) processes may be involved in the development of emotional states. To identify potential mechanisms, we used whole-brain activity screening and electrophysiology to find brain regions that wereactivated by imposed cardiac rhythms. We identified the posterior insular cortex as a potential mediator of bottom-up cardiac interoceptive processing, and found that optogenetic inhibition of this brain region attenuated the anxiety-like behaviour that was induced by optical cardiac pacing. Together, these findings reveal that cells of both the body and the brain must be considered together to understand the origins of emotional or affective states. More broadly, our results define a generalizable approach for noninvasive, temporally precise functional investigations of joint organism-wide interactions among targeted cells during behaviour.
View details for DOI 10.1038/s41586-023-05748-8
View details for PubMedID 36859543
Deep brain optogenetics without intracranial surgery.
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.
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