Current student in the Stanford Neurosciences Interdepartmental Program (IDP).
Honors & Awards
Predoctoral Fellow, Ford Foundation, National Academy of Sciences (2021)
Science and Technology Fellow, United States Coast Guard (2020)
Future Leader in Science, Sanofi Institut Pasteur Award (2017)
U.S. Presidential Champion of Change, The White House, Obama Administration (2016)
Chancellor's Award of Distinction, University of California (2016)
Highest Achievement in Academic Excellence, University of California (2016)
Excellence in Research Distinction, University of California (2016)
Academic Scholarship, Anthem Blue Cross (2014)
Named One of 10 Students Who Will Change the World, University of California (2014)
Endowed Research Award, Bill and Melinda Gates Foundation (2013)
Education & Certifications
B.A., University of California at Irvine, Anthropology (2017)
Current Clinical Interests
- Medical Translational Research
Noninvasive ultrasonic induction of cerebrospinal fluid flow enhances intrathecal drug delivery.
Journal of controlled release : official journal of the Controlled Release Society
Intrathecal drug delivery is routinely used in the treatment and prophylaxis of varied central nervous system conditions, as doing so allows drugs to directly bypass the blood-brain barrier. However, the utility of this route of administration is limited by poor brain and spinal cord parenchymal drug uptake from the cerebrospinal fluid. We demonstrate that a simple noninvasive transcranial ultrasound protocol can significantly increase influx of cerebrospinal fluid into the perivascular spaces of the brain, to enhance the uptake of intrathecally administered drugs. Specifically, we administered small (~1 kDa) and large (~155 kDa) molecule agents into the cisterna magna of rats and then applied low, diagnostic-intensity focused ultrasound in a scanning protocol throughout the brain. Using real-time magnetic resonance imaging and ex vivo histologic analyses, we observed significantly increased uptake of small molecule agents into the brain parenchyma, and of both small and large molecule agents into the perivascular space from the cerebrospinal fluid. Notably, there was no evidence of brain parenchymal damage following this intervention. The low intensity and noninvasive approach of transcranial ultrasound in this protocol underscores the ready path to clinical translation of this technique. In this manner, this protocol can be used to directly bypass the blood-brain barrier for whole-brain delivery of a variety of agents. Additionally, this technique can potentially be used as a means to probe the causal role of the glymphatic system in the variety of disease and physiologic processes to which it has been correlated.
View details for DOI 10.1016/j.jconrel.2022.06.067
View details for PubMedID 35798095
Electrical modulation of transplanted stem cells improves functional recovery in a rodent model of stroke.
2022; 13 (1): 1366
Stroke is a leading cause of long-term disability worldwide, intensifying the need for effective recovery therapies. Stem cells are a promising stroke therapeutic, but creating ideal conditions for treatment is essential. Here we developed a conductive polymer system for stem cell delivery and electrical modulation in animals. Using this system, electrical modulation of human stem cell transplants improve functional stroke recovery in rodents. Increased endogenous stem cell production corresponds with improved function. Transcriptome analysis identified stanniocalcin 2 (STC2) as one of the genes most significantly upregulated by electrical stimulation. Lentiviral upregulation and downregulation of STC2 in the transplanted stem cells demonstrate that this glycoprotein is an essential mediator in the functional improvements seen with electrical modulation. Moreover, intraventricular administration of recombinant STC2 post-stroke confers functional benefits. In summation, our conductive polymer system enables electrical modulation of stem cells as a potential method to improve recovery and identify important therapeutic targets.
View details for DOI 10.1038/s41467-022-29017-w
View details for PubMedID 35292643
Conducting polymer-based granular hydrogels for injectable 3D cell scaffolds.
Advanced materials technologies
2021; 6 (6)
Injectable 3D cell scaffolds possessing both electrical conductivity and native tissue-level softness would provide a platform to leverage electric fields to manipulate stem cell behavior. Granular hydrogels, which combine jamming-induced elasticity with repeatable injectability, are versatile materials to easily encapsulate cells to form injectable 3D niches. In this work, we demonstrate that electrically conductive granular hydrogels can be fabricated via a simple method involving fragmentation of a bulk hydrogel made from the conducting polymer PEDOT:PSS. These granular conductors exhibit excellent shear-thinning and self-healing behavior, as well as record-high electrical conductivity for an injectable 3D scaffold material (~10 S m-1). Their granular microstructure also enables them to easily encapsulate induced pluripotent stem cell (iPSC)-derived neural progenitor cells, which were viable for at least 5 days within the injectable gel matrices. Finally, we demonstrate gel biocompatibility with minimal observed inflammatory response when injected into a rodent brain.
View details for DOI 10.1002/admt.202100162
View details for PubMedID 34179344
View details for PubMedCentralID PMC8225239
Overnight Caloric Restriction Prior to Cardiac Arrest and Resuscitation Leads to Improved Survival and Neurological Outcome in a Rodent Model.
Frontiers in neuroscience
2020; 14: 609670
While interest toward caloric restriction (CR) in various models of brain injury has increased in recent decades, studies have predominantly focused on the benefits of chronic or intermittent CR. The effects of ultra-short, including overnight, CR on acute ischemic brain injury are not well studied. Here, we show that overnight caloric restriction (75% over 14 h) prior to asphyxial cardiac arrest and resuscitation (CA) improves survival and neurological recovery as measured by, behavioral testing on neurological deficit scores, faster recovery of quantitative electroencephalography (EEG) burst suppression ratio, and complete prevention of neurodegeneration in multiple regions of the brain. We also show that overnight CR normalizes stress-induced hyperglycemia, while significantly decreasing insulin and glucagon production and increasing corticosterone and ketone body production. The benefits seen with ultra-short CR appear independent of Sirtuin 1 (SIRT-1) and brain-derived neurotrophic factor (BDNF) expression, which have been strongly linked to neuroprotective benefits seen in chronic CR. Mechanisms underlying neuroprotective effects remain to be defined, and may reveal targets for providing protection pre-CA or therapeutic interventions post-CA. These findings are also of high importance to basic sciences research as we demonstrate that minor, often-overlooked alterations to pre-experimental dietary procedures can significantly affect results, and by extension, research homogeneity and reproducibility, especially in acute ischemic brain injury models.
View details for DOI 10.3389/fnins.2020.609670
View details for PubMedID 33510613
View details for PubMedCentralID PMC7835645
Adolescent Vulnerability to Heightened Emotional Reactivity and Anxiety After Brief Exposure to an Obesogenic Diet.
Frontiers in neuroscience
2020; 14: 562
Background: Emerging evidence demonstrates that diet-induced obesity disrupts corticolimbic circuits underlying emotional regulation. Studies directed at understanding how obesity alters brain and behavior are easily confounded by a myriad of complications related to obesity. This study investigated the early neurobiological stress response triggered by an obesogenic diet. Furthermore, this study directly determined the combined impact of a short-term obesogenic diet and adolescence on critical behavioral and molecular substrates implicated in emotion regulation and stress.Methods: Adolescent (postnatal day 31) or adult (postnatal day 81) Lewis rats were fed for 1 week with an experimental Western-like high-saturated fat diet (WD, 41% kcal from fat) or a matched control diet (CD, 13% kcal from fat). We used the acoustic fear-potentiated startle (FPS) paradigm to determine the effects of the WD on cued fear conditioning and fear extinction. We used c-Fos mapping to determine the functional influence of the diet and stress on corticolimbic circuits.Results: We report that 1-week WD consumption was sufficient to induce fear extinction deficits in adolescent rats, but not in adult rats. We identify fear-induced alterations in corticolimbic neuronal activation and demonstrate increased prefrontal cortex CRHR1 messenger RNA (mRNA) levels in the rats that consumed the WD.Conclusion: Our findings demonstrate that short-term consumption of an obesogenic diet during adolescence heightens behavioral and molecular vulnerabilities associated with risk for anxiety and stress-related disorders. Given that fear extinction promotes resilience and that fear extinction principles are the foundation of psychological treatments for posttraumatic stress disorder (PTSD), understanding how obesogenic environments interact with the adolescent period to affect the acquisition and expression of fear extinction memories is of tremendous clinical relevance.
View details for DOI 10.3389/fnins.2020.00562
View details for PubMedID 32694970
Recovery from Coma Post-Cardiac Arrest Is Dependent on the Orexin Pathway
JOURNAL OF NEUROTRAUMA
2017; 34 (19): 2823–32
Cardiac arrest (CA) affects >550,000 people annually in the United States whereas 80-90% of survivors suffer from a comatose state. Arousal from coma is critical for recovery, but mechanisms of arousal are undefined. Orexin-A, a hypothalamic excitatory neuropeptide, has been linked to arousal deficits in various brain injuries. We investigated the orexinergic system's role in recovery from CA-related neurological impairments, including arousal deficits. Using an asphyxial CA and resuscitation model in rats, we examine neurological recovery post-resuscitation in conjunction with changes in orexin-A levels in cerebrospinal fluid (CSF) and orexin-expressing neurons. We also conduct pharmacological inhibition of orexin post-resuscitation. We show that recovery from neurological deficits begins between 4 and 24 h post-resuscitation, with additional recovery by 72 h post-resuscitation. Orexin-A levels in the CSF are lowest during periods of poorest arousal post-resuscitation (4 h) and recover to control levels by 24 h. Immunostaining revealed that the number of orexin-A immunoreactive neurons declined at 4 h post-resuscitation, but increased to near normal levels by 24 h. There were no significant changes in the number of neurons expressing melanin-concentrating hormone, another neuropeptide localized in similar hypothalamus regions. Last, administration of the dual orexin receptor antagonist, suvorexant, during the initial 24 h post-resuscitation, led to sustained neurological deficits. The orexin pathway is critical during early phases of neurological recovery post-CA. Blocking this early action leads to persistent neurological deficits. This is of considerable clinical interest given that suvorexant recently received U.S. Food and Drug Administration approval for insomnia treatment.
View details for DOI 10.1089/neu.2016.4852
View details for Web of Science ID 000411672700016
View details for PubMedID 28447885
View details for PubMedCentralID PMC5647501