Meet the Halpern-Malenka Lab Members

Dr. Casey Halpern

Casey H. Halpern, MD, is Assistant Professor of Neurosurgery and, by courtesy, of Neurology and Neurological Sciences, and Psychiatry and Behavioral Sciences at Stanford University Medical Center. Dr. Halpern received his medical degree from the University of Pennsylvania School of Medicine. He completed his residency in Neurological Surgery and a fellowship in Stereotactic and Functional Neurosurgery at the University of Pennsylvania. He focuses on the surgical treatment of movement disorders and epilepsy and has particular interest in minimally invasive surgical approaches, as well as neurostimulation procedures.

Dr. Hemmings Wu

Dr. Wu's long term research interests lie in the field of neuromodulation for psychiatric indications, specifically mechanistic neurophysiology and closed-loop deep brain stimulation, to improve current neuromodulation therapies for mental disorders. He received his early education in the U.S. and Taiwan, and received his medical bachelor degree (MBBS) in Peking University Health Science Center, master degree in surgery (neurosurgery, MMed) in Shanghai Jiaotong University School of Medicine, and PhD in neuroscience in KU Leuven, Leuven, Belgium. His clinical and academic training, and research experience have provided him with an excellent background in multiple biological disciplines including neurosurgery, psychiatry, and neuroelectrophysiology. His research focus during PhD years at KU Leuven was deep brain stimulation and recording in the basal ganglia in animal models and clinical trials (mainly in obsessive-compulsive disorder and anorexia nervosa), with a strong orientation toward achieving closed-loop deep brain stimulation. He is currently a first-year postdoctoral research fellow at Stanford University, under the supervision of Dr. Casey Halpern and Robert Malenka.

Dr. Daniel Christoffel

Daniel Christoffel, PhD, is a postdoctoral fellow in the Department of Neurosurgery. He is currently investigating specific circuits involved in reward and consummatory behaviors. Through synapse-specific modulation, he hopes to uncover how various glutamatergic inputs to the nucleus accumbens regulate behaviors involved in reward seeking.

His long-term goals involve understandinf the distinct modes of plasticity present in different synaptic types, how these mechanisms encode experience to regulate behavior, and uncover what role they play in psychiatric disorders.

Dr. Kai Miller

Kai Miller, MD, PhD is currently undergoing residency training in Neurosurgery, with particular emphasis on 1) functional and stereotactic surgical approaches, 2) eloquent cortex tumors and awake craniotomies, and 3) epilepsy. As a resident, he is continuing ongoing research aimed at understanding the dynamics of cognition, behavior, and plasticity. He plans to pursue a career as a physician-scientist, with a robust clinical practice and a research lab where cutting-edge developments insight into large-scale brain dynamics can be translated into the surgical environment. He plans to develop closed-loop cortical devices for disease therapeutics, neural plasticity, and brain-computer interfacing. Additionally, he intends to create novel diagnostic and surgical techniques to spare eloquent brain regions and encourage reorganization after tumor resection. 


Dr. Allen Ho

Allen was born and raised in Irvine, California. He completed his undergraduate training at University of California, San Diego as part of the combined-degree Medical Scholars Program with a major in Economics. He then left California to attend Harvard Medical School where he earned his MD in 2014. His research interests include expanding indications for deep brain stimulation and neuromodulation, technology-driven minimally-invasive approaches to cranial and spinal neurosurgery, and quality improvement initiatives within clinical neurosurgery. In the Halpern Lab, Allen is utilizing advanced functional imaging (fMRI, DTI) to study the effects of functional neurosurgery and exploring the role of neuromodulation in addiction, OCD, and obesity in both animal models and humans. Allen is also an avid traveler and foodie, and enjoys playing and watching basketball in his free time.

Dr. Jonathan Parker

Jonathon Parker, MD, PhD, grew up in Portland, Oregon and Southwest Washington. He completed his undergraduate training in Biology at Dartmouth College, where he discovered a passion for medicine and biomedical research, completing an honor’s thesis investigating the transcriptional regulation of the cell cycle. Moving west, Jonathon then completed both his M.D. and Ph.D. training in the Medical Scientist Training Program (MSTP) at the University of Colorado in Denver. Under the mentorship of neurosurgeon, Dr. Allen Waziri, Jonathon’s research focused on developing techniques for real-time imaging of glioblastoma tumor invasion to discover clinically targetable pathways. Outside of the hospital, Jonathon enjoys spending time with his wife and pets, exploring new cities, cooking, collecting antique photos, fly-fishing, and hiking.

Dr. Stanley Hoang

Stan received both of his undergraduate degree in Human Biology and his medical degree from Stanford. During medical school, Stan pursued an HHMI fellowship researching the mechanisms of functional recovery following ischemic stroke in Dr. Gary Steinberg's lab. His current research interest focuses on the use of neural stem cells in the restoration of CNS function. Stan plans to pursue an academic career with a likely focus on vascular or tumor neurosurgery.

William Connors

William is an undergraduate student at Stanford University and a research assistant in the Halpern-Malenka Lab.

Karen Lee

Karen Lee is a fourth year undergraduate at Stanford pursuing a bachelor’s degree in biology with honors in neurobiology. Having worked on elucidating the molecular mechanisms of tumor metastasis in glioblastoma, she is excited now to take her interest in neuropsychiatric disorders to a more translational setting. In the Halpern lab, she hopes to help identify a robust neural biomarker using a mouse model of behavioral disinhibition in order to achieve a closed loop DBS system. The goal or her work is to bring a closed loop DBS system to current DBS patients for more adaptive, on demand treatments for psychiatric disorders. Outside of the lab, she is passionate about science and health education for preadolescents, as well as promoting the intersection of biotechnology and medicine within the Stanford community.   

Vinod Ravikumar    

Vinod Ravikumar is currently a third-year medical student interested in investigating neurological and psychiatric disorders. Specifically, he is working to uncover circuits involved in consumption and reward behaviors, and applying Deep Brain Stimulation neurosurgery in order to modulate them. Vinod graduated with honors from Washington University in St. Louis with a B.S. in Biomedical Engineering and has extensive knowledge of Cardiovascular Engineering from his time in the lab of Dr. Igor Efimov, Chair of the Department of Biomedical Engineering at George Washington University.