Posts classified under: Synapses, Cells, and Circuits

Xiangdong William Yang, M.D., Ph.D.

Biography

Dr. X. William Yang is a professor in the Department of Psychiatry & Biobehavioral Sciences at David Geffen School of Medicine at UCLA. He is also a member of the Center for Neurobehavioral Genetics at Semel Institute for Neuroscience & Human Behaviors, and a member of the Brain Research Institute at UCLA. He has served as a regular member at the NIH’s Cell Death in Neurodegeneration (CDIN) Study Section, a Scientific Advisory Board member of the Hereditary Disease Foundation, and a faculty member for Faculty 1000 Medicine?s Neurogenetics Section. William grew up in Tianjin, China. He obtained a combined M.S. and B.S. degrees with summa cum laude from Molecular Biophysics & Biochemistry Department at Yale University in 1991. He received Ph.D. in Molecular Genetics and Neuroscience from Rockefeller University in 1998. During his PhD thesis research with Dr. Nathaniel Heintz, William co-invented (together with Nat Heintz and Peter Model) the first recombineering technology to modify large pieces of DNA called Bacterial Artificial Chromosomes (BACs) and to generate BAC transgenic mice. The BAC transgenic technology is now a widely-used tool to generate transgenic animals for analyses of gene expression and gene function, and for modeling human diseases. After obtaining his Ph.D. degree, William went on to complete his M.D. training from Weill Medical College of Cornell University in 2000, and his Medicine Internship at New York-Presbyterian Hospital in 2001. After a brief postdoctoral training with Nat Heintz at Rockefeller University, William joined UCLA as an Assistant Professor in Dept. of Psychiatry in 2002.

Ranmal Samarasignhe, M.D., Ph.D.

Biography

Dr. Ranmal Samarasinghe received his MD and PhD degrees from the University of Pittsburgh in 2013. He completed his residency in adult neurology at UCLA in 2017 and then completed an NIH funded post-doctoral research and clinical fellowship at UCLA from 2017-2020. During this period, Dr. Samarasinghe obtained clinical training in epilepsy and neurophysiologic intraoperative monitoring. He also performed research developing stem cell-based models of epilepsy and autism, which is the foundation of his own laboratory.

Dr. Samarasinghe’s laboratory seeks to understand the mechanisms of neural network formation and dysfunction in epilepsy and autism. His efforts are focused on 3D brain-like structures called human brain organoids that are grown in a laboratory dish and that are derived from stem cells. Brain organoids can be generated from the stem cells of individual patients and may provide unique insights into the causes of human neurological diseases such as epilepsy and autism. His laboratory is developing and utilizing multiple methodologies including whole-organoid multiphoton based calcium indicator imaging, voltage sensors, traditional extracellular recordings, high throughput genomic screens, and super-resolution synaptic imaging to interrogate the developmental trajectory of nascent neural networks in organoid models. Dr. Samarasinghe will also continue to manage patients with epilepsy and autism in his clinic and perform neurophysiologic intraoperative monitoring for surgical cases performed at UCLA and affiliated hospitals.