Single Neurons and Networks in Human Cortical Activity

Almost 100 years ago the EEG was being developed as a new tool for understanding the brain in both health and disease. Early on, Hans Berger and others recognized the importance of oscillatory activity in the EEG; characterizing alpha, delta, theta waves and particular graphoelements such as sleep spindles and K complexes. Quickly, the clinical utility in capturing seizures became apparent. Despite substantial investigations into these events, much is still not known about the neural mechanisms underlying these phenomena or their role in cognition and pathological brain activity. While still using basic EEG approaches, we have studied these events using a multi-modal, multiscale approach in humans which leverages novel neurotechnologies and clinical intracranial recordings to examine neural activity from the level of single neurons to network interactions. A synthesis of these techniques can be used to create a multi-scale model of the underlying activity which links individual neuronal activity to large-scale network interactions. In this presentation, I will discuss some of these technologies including thin-film microgrids and Neuropixels and findings from studies using these tools as they relate to the pathophysiology of epilepsy, normal oscillations and cognitive processes including language and memory consolidation during sleep. The aggregate of these investigations provide new insights, or at least new hypotheses, about the overall architecture of neuronal interactions in the human brain in both health and disease. 

Speaker Bio

Dr. Sydney Cash, MD, PhD is Professor of Neurology at Harvard Medical School and attending epileptologist at Massachusetts General Hospital. Dr. Cash received his BS in Biology from Yale College before going on to pursue an MD and PhD at Columbia University. Following internship and residency in Neurology at Brigham and Women’s Hospital and Massachusetts General Hospital, Dr. Cash completed a fellowship in epilepsy and neurophysiology at Massachusetts General Hospital. Dr. Cash's research focuses on understanding the mechanisms underlying both normal and pathological cortical activity and developing novel neuroprosthetic approaches for treating a wide variety of neurological problems. This work, funded by NIH, DOD, NSF and foundation grants, has melded issues spanning basic neuroscientific questions of the physiology that underlie normal oscillatory activity, sleep and cognition, to issues surrounding how the brain transitions from one state to another including from normal activity to seizure activity and how seizures can be localized and treated.