How Should We Think About Bursts?

Population bursts of action potentials are the most prominent feature of activity recorded from mam-malian neuronal networks grown on MEAs. In the intact brain or spinal cord, they are considered variously as motor patterns, sensory gates, sleep spindles, UP-states, developmental signals, epileptiform activity, or memories. I prefer to remain agnostic about what bursts " mean " in vitro, and to study them in whatever way suits the purpose at hand. In this talk, I summarize MEA work from my lab over the past decade, focusing on our continually changing perspectives on bursts, as new results and methods arrive. Our overarching goal is to use MEAs and optics to study the basics of learning, memory, and information processing. Cultured networks are more easily accessed, imaged, controlled, and manipulated (physically, chemically, electrically, optically) than are any animal models, but it is important to keep in mind their many limitations and simplifications. To bring them closer to animal models, we developed the idea of embodying cultured networks, so they could interact with the world, express behavior and receive sensory input. 1,2 We developed ways to control bursting, and have recently verified that by doing so, one can more reliably study learning in vitro.