Neurally Controlled Computer-simulated Animals: a New Tool for Studying Learning and Memory in Vitro
30th Annual Meeting of the Society for Neuroscience, New Orleans, LA, 2000. Prog. No. 467.20
We have developed the first neurally-controlled animat (simulated animal). It consists of a dissociated rat cortical culture in two-way communication with a computer via 60 electrodes embedded in the culture chamber substrate. Spatio-temporal patterns of activity in the culture are used to control the behavior of an animat situated within a computer-generated virtual reality. Sensory inputs to the animat are fed back to the culture as spatio-temporal electrical stimulus patterns in real time (<100 ms). This short-latency feedback loop in which the network can influence its own stimulation provides a new way to study learning, in vitro. “Learning” is typically defined as a change in behavior resulting from experience. We have given a cultured network a body to behave with and an environment to behave in. Thus, it is now possible to observe the changes in network activity and associated behavior as learning in this new model system. Network properties that subserve learning can be studied with unprecedented detail: We apply 2-photon time-lapse fluorescence microscopy to demonstrate submicron morphological changes on the minutes-to-hours time scale, and high-speed imaging with voltage-sensitive dyes to characterize activity patterns on the millisecond time scale. The neurally-controlled animat will help to bridge the gap between bottom-up (biochemical, cellular) and top-down (behavioral) approaches to the study of learning and memory. http:
www.caltech.edu/~pinelab/PotterGroup.htm.