The effects of the current stimulation on electrical activity in dissociated neurons

Rat hippocampal neurons were cultured on a dish with 64 micro planer electrodes. We found that the silent and reproducible period lasting for 1 sec immediately after the activity evoked in advance. In addition, the repetitive stimuli suppress the spontaneously occurring bursting activity in frequency. These results suggest that distinct internal state of the neuronal circuit was triggered by an electrical stimulation, and these dynamics of network activity may contribute to information processing. In previous study, we developed the neuro-robot system in which the neurons were connected to a robot body and interacted with external world. By utilizing the dynamics of a living neuronal network, it can be designed that, so to speak, the robot, which behaves according to the history of the sensor inputs which the neuronal network has memorized. We are verifying whether the dynamics intrinsic in a neural network can contribute to the action determination of a creature, by moving such a model system.