Trisynaptic-circuit Hippocampus (IMAGE) Max-Planck-Gesellschaft Caption This is a schematic diagram of the trisynaptic circuit of the hippocampus (red) and the position of the stimulation electrode. Neuronal activity was measured using fluorescent dyes that react to changes in voltage and a fluorescence microscope. Microelectrodes in the CA1 and CA3 region record the electrical signals. Credit MPI of Psychiatry Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.