Figure 2

Imaging axonal morphology and recording its extracellular activity at 10 DIV. (A) Two reservoir modules (somal compartments, bottom) and microchannels with axonal projections. Axons are passing the neurite filtering region before reaching the microchannel entrance. Two electrodes are recording from each reservoir module. Five subsequent electrodes recorded from each microchannel. (B) Magnified view of one reservoir module and its dendrite buffer region (lower green rectangle in A). (C) Magnified view of counterpart compartment with exiting axons (upper yellow frame in A). (D) Long-term window of axonal activity (1 s) from subsequent electrodes of a wide (green circles in A and green signals in D) and narrow (blue circles in A and blue signals in D) microchannels. The dashed-rectangles (60 ms) zoom onto the propagating action potentials in a wide and a narrow microchannel (green and blue, respectively). Each panel shows different propagation velocities. The whole culture morphology at 10 DIV including all 8 modules is shown in Suppl. Fig. 2. Electrode pitch: 200 µm.