Figure 5. Three-dimensional multi-site random access photostimulation (3D-MAP) is able to stimulate multiple targets simultaneously to explore network dynamics.
(A) Schematic diagram of the experiment. The stimulation ROIs are known to have synaptic connections with the patched interneuron from the widefield mapping as described in Figure 4. (B) The positions of the five ROIs are identified in Figure 4E. (C) Representative photocurrent traces for simultaneous stimulation of subsets of the five ROIs. Traces are averaged over four repetitions. The number(s) above each trace indicate the ROIs that were stimulated to generate the response. (D) Comparison of the actual synaptic response by simultaneous stimulation of ROIs 1–5 (blue) to the response calculated by linearly summing the traces when stimulating ROIs 1–5 individually (red). The individual response from each ROI is shown in the first row of C. (E) Comparison of the integral of the synaptic currents from simultaneous stimulation of multiple connected presynaptic neurons (blue) to the linear sum of the individual stimulation responses (red). The mean and standard deviation of data is calculated from all the k-combinations (number of foci) from the given set of five targets. The sample size is .