Figure 2.

NeuroRighter’s StimSrv subsystem. (A) To deliver complex, non-periodic stimuli, NeuroRighter uses a double-buffering system. This allows samples to be generated and written to the NI cards’ analog and digital outputs simultaneously. At a given instant, one buffer is reserved for reading (pink) and one from writing (gray). When the all samples in the read buffer are generated, the buffers switch roles, allowing seamless delivery of constantly varying stimulus patterns and generic analog and digital signals. When using StimSrv for closed-loop protocols, the loop() function is called at the instant of a buffer switch. (B) Example open-loop stimulus protocol using StimSrv. (i) 100, 1 s Poisson sequences of electrical stimuli (left) and a single repeated Poisson sequence (right), were delivered to a dissociated cortical network (biphasic, voltage controlled, ±0.75V, 800 μs period). Stimulus rasters are shown using a gray-scale to indicate the trial number. For repeated stimuli, stimulus points are overlaid since stimulus delivery is clock-synchronized with the acquisition subsystem. (ii) Rastergrams of 4 units are shown below each stimulus raster, across trials. Example waveforms for each of the 4 units are shown to the right.