Round two of the Arduino-based experimental control unit! In addition to the features of the original unit (visual stimuli, TTL trigger to begin trial, etc), this version will monitor animal behavior with a lickometer (i.e., detect when the animal licks on a spout) and deliver liquid reward when some requirement is fulfilled. For example, in order to receive a reward, the animal waits for a visual cue and then licks four times within a one second window.
Like the first unit, this version will be used in conjunction with 2-photon imaging to visualize large ensemble neural activity in awake animals. With the addition of behavioral input, we will be able to see how behavioral conditioning changes activity in the brain.
So far, I’ve tested each component and made sure the power supply provides enough juice. Here is the initial layout of the circuit that I will eventually cram into a plastic housing: