Figure 1.

Schematic of the closed-loop neural recording setup for sleep/wake response tracking

Video recording, stimulation, and LED illumination are controlled using an Arduino microcontroller. Chemical stimulation through the microfluidic arena switches between stimulus (S) and buffer (B) solutions via control fluid flow (C). Brightfield images are used to track sleep behavior and fluorescent images are used to measure GCaMP calcium transients in neurons. Image capture, sleep/wake state determination, and chemical stimulation are controlled by a computer in a closed loop, without user intervention.