Abstract: Provided herein is a stimulation and measurement device. The stimulation and measurement device includes a microwell plate having a top side, a bottom side, and at least one well extending from the top side towards the bottom side; a first assembly removably positioned on the top side of the microwell plate; a second assembly removably positioned on the bottom side of the microwell plate; and a microcontroller. The first assembly includes a first printed circuit board having at least one pair of stimulating light emitting diodes (LEDs) positioned thereon to align with one of the wells. The second assembly includes a second printed circuit board having at least one photodiode positioned thereon to align with one of the pairs of stimulating LEDs, and at least one excitation LED paired with each of the photodiodes. The microcontroller is configured to control the stimulating LED(s), the photodiode(s), and the excitation LED(s).