Development of an Automatic Pellet Dispenser for Forelimb Grasping Experiments in Rodents

Forelimb grasping experiments are important for investigating the performance of the locomotor system and the learning ability. Due to lack of automatic machines, manual operation is a heavy load for experimenters. Therefore, we developed an automatic pellet dispenser using the Arduino Nano board. The user puts a bucket of food pellets into the storage pool, the machine automatically disperses them and delivers a single pellet to a fixed position in the food plate. When the pellet is taken by the animal, then it delivers another. The system is composed of the Arduino Nano board, a stepper motor, two servo motors, two photo sensors, a display and three buttons. It is inexpensive and easy to use. When tested, it ran orderly and stably. We hope it can help in repetitive experiments, reduce the manual load and save a lot of time.