A Do-it-yourself System for Scheduled Feeding of Laboratory Rodents in Their Home Cage

Intermittent fasting and research surrounding the influence of timed caloric restriction on body weight regulation and aging outcomes are trending, both in society and in the laboratory. To study time-restricted feeding and/or caloric restriction in the laboratory, allotted quantities of food are dispersed at scheduled time intervals. Current technology for scheduled feeding of rodents involves either specialized cages with gated food entry ports, time-locked digital hoppers, or manual food delivery. Specialized equipment for such experiments can be costly and manual feeding often requires investigators to come in for late night/early morning time points, precluding prolonged studies. The automated feeding system described here provides a cost-effective tool for timed feeding and/or caloric restriction that can be implemented on standard rodent cages with minimal modifications. The protocol uses an off-the-shelf autofeeder that is outfitted to a standard microisolator cage lid (mouse, hamster, rat, or guinea pig cage lids) and can administer the desired food allotments at programmed time intervals in the animal's home cage. Our design can be modified to accept various feeders or slight variations in cage dimensions. We provide the design, assembly, and protocol for the feeding system along with an alternative lid and cage modification for tethered optogenetic or fiber photometry experiments.