•Animalscanbechronicallyinstrumentedandusedsequentiallyastheirowncontrolorinmultiplestudiestoreducethenumberofanimals.•Stressartifactinducedbyhandlingisavoided.•Physiologicmeasurementscanbeobtainedaroundtheclockwithnolabpersonnelpresent.•Decreasesthecostsofmanyprotocolsbyreducingthenumberofanimalsandmaintenancerequired.