title: Design and construction of a low-cost nose poke system for rodents.
abstract: Operant behavioral tasks for animals have long been used to probe the function of multiple brain regions (i.e., understanding the role of dopamine in electrical brain stimulation reward [1], or determining the rewarding properties of feeding oriented brain pathways [2]). The recent development of tools and techniques has opened the door to refine the answer to these same questions with a much higher degree of specificity and accuracy, both in biological and spatial-temporal terms [3], [4]. A variety of systems designed to test operant behavior are now commercially available, but have prohibitive costs. Here, we provide a low-cost alternative to a nose poke system for mice. Adapting a freely available sketch for ARDUINO boards, in combination with an in-house built PVC box and inexpensive electronic material we constructed a four-port nose poke system that detects and counts port entries. To verify the applicability and validity of our system we tested the behavior of DAT-CRE transgenic mice injected with an adeno-associated virus to express ChannelRhodopsin 2 in the Ventral tegmental area (VTA) and used the BNC output to drive a blue laser coupled to a fiber implanted above the VTA. Over 6 days, mice perform as it has been reported previously [5] exhibiting a remarkable preference for the port that triggers optogenetic stimulation of VTA dopamine neurons. •We provide a low cost alternative to commercially available nose poke system.•Our custom made apparatus is open source and TTL compatible.•We validate our system with optogenetic self-stimulation of dopamine neurons.
authors.affiliation: Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Rizzi
authors.affiliation: Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
authors.forename: Meredith E
authors.initials: ME
authors.lastname: Lodge
authors.affiliation: Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Tan
keywords: Arduino based nose poke system for rodents; Lowcost; Nose poke; Operant behavior; Optogenetics; Reward; Rodent