Feeding Experimentation Device version 3 (FED3): An open-source home-cage compatible device for measuring food intake and operant behavior
Curation statements for this article:-
Curated by eLife
Evaluation Summary:
All three reviewers were very enthusiastic about this manuscript describing FED3, a new and improved open-source option for a home cage pellet dispensing device. They all agreed that this open-source tool would be of wide-interest to neuroscience laboratories, that the manuscript was well-written and clear, and that the cross-lab validation was informative. They also appreciated that this Tools & Resource manuscript all necessary open-source hardware, firmware, visualization code, and Arduino and Python libraries for user customization of experiments and analysis. Minor concerns were identified with the extent to which the manuscript describes and compares to existing systems and with clarity on some details of the system.
(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #3 agreed to share their name with the authors.)
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Abstract
Feeding is critical for survival and disruption in the mechanisms that govern food intake underlie disorders such as obesity and anorexia nervosa. It is important to understand both food intake and food motivation to reveal mechanisms underlying feeding disorders. Operant behavioral testing can be used to measure the motivational component to feeding, but most food intake monitoring systems do not measure operant behavior. Here, we present a new solution for monitoring both food intake and motivation: The Feeding Experimentation Device version 3 (FED3). FED3 measures food intake and operant behavior in rodent home-cages, enabling longitudinal studies of feeding behavior with minimal experimenter intervention. It has a programmable output for synchronizing behavior with optogenetic stimulation or neural recordings. Finally, FED3 design files are open-source and freely available, allowing researchers to modify FED3 to suit their needs. In this paper we demonstrate the utility of FED3 in a range of experimental paradigms.
In Brief
Using a novel, high-throughput home cage feeding platform, FED3, Matikainen-Ankney et al. quantify food intake and operant learning in groups of mice conducted at multiple institutions across the globe. Results include rates of operant efficiency, circadian feeding patterns, and operant optogenetic self-stimulation.
Highlights
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The Feeding Experimentation Device version 3(FED3) records food intake and operant behavior in rodent home cages.
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Analysis of food intake includes total intake, meal pattern analysis, and circadian analysis of feeding patterns.
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FED3 also allows for operant behavioral assays to examine food learning and motivation.
Article activity feed
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Reviewer #3 (Public Review):
Bridget A. Matikainen-Ankney et al. discuss the newest generation of their open-source Feeding Experimentation Device (FED3) platform capable of detailed tracking of food pellet intake and dual nose-poke operant behavioral testing. This platform provides a complete solution for these types of studies and includes all necessary open-source hardware, firmware, visualization code, and Arduino and Python libraries for user customization of experiments and analysis. FED3 has a rechargeable battery life of around one week and can operate without any external wires, logging data onto an on-board SD card and allowing for flexible placement in a rodent's home-cage. The platform also includes an on-board display for showing current experimental parameters/data and a variable voltage digital output for synchronizing …
Reviewer #3 (Public Review):
Bridget A. Matikainen-Ankney et al. discuss the newest generation of their open-source Feeding Experimentation Device (FED3) platform capable of detailed tracking of food pellet intake and dual nose-poke operant behavioral testing. This platform provides a complete solution for these types of studies and includes all necessary open-source hardware, firmware, visualization code, and Arduino and Python libraries for user customization of experiments and analysis. FED3 has a rechargeable battery life of around one week and can operate without any external wires, logging data onto an on-board SD card and allowing for flexible placement in a rodent's home-cage. The platform also includes an on-board display for showing current experimental parameters/data and a variable voltage digital output for synchronizing the system with other external devices such as an optogenetic simulation system. The authors show multiple applications of the FED3 platform including detailed food intake tracking, fixed-ratio operant behavior experiments, and optogenetic self-stimulation. Importantly, they also highlight the ability to do studies across multiple, remote laboratories by leveraging the standardization of such a food intake platform.
Strengths:
The FED3 platform is well thought out and clearly builds off the authors' experience designing and working with their previous generation systems. The specific open-source approach taken by the authors include, not just openly providing design files but, building an understandable and open ecosystem of tools and libraries for laboratories to customize the platform to fit a broad range of experiments. By including data visualization tools and a Python library for working with FED3 data, the authors effectively lower the technical entry point for using such a platform and streamline the process of implanting the system in one's own experiments. The paper provides strong evidence of the FED3's capabilities and relevance of data generated across a range of use cases. There is compelling evidence of the usefulness of developing an open standard for food intake tracking, allowing for multi-site studies and across-laboratory comparisons. Finally, the system is significantly more affordable than other commercial options, lowering the economic barrier for implementing food intake tracking and operant behavior experiments.
Weaknesses:
While this paper presents a very useful, customizable, and flexible approach to food intake and operant behavior studies, certain aspects of the device could be better described in the paper. This is only a minor weakness as all hardware and code is openly available online, allowing for a more detailed understanding of the system beyond what is presented in the paper. It would be helpful to identify the major electronics components on the custom printed circuit board to aid in customization of the system. It would also be useful to provide more details as to the mechanical mechanism used to deliver food pellets and the optical beam breaks for detecting nose-pokes and food pellets.
Some potential limitations of the system include the inability to detect food pellet hoarding, lack of wireless option to access and configure the system, limited battery life, complications when using granular bedding, and no way to identify individual mice. The authors identify and discuss these limitations within the paper which is appreciated.
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Reviewer #2 (Public Review):
"Feeding Experimentation Device version 3 (FED3): An open-source device for measuring food intake and operant behavior" describes the third iteration of an open-source automatic feeding device to be used with mice. I have no concerns about this paper and would recommend it as is. The authors have provided an incredible resource for the fields of feeding and reward-related behaviors, and provide all the details needed for assembly and use. Moreover, the data that they have collected using this device constitutes an advance, particularly the circadian rhythms of feeding, as well as the increase in operant responding during the light cycle. This device enables homecage measurement of feeding and training for motivational behavior, enabling most any laboratory to examine feeding behaviors in their experiments.
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Reviewer #1 (Public Review):
In this manuscript the authors present a new and improved open-source option for a home cage pellet dispensing device that carries with it the ability to offer continuous monitoring of feeding behavior as well home-cage operant testing. This device solves many issues in the way individuals typically go about studying animal feeding behavior including but not limited to testing at only certain times of the day for limited amounts of time and food restriction in a manner that optimizes cost, functionality, scalability, and customizability over traditional or commercial options. Of note, besides offering the ability to capture massive amounts of home cage feeding and operant data directly in the vivarium of animal housing facilities, a major strength of this approach is that the authors demonstrate that the …
Reviewer #1 (Public Review):
In this manuscript the authors present a new and improved open-source option for a home cage pellet dispensing device that carries with it the ability to offer continuous monitoring of feeding behavior as well home-cage operant testing. This device solves many issues in the way individuals typically go about studying animal feeding behavior including but not limited to testing at only certain times of the day for limited amounts of time and food restriction in a manner that optimizes cost, functionality, scalability, and customizability over traditional or commercial options. Of note, besides offering the ability to capture massive amounts of home cage feeding and operant data directly in the vivarium of animal housing facilities, a major strength of this approach is that the authors demonstrate that the same amount of learning that would typically require 16 days (one-hour testing sessions) can be accomplished overnight (and with interesting circadian effects on decision-making that are often overlooked). The authors demonstrate useability of this device across institutions in other labs and integration with optogenetics (as well as citing recent studies integrating the device with recording systems).
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Evaluation Summary:
All three reviewers were very enthusiastic about this manuscript describing FED3, a new and improved open-source option for a home cage pellet dispensing device. They all agreed that this open-source tool would be of wide-interest to neuroscience laboratories, that the manuscript was well-written and clear, and that the cross-lab validation was informative. They also appreciated that this Tools & Resource manuscript all necessary open-source hardware, firmware, visualization code, and Arduino and Python libraries for user customization of experiments and analysis. Minor concerns were identified with the extent to which the manuscript describes and compares to existing systems and with clarity on some details of the system.
(This preprint has been reviewed by eLife. We include the public reviews from the reviewers …
Evaluation Summary:
All three reviewers were very enthusiastic about this manuscript describing FED3, a new and improved open-source option for a home cage pellet dispensing device. They all agreed that this open-source tool would be of wide-interest to neuroscience laboratories, that the manuscript was well-written and clear, and that the cross-lab validation was informative. They also appreciated that this Tools & Resource manuscript all necessary open-source hardware, firmware, visualization code, and Arduino and Python libraries for user customization of experiments and analysis. Minor concerns were identified with the extent to which the manuscript describes and compares to existing systems and with clarity on some details of the system.
(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #3 agreed to share their name with the authors.)
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