From the Kravitz lab at the NIH comes a simple device for dispensing pre-measured quantities of food at regular intervals throughout the day. Affectionately known as “SnackClock”, this device uses a 24-hour clock movement to rotate a dispenser wheel one revolution per day. The wheel contains 12 compartments, which allows the device to dispense 12 pre-measured “snacks” at regular 2 hour intervals. The Kravitz lab has used this device to dispense high-fat diet throughout the day, rather than giving mice one big piece once per day. The device is very simple to build and use, requiring just two 3D printed parts and a ~$10 clock movement. There is no microcontroller or coding required for this device, and it runs on one AA battery for >1 year. The 3D files are supplied and can be edited to fit SnackClock in different brands of caging, or to adjust the number of snack compartments. With additional effort the clock movement could be replaced by a stepper motor to allow for dispensing at irregular or less frequent intervals.
An open-source, Arduino-controlled syringe pump delivers small, accurate amounts of liquid. The basic menu allows users to select bolus size, and Arduino can be easily customized for a variety of projects. The pump uses 3D-printed parts and easily obtainable hardware.
Lucy Palmer and Andrew Micallef, of the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia, have shared the following Arduino and Python based platform for Go/ No-Go tasks in an article published by Frontiers in Cellular Neuroscience.
The Go/No-Go sensory task requires an animal to report a decision in response to a stimulus. In “Go” trials, the subject must respond to a target stimulus with an action, while in “No-Go” trials, the subject withholds a response. To execute this task, a behavioral platform was created which consists of three main components: 1) a water reward delivery system, 2) a lick sensor, and 3) a sensory stimulation apparatus. The water reward is administered by a gravity flow water system, controlled by a solenoid pinch valve, while licking is monitored by a custom-made piezo-based sensor. An Arduino Uno Rev3 simultaneously controls stimulus and reward delivery. In addition, the Arduino records lick frequency and timing through the piezo sensor. A Python script, employing the pyserial library, aids communication between the Arduino and a host computer.
In Frontiers Neuroscience, Tyler Libey and Eberhard E. Fetz share their open-source device for recording neural activity from free behaving non-human primates in their home cages and administering reward.
This device is designed to document bodily movement and neural activity and deliver rewards to monkeys behaving freely in their home cages. This device allows researchers to explore behaviors in freely moving non-human primates rather than simply relying on rigid and tightly controlled movements which lends itself to further understanding movement, reward, and the neural signals involved with these behaviors. Studying free-moving animals may offer essential insight to understanding the neural signals associated with reward-guided movement, which may offer guidance in developing more accurate brain machine interfaces. The behavior monitoring system incorporates existing untethered recording equipment, Neurochip, and a custom hub to control a cage-mounted feeder to deliver short-latency rewards. A depth camera is used to provide gross movement data streams from the home cage in addition to the neural activity that is recorded.
Jesús Ballesteros, Ph.D. (Learning and Memory Research Group, Department of Neurophysiology at Ruhr-University Bochum, Germany) has generously his project, called Autoreward2, with OpenBehavior. Autoreward2 is an Elegoo Uno-based system designed to detect and reward rodents in a modified T-maze task.
In designing their modified T-maze, Ballesteros found the need for an automatic reward delivery system. Using open-source resources, he aimed to create a system with the following capabilities:
Detect an animal at a certain point in a maze;
Deliver a certain amount of fluid through the desired licking port;
Provide visual cues that indicate which point in the maze has been reached;
Allow different modes to be easily selected using an interface;
Allow different working protocols (i.e., habituation, training, experimental, cleaning)
To achieve these aims, he created used an Elegoo UNO
R3 board to read inexpensive infrared emitters. Breaking any infrared beam causes the board to open one or two solenoid valves connected to a fluid tank. The valve remains open for around 75 milliseconds, allowing a single drop of fluid to form at the tip of the licking port. Additionally, the bread board contains LEDS to signal to the researcher when the IR beam has been crossed.
Currently, a membrane keypad allows different protocols or modes to be selected. The system is powered through a 9V wall adapter, providing 3.3V to the LEDs and IR circuits and 9V to the solenoids.
Importantly, the entire system can be built for under 80€. In the future, Ballesteros hopes to add a screen and an SD card port, and to switch the keypad out for a wireless interface.
Alexxai Kravitz has generously shared the following regarding FED, part 2:
The Feeding Experimentation Device (FED) is a free, open-source system for measuring food intake in rodents. FED uses an Arduino processor, a stepper motor, an infrared beam detector, and an SD card to record time-stamps of 20mg pellets eaten by singly housed rodents. FED is powered by a battery, which allows it to be placed in colony caging or within other experimental equipment. The battery lasts ~5 days on a charge, providing uninterrupted feeding records over this duration. The electronics for building each FED cost around $150USD, and the 3D printed parts cost between $20 and $400, depending on access to 3D printers and desired print quality.
The Kravitz lab has published a large update of their Feeding Experimentation Device (FED) to their Github site, including updated 3D design files that print more easily and updates to the code to dispense pellets more reliably.
In their 2014 paper “Open-Source Syringe Pump Library,” Bas Wijnen, Emily Hunt, Gerald Anzalone, and Joshua Pearce detail an open-source syringe pump apparatus developed in their lab, as well as, validate the performance of the device. The authors write, “This syringe pump was designed using freely available open-source computer aided design (CAD) software and manufactured using an open-source RepRap 3-D printer and readily available parts. The design, bill of materials and assembly instructions are globally available to anyone wishing to use them on the Open-source syringe pump Approdepia page… The cost of the entire system, including the controller and web-based control interface, is on the order of 5% or less than one would expect to pay for a commercial syringe pump having similar performance. The design should suit the needs of a given research activity requiring a syringe pump including carefully controlled dosing of reagents, pharmaceuticals, and delivery of viscous 3-D printer media among other applications.”
Pearce Research group also provides an Open Source Lab page dedicated to low-cost, open-source lab hardware.