RU231996U1 - DEVICE FOR OPERANT CONDITIONING OF SMALL LABORATORY ANIMALS - Google Patents

Abstract

The utility model relates to the field of biomedical and veterinary technologies and is intended to assess the impact of the consequences of the behavior of small laboratory animals on the behavior itself. The technical result consists in expanding the arsenal of means for assessing the cognitive abilities of animals while increasing the speed and accuracy of training. The device comprises a housing 1, inside which there are infrared sensors 5 for detecting the presence of an animal in a target location, placed in compartments 6, an automatic feed supply module including a feeder 2, a rotor 3, a stepper motor 4 and a feed supply compartment 14. In the lower part of the front wall of the housing, three openings are made and a lever for interacting with the animal is located. LED light-emitting diodes are located above the outer openings. The feed supply module is connected to the central opening. The system for controlling the device and transmitting results to the computer is a board with a microcontroller built into the rear wall of the housing. 4 fig.

Description

The utility model relates to the field of biomedical and veterinary technologies and is intended to assess the impact of the consequences of the behavior of small laboratory animals on the behavior itself.

State of the art

The IntelliCage device for studying the cognitive abilities of laboratory animals is known (see Winslow W. et al. IntelliCage automated behavioral phenotyping reveals behavior deficits in the 3xTg-AD mouse model of Alzheimer's disease associated with brain weight //Frontiers in Aging Neuroscience. - 2021. - Vol. 13. - P. 720214). IntelliCage allows for automated cognitive and behavioral screening of mutant and exposed rodents living in social groups. The IntelliCage system minimizes the influence of the experimenter's presence on the behavior of experimental animals to observe normal social behavior of rodents in the natural environment.

The disadvantages of the device include the high price of the device on the Russian market, as well as a closed system that requires a long preliminary setup.

A device for testing animals for conducting a behavioral test of a test animal is known, comprising: a cage defining the habitat of the test animal; a chamber into which the test animal can enter, removably attached to the cage; a test unit located in the chamber, representing a problem for the test animal that has entered the chamber, detecting the reaction of the test animal to the problem and receiving data on the reaction; a position measuring device that measures the position of the test animal in the cage and chamber and receives data on the position of the test animal;
a data storage unit that stores response data and position data as test data; and a problem improvement unit that improves a problem represented by a test unit based on the test data (US20160120153 published 2016-05-05, IPC A01K 1/03). The device can automatically optimize tests performed for animal testing.

Also known is an experimental device for guiding a mouse to search for an escape platform using visual cues (see patent CN113384231, IPC A61B3/02, published on 09.06.2023), which comprises a base with a round water tank, a central platform, an escape platform and a light-emitting diode; the flickering of the light-emitting diode is used as a visual cue, so that the experimental mouse is directed to the escape platform, and the escape is carried out; and the visual function of the experimental device is that it contains a mouse that can be quantitatively analyzed according to the recorded escape time.

The disadvantage of this device is the complex system, which is large in size and cannot be reproduced in a large number of devices for serial measurements.

A device for testing the autonomous social behavior of small animals is known (see patent CN112237156, IPC A01K1/03, published on July 22, 2022), which comprises a test bin, a front branch pipe for storing objects and a rear branch pipe for storing objects located on two outer walls of the test bin, respectively, the front branch pipe for storing objects and the rear branch pipe for storing objects are separated from the inside of the test bin by dividing nets made of iron wire and a guide rail. A groove, a lifting door and a lifting mechanism that drives the lifting door for raising and lowering are located on the side wall of the test bin. The lifting mechanism comprises a motor, two sides of the lifting door are inserted into the insert groove of the guide rail, a microswitch is located on the inner wall of the test bin, the microswitch is electrically connected to the lifting mechanism, the microswitch is electrically connected to the counter, and the microswitch and the measuring device are electrically connected to each other. The motor is electrically connected to the door control circuit; and the door control circuit comprises a time-delay cut-off relay, a forward and reverse motor rotation controller, a time-delay control relay, a sliding rheostat, and an infrared camera.

The disadvantage of this device is the small number of parameters that allow for an analysis of the cognitive abilities of experimental animals.

The closest to the proposed one is a system for automated control of animal training and discrimination skills (see patent US11369093, IPC A61K39/00, published 06/28/2022), based on the analysis of animal behavior and training). A monitoring system for tracking the movement of one or more animals comprises a housing configured to contain one or more animals; a plurality of proximity sensors located inside the housing and configured to detect the presence of one or more animals in a target location and at least one other location; a food delivery system configured to deliver a food reward to the housing; a camera configured to record one or more animals in the housing; at least one auditory stimulus device configured to deliver an auditory stimulus in response to detecting the presence of one or more animals in the target location; at least one light stimulus device configured to deliver a light stimulus in response to detecting the presence of one or more animals in the target location; and a control system configured to receive an input signal from at least one of a plurality of proximity sensors and to control the delivery of a food reward from the food delivery system based on the input signal, wherein the housing comprises an aquarium. The plurality of proximity sensors include a reflector that is configured to detect the presence of one or more animals at a target location when the signal to the reflector is interrupted. The delivery system includes a food-containing portion and a food delivery element that, upon receiving a food delivery signal from the control system, causes the delivery of a food reward from the food-containing portion to the enclosure. The delivery system includes a positioning element that is configured to move the food delivery element from a first position to a second position, wherein the movement from the first position to the second position allows the food reward to be delivered to different areas of the enclosure, and the delivery system is configured to receive a positioning signal from the control system to adjust the location of the food delivery element. The positioning element comprises one or more motors that are configured to adjust the location of the food delivery element by rotating the delivery lever.

The disadvantage of this device is the lack of flexible adjustment of experimental conditions and control of several devices simultaneously. According to the text of the patent, animal movement tracking using a camera is used to improve the quality of measurements.

Disclosure of the essence of the utility model

The technical challenge is to develop an automated device that allows interaction with laboratory animals to study their learning behavior.

The technical result consists in expanding the arsenal of means for assessing the cognitive abilities of animals while increasing the speed and accuracy of learning.

The technical result is achieved in that in a device for operant conditioning of small laboratory animals, comprising a housing, inside which infrared sensors are located for detecting the presence of an animal in a target location, an automatic feed delivery module and a device control system, according to the solution, three openings are made in the lower part of the front wall of the housing and a lever is located for interacting with the animal, LEDs are located above the outer openings, infrared sensors for detecting the presence of an animal are placed in compartments in the lower part of the housing opposite the outer openings, a feed delivery module is connected to the central opening, the device control system and the transmission of results to the computer is a board with a microcontroller built into the rear wall of the housing. The automatic feed delivery module includes a feeder connected to a rotor for dumping food along a guide into a compartment opposite the central opening, controlled by a stepper motor, wherein the stepper motor driver is installed on the rear wall of the housing. The rear wall of the housing is removable and attached to the housing using magnets located in the corners. The housing is made of opaque PLA plastic. The compartments for mounting the infrared sensors are replaceable and are attached to the body using a dovetail system.

Brief description of the drawings

The utility model is explained by drawings, in Fig. 1 - a general view of the device is shown; in Fig. 2 - an automatic feed supply module; in Fig. 3 - the front wall of the housing; in Fig. 4 - the rear wall of the housing.

The following positions are indicated on the drawings:

1. body;

2. feeder;

3. rotor;

4. stepper motor;

5. infrared sensors;

6. compartments for mounting sensors;

7. openings in the front wall of the housing for interaction with the laboratory animal;

8. LED-light-emitting diodes;

9. lever for pressing;

10. rear wall of the case;

11. stepper motor driver;

12. Arduino Nano;

13. magnets;

14. Feeding compartment.

Implementation of a utility model

The device is an operant chamber placed in a laboratory cage (Fig. 1). It contains a housing 1 made of PLA plastic. The choice of this plastic is due to the ease of manufacturing the housing, the optimal properties of the plastic for cleaning the housing, and its opacity prevents the laboratory animal from being distracted by stimuli. Inside the housing of the device there is a module for automatic feeding, consisting of a feeder 2 connected to a vertically located rotor 3 in a housing made of PLA plastic, on which a stepper motor 4 is fixed, used to rotate the rotor 3 and dispense an exact portion of food into compartment 14 along the walls of the rotor housing. Rotor 3 has 8 blades, each of which allows you to take an exact volume of food, and rotates 45 degrees to dump the food into compartment 14, combined with the module. The device contains infrared sensors 5, placed in compartments for fastening sensors 6 in the lower part of the housing 1. Infrared sensors 5 are used to detect the placement of the nose of the laboratory animal in one of the extreme openings of the device. Compartments for fastening infrared sensors 6 are replaceable and are attached to the housing using a dovetail system. In the front wall of the housing 1, three openings 7 are made for interaction with the laboratory animal. The module for automatic feeding is brought to the central opening and is intended to implement food reinforcement of the laboratory animal with food in the event of choosing the correct opening (Fig. 2).

Above the outer holes there are LED diodes 8, which are intended to indicate the correct hole for the laboratory animal to choose. Choosing the correct hole allows you to consolidate the conditioned reflex of the laboratory animal by receiving food reinforcement in the case of the correct choice.

The compartments 6 are located opposite the outermost openings. A lever for pressing 9 is fixed in the lower right part of the device (Fig. 3). It allows to obtain more accurate results of the experiment by providing several tasks for the laboratory animal. A stepper motor driver 11 (Fig. 4) is installed on the back wall 10 of the housing 1; a board with an Arduino Nano microcontroller 12 is also built into the wall, which controls the device and transmits the results to the computer. The stepper motor driver 11 allows to precisely control the stepper motor 4, it is connected to the board with the microcontroller 12. The board with the microcontroller 12 controls the device: sets the conditions for the burning of the LED light-emitting diodes 8 according to the experiment, receives a signal from the infrared sensors 5, controls the stepper motor 4 via the stepper motor driver 11 and transmits all the received data to the personal computer to which it is connected. The back wall of the device 10 is a flat plate made of opaque PLA plastic. Magnets 13 with a diameter of 3 mm in the upper part and 5 mm in the lower part are fixed along its edges, used for fixing the rear wall 10 to the body of the device 1, which allows for quick removal of the rear wall 10 and access to the main technical units of the device. The device allows for operant conditioning in accordance with signals. LEDs 8 are used as signals. The task for the animal is to choose the correct hole 7 or press the lever 9. Thus, if a small laboratory animal places its head in the correct hole 7, which is one of the outer ones, the infrared sensor 5 registers this and sends a signal to the board with the microcontroller 12. The board with the microcontroller 12 controls the device, turns on the module for active feed delivery, and the animal receives a dosed portion of feed as a food reinforcement in the central hole. After that, the information is sent to a personal computer, to which the board with the microcontroller 12 is connected via a USB interface. If the laboratory animal chooses the wrong hole, the dosed portion of food is not dispensed, information about this is sent to the personal computer via the board with the microcontroller 12. The time and conditions of the experiment are set on the computer. At the end, the results are provided as a txt file.

Training procedure. 24 hours before the training, the laboratory animal is subjected to food or water deprivation. Then the animal is placed in a prepared laboratory cage with a device placed in it. For 30 minutes, the animal is in the same cage with the device, which automatically provides food reinforcement as a reward for choosing any of the two outer holes. This procedure is carried out until the animals are confidently trained to receive reinforcement in the feeder. On average, 7 to 10 training sessions are required. After the experience is consolidated, the animal is again placed in the laboratory cage with the device. Settings are set so that the LED 8 lights up only above one of the two outer holes, where the infrared sensors 5 are installed. The time for recording the correct choice, lighting up the LEDs 8 and selecting an individual LED 8 for lighting is configured by controlling the device through the board with the microcontroller 12. Such variability allows you to set different experimental conditions to obtain more accurate results. After passing the tests with LEDs 8, the signal from the pressing lever 9 is registered. All LEDs 8 light up, signaling the correctness of the choice. In case of pressing the lever 9, the laboratory animal receives food as a reinforcer.

The device is designed for testing laboratory animals while ensuring high comfort for animals and reducing the workload on operators to a minimum. Simultaneous operation with an unlimited number of devices in the system allows scaling experiments and studies with large groups of animals. The device allows for analysis of reaction time, learning time, total time to reach the goal and the number of errors.

Claims (5)

1. A device for operant conditioning of small laboratory animals, comprising a housing, inside which are located infrared sensors for detecting the presence of an animal in a target location, an automatic feed delivery module and a device control system, characterized in that in the lower part of the front wall of the housing there are three openings and a lever for interacting with the animal is located, LEDs are located above the outer openings, infrared sensors for detecting the presence of an animal are located in compartments in the lower part of the housing opposite the outer openings, the feed delivery module is connected to the central opening, the device control system and the transmission of results to a computer is a board with a microcontroller built into the rear wall of the housing. 2. The device according to item 1, characterized in that the automatic feed supply module includes a feeder connected to a rotor for discharging feed along a guide into a compartment opposite the central opening, controlled by a stepper motor, wherein the stepper motor driver is installed on the rear wall of the housing. 3. The device according to item 1, characterized in that the rear wall of the housing is removable and attached to the housing using magnets located in the corners. 4. The device according to item 1, characterized in that the body is made of opaque PLA plastic. 5. The device according to item 1, characterized in that the compartments for attaching the infrared sensors are replaceable and are attached to the body using a dovetail joint.