EP1898695A2

EP1898695A2 - Metabolic cage for small rodents

Info

Publication number: EP1898695A2
Application number: EP06778996A
Authority: EP
Inventors: Patrick Even
Original assignee: Institut National de la Recherche Agronomique INRA
Current assignee: Institut National de la Recherche Agronomique INRA
Priority date: 2005-06-30
Filing date: 2006-06-29
Publication date: 2008-03-19
Also published as: WO2007003854A2; CA2613220A1; FR2887745B1; FR2887745A1; WO2007003854A3; US20080196672A1

Abstract

The invention concerns a metabolic cage (1) for small rodents, comprising: a living chamber (20) designed to receive a rodent; a technical mount (30), said living chamber (20) and said technical mount (30) comprising each complementary nesting elements, enabling the living chamber (20) to be assembled and released relative to the technical mount (30).

Description

Metabolic cage for small rodents

The present invention generally relates to a metabolic cage for small rodents. Elfe more particularly relates to a modular metabolic cage, consisting of a housing chamber that can be equipped with different modules according to the needs of users.

Metabolic cages make it possible to study parameters that contribute to the regulation of energy balance, such as food intake in mice, rats, and hamsters.

The mouse is an excellent model for defining the functions of mammalian genes, because it has great genetic, immunological, reproductive, physiological and pathological similarities with humans.

Consequently, genomic and proteomic studies showing the involvement of genes and proteins in different human pathologies have opened new therapeutic avenues in biomedicine. The function of genes must be established not only at the molecular level, but also in animals. The testing of pharmaceutical compounds in the preclinical (pharmacology, toxicology) study phase in vivo requires the physiological and behavioral phenotyping of the animal model used. . Phenotyping consists of (i) defining the set of functional characters, conditioned by an individual's genetic heritage and its interaction with the environment, and (ii) detecting variations from a norm. To carry out these studies, metabolic cages are nowadays widely used.

More generally, metabolic cages are also widely used for biomedical research and the development of therapeutic compounds, as has been has been described above, but also to carry out phenotypic studies in developmental biology, neuroscience, oncology or for the preclinical development of drugs. In all these areas, the important potential of metabolic cages is also their non-invasive nature, which allows animals to be tracked over time through repetitive observation of animals.

Metabolic cages are generally designed to perform one or two types of measurements. There are thus metabolic cages to measure the content of urine and faeces of animals or metabolic cages to measure energy expenditure through measurements of respiratory exchanges. Therefore, when a wide variety of phenotypic measurements are to be made on an animal, two solutions are generally available. A first solution consists in using several metabolic cages, each being devolved to a particular type of measurement. This solution is, however, unsatisfactory because it involves a multiplication of the number of metabolic cages required when carrying out studies on a group of animals. A second solution is to use more complex metabolic cages, equipped with a larger set of measuring elements, so expensive.

Therefore, there is a need for new metabolic cages, which can easily adapt to the needs of users, and in particular that can be equipped with different measuring elements depending on the complexity and variety of measurements to be made on the animal.

Another disadvantage of conventional metabolic cages, lies in the stress inflicted on animals before the experiment which causes wastes of time during the experiments. For better reproducibility of the tests, especially in order to minimize animal stress, and in order to reduce the immobilization time of the test devices coupled to the metabolic cages, between two experiments, it would be desirable to have improved metabolic cages, relative to to those known.

The need for new metabolic cages, adaptable to users' constraints, is all the more important since the rodent phenotyping studies, in constant development, considerably facilitate the characterization of the pathogenic factors involved in many human pathological syndromes.

The inventors have developed a metabolic cage meeting the needs described above. The invention relates to a metabolic cage for small rodents comprising:

- a living room intended to accommodate a rodent, said living room comprising side walls and a floor provided with cells for evacuation of urine and faeces by gravity, and

- A technical base comprising a funnel for receiving and separating said urine and faeces to a container. Said technical base also comprises at least a support part intended to receive a module useful for the implementation of the metabolic cage, in particular for the phenotyping of small rodents.

Preferably, the technical base comprises 1, 2, 3, 4, 5 or 6 support portions, preferably 1 to 4 support portions, each intended to receive a module. According to the invention, said living chamber and said technical base each comprise complementary interlocking elements, allowing the assembly and the release of the living room relative to the technical base.

In other words, said metabolic cage thus comprises a first functional position in which the technical base is in contact with the floor of the living room and a second functional position in which the technical base is separated from the chamber of dwelling.

By "functional position" is meant according to the present invention, a configuration in which the rodent is present in the living room.

The living room can be separated from the technical base when a rodent is present in the living room. This dwelling room can be the permanent housing or transient of the animal, which can be mounted on a single base, and be for example stored individually or rack. This complete dissociation between the living room and the technical base has many advantages. Thus, a rodent can be placed in the living room for a period longer or shorter, defined by the user, before the living room is brought into contact with the technical base, and that measures start. In this way, the animals benefit from a period of acclimation time favorable to the reduction of the stress, before the tests for the realization of which the living room is placed on a technical base.

Users can thus have a greater number of living rooms than the number of technical bases and / or implementation modules, so that the use of the technical base and the implementation modules is optimized. . By "rodent" or "small rodent" is meant according to the present invention a small animal, and preferably a mouse, a rat or a hamster.

Preferably, the metabolic cage described above further comprises an actimetry platform placed in contact with the technical base, comprising at least one sensor (41), preferably of 1, 2, 3 or 4 sensors, selected from motion sensors, force sensors and weighing sensors, to measure rodent activity.

Between two tests with a metabolic cage according to the invention, the living chamber (20), which contains at least one animal, is nested on a single base, said single base can be equipped with a sensor (41). An actimetry platform makes it possible to measure the activity, in particular the movements of the rodent placed in the living room.

By way of example, the force sensor may be a piezoelectric type force sensor. In particular, it is possible to use weighing micro-sensors of the type commonly used in the manufacture of precision balances.

The actimetry platform described above may for example comprise 3 or 4 sensors, so that the movements of the rodent can be analyzed in detail. In particular, the use of 3 or 4 sensors makes it possible to measure the position of the rodent within the dwelling.

The use of 3 or 4 sensors also avoids the use of infrared beams, known to those skilled in the art, to define the position of the rodent in the cage.

Thus, the actimetry platform advantageously comprises 1, 2, 3 or 4 piezoelectric sensors.

When only physical activity or level of alertness should be measured, but not the position of the rodent, the use of a single sensor is sufficient. In a particular embodiment of the invention, the metabolic cage comprises a device for controlling the position of the small rodent in the dwelling chamber by infrared beam. Optionally, the metabolic cage may further comprise at least one implementation module of which one of the side walls allows communication with the volume formed by the living room, so that a rodent placed in said chamber dwelling can access the module.

The metabolic cage and the implementation modules, described above, have a size adapted to the type of animal studied. For example a small metabolic cage is used to study a mouse, a medium-sized metabolic cage is used to study a hamster and a large metabolic cage is used to study a rat.

By "accessing" an implementation module, especially a feeder module or a water supply module, the skilled person will understand that a rodent, placed in the living room can pass his head, the anterior part of his body in said module. A "refuge" module, specially designed for the passage of the complete body of the animal can be fixed to the living room (20), in some embodiments.

Preferably, said module is separated from the living room by a shut-off opening. By way of example, the shut-off opening may consist of a diaphragm or a sliding panel. Thus, access to the module can be controlled by the user.

Said module may comprise a solid or liquid food reserve, and in particular a feeder or a feeding bottle. Said module can also be constituted by a container delimiting a void space in which the rodent can be isolated, for example to sleep, access to said module being adapted to the size of the animal.

Preferably, the implementation modules comprising a solid or liquid food reserve, further comprise a weighing sensor, so that it is possible to measure the food intake or the intake of liquid of the animal. In other embodiments, in particular for carrying out tests for which the measurement of the consumption of water and food is not required, it is possible to use implementation modules equipped with a manger and / or a bottle, which do not include a sensor, in particular a weighing sensor

The metabolic cage may comprise 1 to 6 implementation modules, advantageously from 1 to 4 modulas, and preferably 1 or 2 implementation modules, said modules being identical or different from each other.

The arrangement of several types of modules thus allows the user to adapt the metabolic cage to the type of measurement that he wants to perform. The fact of having several types of modules makes it possible, for example, to test food choices of an animal or to carry out aversion or learning tests well known to those skilled in the art, and which will therefore not be described here. in detail . The use of 3 modules, each including a feeder for example to measure respectively the amount of proteins, lipids and carbohydrates consumed by the animal and to determine the sequence in which these nutrients are ingested. The living room includes a removable ceiling, which is optionally sealed. When the living room is sealed, it may further comprise a calorimetry measuring device, and in particular, a device for measuring the respiratory exchanges. For example, the device for measuring respiratory exchanges comprises successively:

- Fresh air intake means,

one or more fans placed in the metabolic cage, where appropriate in the removable ceiling (24), and / or in the implementation modules.

a means of evacuation of stale air,

a means for measuring the level of O 2 and / or CO 2 in the stale air, and a means for measuring the flow of air through the metabolic cage.

Thus, when the metabolic cage comprises both a module comprising solid or liquid food, and a device for measuring respiratory exchanges, the user can control a set of parameters that participate in the regulation of the energy balance of the animal. , and especially food intake and energy expenditure. In addition, when using an actimetry platform (40), the influence of rodent activity in the energy balance can be taken into account.

The urine volume of small rodents being quite low, the funnel for recovering urine can be equipped with a humidification device comprising a rinsing means of said funnel, to optimize the recovery of urine.

For example, a closed circuit of water circulation can be established between the funnel, and the container for collecting urine and feces. For this purpose, distilled water is placed in the container for collecting urine and feces. A pump, for example a peristaltic pump can thus be added to the technical base, near the funnel, so as to pump the water contained in the container for collecting the urine and feces, the water being then rejected in the upper part of the funnel, to moisten it. According to an alternative embodiment, said container is replaced by a connector connected to one end of a tube, the other end of said tube being connected to a pump, said pump being in fluid communication with a collection container of fractions allowing a sampling urine at certain times.

The metabolic cage described above may furthermore comprise one or more hydraulic and / or electrical cables penetrating into the living chamber, the said cable or cables being intended to take measurements on the rodent or to carry out infusions or samplings. .

The use of a cable makes it possible, for example, to take blood samples from the rodent placed in the living room or to inject a liquid into it. The cable may also provide electrical stimulation of the rodent or recordings of physiological electrical signals such as blood pressure, heart rate or neural activities, if the animal is previously equipped for these measurements. The remainder of the description refers to the appended figures.

Figures 1 to 8 show a general embodiment of a metabolic cage according to the invention. Figures 9 to 14 show particular embodiments of the metabolic cage of the invention. Figures 1 to 14 show, respectively:

1 is a general view of a metabolic cage 1, according to the invention, comprising a living chamber 20, a technical base 30, and a rackable support platform 40 which, if it is equipped with force or weighing becomes an actimetry platform 40.

FIG. 2: an exploded view of the interior of the technical base 30,

Figure 3: a sectional view, along a horizontal plane, of a metabolic cage equipped with 4 modules 50 and posed on an actimetry platform 40 comprising three movement or weighing sensors 41 arranged in a triangle,

Figure 4A: a perspective view of a general actimetry frame 43 for receiving a metabolic cage according to the invention or any cage.

4B: the frame 43 of FIG. 4A, shown in section, in a vertical plane;

FIG. 5: a general view of a metabolic cage 1, comprising two modules 50, FIG. 6: a sectional view, in a vertical plane, of the metabolic cage 1 represented in FIG. 5,

FIG. 7: a view of a detail of FIG. 5, representing the lower part of a module 50,

8: a general view of a metabolic cage 1, according to the invention, comprising a living chamber 20, a technical base 30, an actimetry platform 40, and a cable 60 supported by a bracket 61 and balanced by pulley system 63 and counterweight 64.

9: a general view of a metabolic cage 1, according to the invention, comprising a living room 20, closed by a removable roof (24) here equipped with a fan

(241) and a stale exhaust means (242), a rackable technical base (30), equipped with two modules

50, and an actimetry platform (40), equipped with 4 feet. The actimetry platform is equipped with several force or weigh sensors (41). In this configuration it is possible to perform multi-parametric studies, that is to say, measure the respiratory exchanges, food intake, intake and movements of the animal. By transferring the feet directly under the technical base (30) it is also possible to work without the platform of actimetry.

10: a view of the technical base (30) with its funnel (31) and sieve (33) for the recovery and separation of urine and feces, on which are visible the reception areas of the modules 50 (34), and equipped with a module implementation (50) and placed on a support 40. On this base there is also a technical plate for the electrical and hydraulic connections (36).

Figure 1 1: view from above in a horizontal plane of a metabolic cage (20) equipped with its floor (22) provided with cells (23) and placed on a technical base (30) equipped with 2 modules 50. On this the location of the modules 50 and the brackets (34) and the sliding doors (35) closing the openings of the living room are shown.

12: sectional view in a vertical plane of a metabolic cage 1, closed by a cover (24), equipped with its technical base (30), all resting on an actimetry platform 40 equipped with sensors force (41). In this figure the honeycomb floor (22-23), the funnel (31) and the feces retention screen (33) are also shown. The urine can be collected in a container (32) or a connector (321) attached to a tube to a refrigerated container or fraction collector. Figure 13: same view shown in Figure 5 of the metabolic cage 1, equipped with a module (50), a bracket (61) provided with a cable (60) équ ilibré by a pulley system (63) ) and counterweight (64). In this figure the cage is configured to allow the recording of respiratory exchanges. The cable entry is sealed by a flexible sleeve (65) closed on the cable and the cable gland (43). The lid (24) is equipped with a fan (241) and a stale air extraction outlet (242).

Figure 14 is a side sectional view of a module 50 equipped for measuring the food intake (7a) and a module equipped for measuring the intake (7b). Preferably the module is equipped with a measurement sensor (502), a manger support (503) and a feeder (505) or a bottle support (504) and a bottle (506), a protective casing (501) and a hood preferably transparent (507) to cover the protective case and allow access from the living room. In an "all-purpose" configuration, any type of technical element may be integrated in the module (50). An empty module (50) of suitable size can also be used as a niche to improve the comfort of the animal and allow a behavior closer to the wild.

In the following description and on the drawings and in order to bring them more concision and clarity, the same reference numerals are used to designate identical organs or objects allowing the implementation of the method which is the subject of the invention.

The metabolic cage (1) for small rodents, object of the invention, shown schematically in Figure 1, comprises a living room (20) for accommodating a rodent, said living room (20) comprising side walls (21) and a floor (22) provided with cells (23) for evacuation of urine and faeces by gravity, and - a technical base 30 comprising a funnel (31) for receiving and directing said urine and faeces to a container (32), said living chamber 20 and said technical base (30) each comprising complementary interlocking elements, allowing assembly and release of the living chamber (20) relative to the technical base (30).

In other words, said metabolic cage (1) comprises a first functional position in which the technical base (30) is in contact with the living chamber (20) (FIGS. 1 and 9) and a second functional position in which the technical base (30) is separated from the living chamber (20) (Figures 2 and 10).

Alternatively, the container (32) can be replaced by a connector (321) and a tube connected to a pump and to a fraction collector allowing a sequential collection of urine and / or its recovery in a refrigerated container (Figure 12).

Said technical base (30) also comprises at least one support portion for receiving a module (50) useful for the implementation of the metabolic cage (1), in particular for phenotyping small rodents (Figure 1). In the embodiment of Figure 10, the technical base (30) comprises a reception area or support (34) for receiving a module (50) for implementing the metabolic cage (1). In this embodiment, the reception or support area (34) of the base (30) may comprise a technical plate (36) of the type supporting the electric and / or hydraulic cables may be connected to the 'animal.

Preferably, the technical base 30 comprises 1, 2, 3 or 4, support portions (34, FIG. 1) or 1, 2, 3 or 4 support zone type support portions (34, FIG. 10). Any of these supports (34) may be used to secure an implementation module (50) (FIGS. 5, 10) and / or a bracket (61, FIGS. 8, 13).

By way of example, as shown in FIGS. 1 and 11, the technical base (30) comprises two support portions (34, FIG. 1), or two reception or support zones (34, FIG. 1). 1) each intended to receive a module (50).

The technical base (30) can be equipped with a power supply device, for example a technical plate (35, FIG. 8) or a technical plate of the stem type (35, FIG. 10) making it possible to bring electric current. inside the technical base (30), for centralized electrical connections, for example to power one or more small devices such as a fan (241, Figures 9, 13). The side walls (21) of the living room constitute a cylinder, so that the volume available to the animal is maximum.

Preferably, the living room (20) comprises a ceiling (24). In some cases, this ceiling can be sealed to the living room (20). The living room (20), or the ceiling (24), can be equipped with a fan (241). Said fan (241) can be associated with a thermoregulation system, in order to ensure precise control of the temperature of the living room (20).

As it appears more clearly on the part of the technical base (30) represented in FIGS. 2, 10 and 12, a second screen or sieve (33) can be placed in the technical base (30), within the funnel (31), so as to separate the urine and feces of the small rodent. Preferably, this second screen or sieve (33) is made of stainless steel.

Preferably, the side walls 21 of the living room are made of a transparent material, washable and can be sterilized by the aid of chemical agents.

The floor (22) may be a stainless steel plate pierced with cells (23), or consist of any mesh suitable for the comfort and safety of the animal, for example stainless steel.

Preferably, the funnel (31) for receiving urine and faeces, is also made of stainless steel or a hydrophobic material such as Teflon®. The funnel (21) advantageously has a very smooth surface for the proper flow of urine.

Alternatively, the elements likely to be in contact with the animal or body fluids of the animal may be made of ceramic, so as to avoid corrosion. Thus, the funnel (31), the container (32), intended for collecting the urine and feces or the floor (22) of the living room (20) may be made of ceramic, glass or plastics compatible with biological fluids. The technical base (30) can be made of any material, washable in a dishwasher, and autoclavable for metal elements.

In a preferred embodiment of the invention, the metabolic cage (1) may further comprise an actimetry platform (40) placed in contact with the technical base (30), said platform actimetry device (40) comprising at least one motion sensor (41), preferably a force sensor applied to the platform. The actimetry platform (40) shown in FIGS. 1 and 3 has 3 piezoelectric force sensors (41).

By way of example, the technical base (30) and / or the actimetry platform (40) can be square in shape, so that several metabolic cages (1) can be placed in a rack.

In a particular embodiment of the invention, the technical base (30) rests on the frame (43) shown in FIG. 4. This frame (43) rests on four supports (42) interconnected by four arms. (44) forming an "X" at the center of which is placed a single motion sensor (41).

The supports (42) may be composed of a piston (421) running in a cham ber (422), so as to ensure the stability of the frame (43). This simplified embodiment, in which the number of motion sensors is reduced to a single sensor (41), makes it possible to reduce the cost of the actimetry platform (30), while making it possible to carry out a set of measurements. complexes on the studied rodent such as the measure of its physical activity or the control of the sleep. This platform Actimetry (30) can also be used alone with standard pet housing cages.

By way of example, it is possible to use sensors capable of withstanding a mass of 50 kg, making it possible to detect force variations of 0.1 g or even sensors capable of withstanding a mass of 25 kg, making it possible to detect force variations of 0.05 g.

More particularly for measurements of the motor activity of the animal, other types of sensors, for example less expensive, may be used, such as weighing bars.

The metabolic cage (1) may further comprise at least one module (50) forming an internal volume communicating with the volume formed by the living room (20), so that a rodent placed in the living room ( 20) can access said module (50).

A metabolic cage (1), comprising two modules (50) is shown in Figures 5, 9 and 1 1.

Figures 3 and 1 1 show a top view of two standard embodiments of the metabolic cage

(1), wherein the metabolic cage (1) comprises four modules (50, Figure 3) or two modules (50, Figure 1 1). The module (50) may include a solid or liquid food supply. This food supply may be a feeder (51, Figs. 5, 6, 11, 14A) or a feeding bottle (52, Figs. 5, 6, 11, 14B).

Figures 6, 12, 13 each show a sectional view of a metabolic cage (1), comprising two modules

(50), the first is equipped with a feeder (51), and the second module (50) comprises a feeding bottle (52).

The module (50) forms an open volume on the living room (20), thanks to an opening (53) made in the wall (21) of the living room (20).

When the module (50) comprises a feeder (51) or a feeding bottle (52), the opening (53) will preferably have a surface large enough for the rodent to pass the head through the opening, and thus reach the feeder (51) or bottle (52), but narrow enough to prevent the dispersion of food by the animal and prevent the animal is placed on the feeder or the bottle of the module (50).

Alternatively or simultaneously, the metabolic cage (1) may comprise an empty module (50), that is to say without a feeder or a feeding bottle, said module (50) communicating with the living room (20) with a opening large enough that the rodent can enter the module (50), so for example that the latter can rest. The module (50) then constitutes a niche for the rodent. The module (50) may also include other elements such as a switch or more generally a control device, which the rodent can actuate itself.

By way of example, as shown in FIG. 6, the module (50) may comprise a floor (56) intended to accommodate a bottle (52) or a manger (51) placed at the same level as the floor ( 22) of the living room (20), two vertical side walls (54), (FIG. 5) and a rear wall (55), in contact with the living room (20), so as to form a space closed with the living room (20).

Also as an example, as shown in FIG. 14, the module 50 may comprise a housing intended to accommodate the measuring sensor (502), the feeder support (503) or the feeding bottle (504) and having elements (508) necessary for its fixing on the reception areas of the technical base. The housing is covered with a cover (55), preferably transparent so as to form a closed space after the contact of the module 50 with the living room. Finally, an opening (53) is arranged between the module (50) and the living room (20).

Optionally, the opening (53) can be closed by a diaphragm or a sliding wall which can be motorized to program automatic openings and / or closures.

A closing system of the openings (53) can also be provided, so that the openings (53) are locked when the metabolic cage (1) is in the second functional position in which the technical base (30) is separated of the living room (20).

In the case of a sealed assembly, for example to measure the respiratory exchanges, the sealing of the space formed by the association of the living room (20) with the module (50) is ensured by placed joints on the edges of the side walls (54) and rear (55) of the module

(50), in contact with the living room (20) (Figure 5).

In other embodiments, seals are placed between the walls (55) and interface plates (35) of the living room (20) (FIGS. 11 and 12).

Preferably, the metabolic cage (1) comprises 1 to 4 modules (50).

In the embodiment shown in Figure 1 1, the metabolic cage (1) comprises two modules (50), but have two supports (34) additional to fix four modules (50) in total.

Figures 5 and 12 show the details of modules (50) including a feeder (51) or a bottle (52). Figure 7 shows in detail a module (50) including a feeder (51). The floor (56) of the module (50) is composed of a rear part (561), intended to accommodate the weighing sensor (57), or an inert support, and a front part (562), comprising the feeder ( 51), intended to accommodate the rodent's head. Optionally, the module (50) may include a sensor (57) for measuring the mass of food contained in the feeder (51). As can be seen in FIG. 7, the sensor (57) comprises connection means (58), which communicate with the outside of the module (50).

Figure 14 shows, in another embodiment, the detail of a module (50) comprising a feeder (14A) or a bottle (14B). The feeder and the bottle are protected by a floor (56) in which is formed a hole allowing access to food or water. The housing (501) of the module (50) is equipped with a device (508) for attachment to the receiving areas (34) of the technical base (30). Optionally it contains a sensor (502) on which is fixed the feeder (503) or the bottle (504).

In a particular embodiment of the invention, the living room (20) can be sealed to fluids, liquids, gases, or both, including through the use of a ceiling (24). When the living room (20) is sealed, it can be equipped with a device for measuring exchanges, in particular gaseous fluids, especially respiratory exchanges.

This device for measuring respiratory exchanges, an embodiment of which is represented in particular in FIG. 13, comprises:

- A fresh air intake means, preferably located on the lower part of the living room (20),

- one or more fans (241) placed in the metabolic cage (1) and / or in the modules (50)

- Exhaust air removal means (242),

a means for measuring the level of O 2 and / or CO 2 in the stale air, and

a means for measuring the flow of air through the metabolic cage (1). The means for supplying fresh air and stale exhaust air are for example each constituted of a tube connected to a pump.

For example, the means for measuring the CO2 content in the exhaust air is composed of cells for analysis of IO2 and CO2, placed in bypass on the fresh air intake and exhaust air intake tubes. 'stale air.

Such a measuring device makes it possible to know the energy balance of the rodent placed in the living room. The metabolic cage (1) described above may also be equipped with the optional equipment described hereinafter, which allows the user to adapt the metaboliage cage (1) to his needs.

For example, the funnel (31) included in the technical base (30) may be equipped with a humidification device comprising a rinsing means. A humidification device makes it possible to avoid the evaporation of the small quantities of urine produced by the rodents placed in the living room. Optionally, when the metabolic cage (1) is devoid of actimetry platform (40), a device for controlling the position of the small rodent in the living room (20) by infrared beam can be added to the chamber dwelling (20). Such a system is quite conventional for those skilled in the art and will not be described in detail.

In a particular embodiment of the invention, shown in FIGS. 8 and 13, the metabolic cage (1) comprises one or more hydraulic and / or electrical cables (60) situated above the living room ( 20), the one or more cables (60) being intended to carry out different measurements or to carry out infusions or samples from the small rodent.

The cable (60) is connected to a bracket (61) fixed to the technical base (30) by the support parts (34), and the back and forth movements induced by the activity of the animal are compensated by a pulley (63) provided with a counterweight (64) adapted to the weight of the cable or cables (60).

In addition, the ceiling (24) may comprise a bore allowing passage of the cable or cables (60) inside the living chamber (20) (Figures 8 and 13). On the face

13, there is also shown the fixing of a suitable cable gland (243).

In the case where the metabolic cage (1) must remain sealed, a sealing sleeve (65) can be fixed between the cable or cables (60) and the cover (24) (FIG. 8) or between the cable or cables ( 60) and the grommet (243) (FIG. 13).

The cable or cables (60) can be connected, via the means (62), to devices for sampling blood, for example a syringe, or to devices for micro-dialysis or the administration of exogenous substances, for example, physiologically active compounds to be tested.

Alternatively, the cable or cables (60) can be connected to a power source so as to be able to perform electrical stimulation of the rodent or intra or extra-cellular recorders.

The cable or cables (60) may further comprise a hydraulic and / or electric rotary joint (66) (FIGS. 8 and 13).

The invention also relates to a method of phenotyping a rodent, comprising the following steps: a) placing a rodent in a living chamber 20 of a metabolic cage (1), said living chamber (20) comprising side walls (21) and a floor (22) provided with cavities (23) for discharging urine and feces by gravity, b) placing the living room (20) in a functional position in which the floor (22) of the living room (20) is separated from a base technical device (30) comprising a funnel (31) for receiving and separating said urine and faeces, by means of a sieve (33) and directing the urine to a container (32), and c) placing the chamber housing (20) in a functional position in which the floor (22) of the living room (20) is in contact with said technical base (30), so that the rodent can be phenotyped.

Claims

1. Metabolic cage (1) for small rodents comprising:

- a living room (20) for housing a rodent, said living room (20) comprising side walls (21) and a floor (22) provided with cells (23) for the evacuation of urine and faeces by gravity, and

- A technical base (30) comprising a funnel (31) for receiving and separating said urine and faeces to a container (32), characterized in that said living chamber (20) and said technical base (30) comprise each of the complementary interlocking elements, allowing assembly and release of the living chamber (20) relative to the technical base (30).

2. Metabolic cage (1) according to claim 1, characterized in that it further comprises, an actimetry platform (40) placed in contact with the technical base (30), said actimetry platform ( 40) comprising at least one sensor selected from a motion sensor (41), a force sensor and a weigh sensor.

3. Metabolic cage (1) according to claim 1 or 2, characterized in that it further comprises at least one module (50), one of the side walls (21) allows communication with the volume formed by the chamber housing (20), so that a rodent placed in said living room (20) can access said module (50)

4. Metabolic cage (1) according to claim 3, characterized in that said module (50) and said living chamber (20) are separated from a closable opening (53).

5. Metabolic cage (1) according to claim 3 or 4, characterized in that it comprises 1 to 6 modules (50), preferably 1 to 4 modules (50), and preferably 1 or 2 modules (50).

6. Metabolic cage (1) according to any one of claims 1 to 5 characterized in that the living room (20) comprises a ceiling (24).

7. metabolic cage (1) according to claim 6 characterized in that it further comprises a device for measuring respiratory exchanges.

8. Metabolic cage (1) according to claim 7, characterized in that said device for measuring the respiratory exchanges comprises successively:

- Fresh air intake means,

one or more fans placed in the metabolic cage (1), and / or in the ceiling (24) and / or in the modules (50),

a means of evacuation of stale air,

a means for measuring the level of O 2 and / or CO 2 in the stale air, and

a means for measuring the flow of air through the metabolic cage (1).

9. Metabolic cage (1) according to any one of claims 1 to 8, characterized in that the funnel (31) is equipped with a humidification device comprising a rinsing means of said funnel.

10. Metabolic cage (1) according to any one of claims 1 to 15, characterized in that it further comprises one or more hydraulic and / or electrical cables (60), which can penetrate the living room (20), the one or more cables (60) being intended to take measurements on the small rodent or to perform infusions or samples.