Patent Application
20150128872
The present invention relates to rodent cages; more particularly, to rodent cages used in scientific research; and most particularly, to rodent cages used during neuroscience-related research where a rodent within the cage is tethered to equipment outside of the cage.
In vivo testing of non-human animals, such as rodents, is essential in many avenues of scientific research. These studies are of particular importance within the neuroscience community as these studies provide valuable insights into the causes and physical manifestations of neurologic disorders as well as indications as to the effectiveness of pharmaceutical treatments of such disorders. Rats and mice are the typical subject animals in neuroscience research. During the course of a study, individual rats or mice are housed within a specialized cage where the animal can be monitored, administered medications or subjected to other research objectives, depending on the goals of the study. Ideally, the rat or mouse should experience minimal influence from laboratory personnel to ensure that the animal's activity is indicative of a “normal” state and is not a result of outside stresses experienced by the animal. Depending upon the research project's design and goals, the rat or mouse may be tethered to equipment located outside of the rodent cage. For instance, the rat or mouse may be hooked up to a drug infusion system, contacted with leads for electrical stimulation or electroencephalography or have a cannula surgically implanted within the skull to enable micro-dialysis infusion/collections of brain or spinal fluids.
There are a number of scientific related rodent cages available. However, each of these cages suffers from one or more significant drawbacks. For instance, one example of a typical rodent cage simply employs a generally cuboidal cage of metal lattice. The floor of the cage is of a lattice construction, such as a wire mesh, allowing for the rodent's urine and feces to pass through the floor to a waste collection bin below the mesh floor. As the rodent lives directly on the metal lattice of the cage bottom, the absence of bedding makes for a highly artificial environment. The metal sides and top also obscure visual observations and limit video monitoring of the rodent. Additionally, the rodent must be handled by laboratory personnel when needing to clean the rodent cage—typically on a daily basis. During the cleaning process, a researcher risks being bitten by the rodent when the rodent is moved from the cage or back into the cage. If left tethered to the external equipment, the experiment can be lost if the tether becomes dislodged from the rodent while the rodent is being moved. If purposely untethered during the cleaning process to avoid loss of the experiment, any data recording or drug infusion must be stopped while the animal is untethered, resulting in the interruption of the experiment.
Alternative cages, particularly those specifically designed for tethered experiments, particularly those where the goal is to eliminate the need to remove any tethers during cleaning, employ a cage construction which has open tops. Thus, a rodent can simply be lifted out of the cage when cleaning. However, the rodent must still be handled by research personnel leading to the same issues described above. Additionally, cages with open tops present difficulties because neuroscience research animals often have pathologies that require complete enclosures. For example, those with epilepsy may have violent seizures during which those animals can jump out of the cage and become suspended by the tethered system. In these instances, the researcher must again handle the animal to return it to its cage. Further, as these are paroxysmal events, if this occurs when no one is present, there is a risk of damage to the scientific equipment as well as to the animal (such as injury, dehydration or death).
What is needed in the art is a rodent cage which addresses the above recited limitations in the art. What is needed is a rodent cage which more closely mimics the living environment of a rodent while also allowing cleaning of the rodent cage with no direct contact with the animal and minimal disturbance to the enclosure. Further needed is a rodent cage having a complete enclosure which is also amenable to unobstructed visual and/or video monitoring of the rodent within the cage.
Briefly described, a rodent cage for housing a rodent in accordance with the present invention generally comprises a cage body having an open bottom end and an open top end defined by integral sidewalls. A channel is situated within an interior surface of at least two opposing walls proximate the top end. The top end of at least one sidewall terminates below the channel thereby enabling slidable engagement of a top panel within the channel. The top panel has at least one opening therein for passage of laboratory equipment. A tray having a bottom and upwardly extending integral tray sidewalls is proportioned so that the cage body rests within the tray during use.
A further embodiment of a rodent cage according to the present invention includes provision of a cage body further including a floor proximate the bottom end of the body. Preferably, the floor is comprised of a plurality of parallel bars and lateral spaces between the bars proportioned such that bedding housed within the cage body passes through the spaces while the rodent remains within the cage body when the cage body is removed from the tray.
Yet another embodiment of a rodent cage according to the present invention includes a the top panel having a plurality of openings therethrough wherein at least one of the openings coincides with an edge of the top panel so as to allow slidable removal of the top panel from the cage body without requiring removal of the laboratory equipment.
In each of the above embodiments, the cage body, top panel and tray may be constructed of any suitable material, but in a preferred embodiment are constructed of a clear plastic; and more preferably constructed of a non-permeable clear acrylic plastic.
The above-mentioned and other features are advantages of this invention, and the manner of attaining them, will become apparent and be better understood by reference to the following description of the invention in conjunction with the accompanying drawings, wherein:
Referring to the drawings in detail, and specifically to
Cage body 110 is generally comprised of integral sidewalls which define an open top end and open bottom end. While the cage body may be formed in any desired shape (i.e. round, square, rectangular, polygonal, etc.), in a preferred embodiment the rodent cage is generally a square or rectangular shape, which allows for the cages to be efficiently stacked when not in use, and includes opposing sidewalls 110a, a rear wall 110b and a front wall 110c. Proximate the top edge of each sidewall 110a and facing the interior of the cage body is channel 112 having a channel width “W” and depth “D” (see
To permit slidable removal and replacement of the top panel, the top edge of front wall 110c is situated below the channel so as not to obstruct movement of the top panel. Rear wall 110b may also be constructed to have its top edge below the channel to permit sliding of the top panel from either the front or rear. More preferably rear wall 110b has a length generally equal to that of the sidewalls and provides a backstop when slidably inserting the top panel. The rear wall 110b may further include a similar channel 112 to further assist in trapping the top panel.
Referring to
Front wall 110c may further include provisions for a water bottle. For instance, front wall 110c may include spout hole 116. Spout hole 116 is preferably situated at about a 58° downward angle to allow one-way passage of the spout through the wall. Two additional holes 118 may be provided to allow for a restraint, such as a spring, cord or bungee, to support the upper end of the water bottle when in position. Preferably, holes 116 and 118 are situated within front wall 110c such that the rodent within the cage can easily access the water spout when desired.
In a preferred embodiment, opposing sidewalls (i.e. sidewalls 110a or front wall 110c/rear wall 110b) carry a plurality of corresponding evenly spaced through-holes proximate the bottom end of the cage body. A plurality of acrylic rods 120 is secured within respective corresponding opposing holes so as to form a floor. Each successive rod is arranged generally in parallel spaced relation with its preceding rod so as to form a lateral space 121 between adjacent rods. Lateral spaces 121 allow soiled bedding to pass between the rods during cleaning of the cage, while the rods are spaced in close enough proximity to one another to prevent the rodent from slipping between the rods or otherwise escaping the cage during the cleaning process. In this manner, the bedding may be refreshed without requiring handling of the rodent or removal of any tethered connections mounted onto the rodent. While disclosed as cylindrical rods 120, it is anticipated that one skilled in the art would understand that any suitable shape flooring could be used, such as tubes or bars having a square or rectangular cross-section.
Slidable top panel 130 is proportioned to include a thickness “T” such that the panel snugly slides within the channel 112 defined by sidewalls 110a with the top panel secured within the channel thereby preventing or minimizing horizontal movement of the panel. In this manner, a rodent within the cage cannot jump out of the cage when the top panel is in place. To allow research equipment to be tethered to the rodent within the cage, the top panel is equipped with one or more through-holes 134. In a preferred embodiment, at least one through-hole is adapted to be generally oblong in shape and intersect with an edge of top panel thereby forming a slotted indentation 132. Ideally, the edge of top panel 130 incorporating indentation 132 is directed into channel 112 so that the indentation 132 rests against rear sidewall 110b, with tethered leads, tubing, or other lines passing through the indentation opening. These research materials are retained in place by the three edges forming the indentation and the rear wall 110b. When cleaning the cage, the top panel may be withdrawn from the channel 112 without requiring handling of the rodent or detachment of the tethers. New bedding material can be dropped into the cage body from the open top followed by slidably replacing the top panel when complete. The remainder of through-holes 134 provide for extra ventilation and air circulation.
Tray 150 includes a tray bottom 150a and integral tray sidewalls 150b. Tray 150 is sized so that cage body 110 sits within the tray when the rodent cage is in use. In a preferred embodiment, tray sidewalls 150b are proportioned such that their upper ends extend at least above the height of the floor rods 120 situated within the cage body. Thus, when cleaning the cage and refilling with bedding, tray 150 collects all of the soiled bedding for disposal.
The rodent cage 100 of the present invention provides a more efficient and safer method of cleaning a rodent cage during an on-going experiment. Referring to
While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.
