RU198263U1 - DEVICE FOR FIXING LABORATORY ANIMALS WITH LOCAL RADIATION OF THE BRAIN - Google Patents

Abstract

The utility model relates to the field of experimental biology and medicine and expands the arsenal of technical devices for the immobilization of experimental animals, mainly rats, when simulating local radiation exposure to targeted areas of the brain. The device for fixing laboratory animals is made of inert material and consists of (Fig. 1): a U-shaped rectangular platform 6 with two sides, and on the sides of the sides there are two semicircular slots 4 for fixing the limbs and upper incisors, lodgement 1, and on the lodgement 1 there is a round hole 2 for the dorsal region of the head, and in the end part of the cradle 1 there are two-blade metal clips 3 with textile cords (not shown in the illustration), two on the long part of the cradle 1 and one on the wide part of the cradle 1. For vertical irradiation of the cradle, the device additionally equipped with a support 5 with grooves 7. The use of the device allows to achieve reliable immobilization of laboratory animals without anesthesia, affecting radiobiological effects, to act with beams of ionizing radiation on the studied areas of the brain, as well as for other manipulations. The device does not require large manufacturing costs and is easy to use. 4 ill.

Description

The utility model relates to the field of experimental biology and medicine as a technical tool for fixing laboratory animals, mainly rats, when modeling local radiation exposure on target zones of the brain.

Radiotherapy of malignant neoplasms of the human brain may be accompanied by radiation damage to critical neurogenesis zones adjacent to the tumor focus, responsible for reparative processes in the nervous tissue and affecting the neurological capacity and cognitive functions of patients. Zones of neurogenesis occupy limited areas of the brain and are located mainly in the rostral section of the lateral ventricles and the dentate gyrus of the hippocampus. Experimental modeling of radiation damage to neurogenesis zones with subsequent evaluation of the effectiveness of neuroprotective drugs and cell therapy to stimulate recovery processes in the nervous tissue is one of the necessary stages of preclinical studies of methods for the correction of neuropsychiatric status indicators in patients with brain tumors.

Reliable fixation of the head of a laboratory animal is necessary to ensure precise radiation exposure to target areas of the brain. To date, a number of devices are known for fixing laboratory animals during various manipulations.

A device for fixing experimental animals is known (SU 1242156 A1, 07/07/1986), consisting of a semi-cylindrical chamber with a head and a tail mounted on a flat base and having a cutout in the head allowing access to the animal's head. In this case, rigid fixation of the animal as a whole and its head in particular is carried out using a system of latches and slats.

The disadvantages of this device are the complexity of its execution and the bulkiness of the design, as well as the possible compression of the upper respiratory tract of the animal.

A device for fixing laboratory animals (SU 1123680 A1, 11/15/1984) is known, which is a platform on a tripod, equipped with a movable carriage with grippers for the hips and pelvic grip brackets, a fixed carriage with grippers for the shoulders and shoulder grip brackets and a removable headband with nape fixator, horizontal head restraints and a movable open mouth latch.

The disadvantages of this device are the complexity of its execution and the bulkiness of the design, as well as the compelled animal causing a number of inconveniences when used, which can provoke a stressful reaction in it and, therefore, distort the results of the experiment.

A known method of fixing small laboratory animals on the operating table (RU 2303421 C1, 07.27.2007). The method consists in placing an anesthetized animal on a device containing a base with stand supports and guides repeating the contours of the animal placed on the back of this type of animal with front and hind legs and head spread out to the sides. Then they wrap limbs, torso and head together with adhesive tape guides.

The disadvantage of this method of fixation is the mandatory anesthesia of the animal and the lack of free access to the head.

A device for fixing laboratory animals (RU 2375012 C1, 12/10/2009) is known, which contains a base of a homogeneous material transparent to the radiation used. A recess is made along the base for the animal, on the sides of which there are elevations that limit the field of view. In the region of limbs, projections are made along the edges of the base and clamps with clamps are installed. For the plane fixation of the animal there is a clamping bar with the possibility of fixing it in the head and tail of the device.

The disadvantage of this device is the lack of reliable fixation of the head.

A known container for fixing a laboratory animal (RU 2510166 C1, 03/27/2014). The container for fixation contains an elongated nose with a hole for breathing, cutouts for the tail and limbs. In addition, the container is additionally equipped with extendable supporting platforms and adjustable clamps for the limbs, while the clamps for the limbs are made in the form of removable clamps in the form of a hollow cylinder with soft gaskets inside and have the ability to move in three planes. The rear wall is removable and has the ability to move horizontally to resize the container. Slots for the limbs are made in the side walls and are equipped with paired removable restrictive straps with a semicircular cut at one end.

The disadvantage of this device is the lack of reliable fixation of the head.

A device is known for fixing laboratory animals during radiological studies (RU 2547719 C1, 04/10/2015). The device includes a base, rear, front and side walls forming a box. At the same time, vertical and horizontal grooves are made on the side walls inside the box. In the vertical grooves a movable partition is placed, providing the ability to change the length of the box. A movable box lid is introduced into the horizontal grooves, allowing you to change its height. The rear wall is made in the form of a door mounted on hinges. The front wall has an opening for the animal’s head and consists of two parts, the upper part of the wall being movable and having an opening. There are ventilation holes in the side walls. In the back of the base of the box there are holes for the toilet. On the surface of the base of the device from the outer side of the front wall there is a movable table with arcuate wings and a movement mechanism fixed on it. The flaps on the side of the box have cone-shaped petals, providing a density of coverage of the head of the animal from the side of the neck. On the basis of the device, on both sides of the movable table, are placed sites for the collimator. They have the ability to change the height and tilt of the collimator.

The disadvantage of this device is the inability to provide rigid fixation of the head of the animal.

A device for gentle fixation of small laboratory animals is known, which allows manipulations with a selected part of the body surface for preclinical studies (RU 2633781 C1, 10/18/2017). The device comprises a transparent housing, a rear housing plug and a movable funnel-shaped plug, movable along the axis of the housing, made of polycarbonate, attached to it. The case has a rectangular shape, equipped with a flat platform with a removable cover. The rear plug is made movable, rectangular holes with dimensions of 15 × 60 mm are made on the upper surface of the housing in the head and the funnel-shaped front movable plug. These openings allow access to various selected areas of the animal’s body, including the head.

However, the known device does not allow to reliably restrict the movement of individual parts of the body, therefore, it is not suitable for targeted exposure to ionizing radiation on a specific area of the brain.

A device for fixing the head of laboratory animals is known (RU 2629777 C2, 07.26.2017). The device contains an earplug, a muzzle, and a micromanipulator. The earplug consists of micrometric mechanisms of earplugs, tips of earplugs, safety balls, tips of earplugs and support for earplugs. The muzzle retainer consists of lambs for attaching the upper jaw incisors, the upper jaw incisal retainer, the nose and lower jaw retainer bush, the muzzle retainer wheel, springs, the muzzle support retainer frame, and the micromanipulator consists of vertical and horizontal micrometric mechanisms with manual feed and vertical and horizontal feed.

The disadvantage of this device is the technical complexity of its implementation and use, as well as the bulkiness of the design. Fixing the animal in this device takes a lot of time and cannot provide a sufficient level of reproducibility of the results.

As a result of the analysis of the listed sources of information, it was concluded that none of the above-mentioned known devices can be considered the closest analogue and chosen as a prototype, since the claimed utility model not only has cardinal differences from them in terms of design, but also provides a completely different way placement and fixation of the animal.

The technical result of the claimed utility model is the creation of an easy-to-use and reliable device for fixing the head of laboratory animals, allowing local exposure to ionizing radiation to the “target” zones of the brain, as well as other manipulations with experimental animals under conditions of their immobilization.

The specified technical result is solved by the fact that the device is made of an inert material and consists of a U-shaped rectangular platform with two sides, and on the sides of the sides there are two semicircular slots for fixing the limbs and upper incisors, lodgement, and there is a round hole for the dorsal region on the lodgement the head, and in the end part of the lodgement there are bilobate metal clips with textile cords, two on the long part and one on the wide part of the lodgement. For irradiation in the vertical orientation of the animal, a stand with grooves is used.

To irradiate local areas of the rat’s head with protons or carbon ions, the beams of which are horizontally directed, the base with the animal fixed on it is rotated 90 ° and inserted vertically into the grooves of the stand, placing the dorsal region of the animal’s head perpendicular to the direction of action. In this case, focused beams of corpuscular radiation are directed exactly to the marker of the area of the rat’s head corresponding to the topographic location of the target areas of the brain, including neurogenesis zones [Paxinos G., Watson C. The rat brain in stereotaxic coordinates. Compact third edition // Acad. Press, San Diego. 1997].

To influence the animal’s brain with radiation directed from top to bottom (photons, electrons, etc.), the platform with the animals fixed on it is placed in the installation for irradiation horizontally, with the dorsal surface of the animal’s head up.

The utility model is illustrated by a detailed description and illustrations, which depict:

FIG. 1 - diagram of the device: 1 - lodgement; 2 - a hole with a projection on the dorsal region of the head of the animal; 3 - two-leaf metal clamps; 4 - semicircular cuts for fixing the limbs and upper incisors; 5 - an additional support for irradiation in the vertical orientation of the tool tray with grooves 7; 6 - U-shaped rectangular platform 6 with two sides.

FIG. 2 is a drawing of a device with the indicated dimensions in mm: A is a front view of the device in an upright position; B - profile view of the device; B - top view of the stand for the device

FIG. 3 is a general view of an assembled device for immobilizing an animal.

FIG. 4 is an example of fixing a laboratory rat in a device: a) a bottom view with fixation of the limbs and upper incisors of the head with a soft textile cord, b) a top view; in the projection of the hole on the lodgement, a mark is applied for the effect of ionizing radiation on the neurogenesis zone in the rostral section of the lateral ventricles.

The device for fixing laboratory animals is made of inert material and consists of (Fig. 1): a U-shaped rectangular platform 6 with two sides, and on the sides of the sides there are two semicircular slots 4 for fixing the limbs and upper incisors, lodgement 1, and lodgement 1 has a round hole 2 for the dorsal region of the head, and bilobate metal clips 3 with textile cords (shown in the illustration) are two on the long end of the lodgement 1, two on the long part of the lodgement 1 and one on the wide part of the lodgement 1. For vertical irradiation of the lodgement the device is additionally equipped with a stand 5 with grooves 7.

The device operates as follows.

The animal in the supine position on the inside of the U-shaped platform 6 (Fig. 1) is placed on the lodgement 1 with a round hole 2. Anesthesia of the animal is not required. Fixing loops from a textile cord are put on the animal’s extremities and stretched to the sides through slots 4 at an angle of approximately 45 ° and securely fixed in metal bilobate clamps 3. The animal’s head is fixed by hooking the stretch loop over the upper incisors of the rat and securing the cord in the petal latch 3 located on the front of the lodgement opposite the animal’s head so that the frontotoparietal region of the head is located above the hole in the platform 2. The topographic location of the brain zones and their projection onto the skull surface is determined by the stereotactic coordinates of the Bregma level and marked with a marker on the depilated scalp, which provides high accuracy of radiation exposure. The reproducibility of stacking accuracy is ± 1mm. Then, depending on the method of irradiation and the type of radiation, the platform 6 with the animal fixed in it is placed vertically in the grooves 7 on the stand 5, or horizontally on the sides of the platform.

The device allows you to irradiate the head of rats with a body weight of from 150 to 500 g by adjusting the length of the cords so that the dorsal region of the head of the animal is located under the cutout of the platform.

Execution example.

For the experiment, a device was made (Fig. 2, a, b, c, Fig. 3) of a U-shaped rectangular platform 6 with dimensions of 174 x 297 x 10 mm from plexiglass with two sides (Figs. 3, 4) 35 mm high the long sides of the platform and a hole 2 with a diameter of 30 mm for the parietal part of the animal’s head in the front of the lodgement. For the vertical arrangement of the platform, a support 5 with dimensions of 174 x 152 x 40 mm was used. Loops of textile material were put on the extremities of the rat and the animal was placed in a supine position on lodgement 1 (Fig. 4, A) so that the head of the individual was located above the round opening of the platform. For this, the animal’s extremities were stretched at angles of approximately 45 ° and the loops were fixed in the clips 3. The fifth loop was put on the upper incisors of the rat and fixed in the corresponding clip 3 located on the front of the tool tray 1. In the projection of the hole 2 on the tool tray, a marker was applied for exposure to ionizing radiation (Fig. 4, B). To irradiate the parietal region of the head of the rat with a proton beam, a lodgement 1 with the animal fixed on it was inserted vertically into the grooves 7 of the stand 5. For local exposure to the parietal part of the head of the rat with gamma-quanta, platform 6 with the immobilized animal was placed horizontally in the corresponding irradiation unit with the head dorsal upward.

Thanks to the proposed design, the utility model allows:

to achieve reliable immobilization of laboratory animals without anesthesia, affecting the radiobiological effects,

to act with beams of ionizing radiation on the studied areas of the brain, as well as for other manipulations.

The device is easy to use and does not require large expenses in its manufacture.

Claims (2)

1. A device for fixing laboratory animals with local brain irradiation, characterized in that it is made of an inert material and consists of a U-shaped rectangular platform with two sides, and there are two semicircular slots on the sides of the sides for fixing the limbs and upper incisors, lodgement moreover, on the lodgement there is a round hole for the dorsal region of the head, and in the end part of the lodgement there are bilobate metal clips with textile cords - two on the long part and one on the wide part of the lodgement. 2. The device according to claim 1, characterized in that it is equipped with a stand with grooves for vertical irradiation of the lodgement.

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