RU2432902C2 - Problem chamber for measurement of individual level of cognitive ability of rats - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to experimental physiology and is intended for measurement of individual level of cognitive abilities of laboratory animals. Problem chamber consists of two modules. Upper module is made in form of truncated hexagonal pyramid from organic glass with six outlet canals, covered with sloping hinged doors with magnets, reeds, photodiodes above each chamber door, which are switched on at purposeful pushes of sloping door inside by head or paws of tested rat during exit or attempt to open blocked door, with buzzer of sound conventional stimulus supply. Lower module represents electrode floor for aversive electric stimulation of animal's paws.

EFFECT: invention ensures increased accuracy of estimation of individual level of cognitive abilities in process of motivated by problem situation search for exit from the chamber.

4 dwg

Description

The invention relates to experimental physiology of behavior and is intended to measure the individual level of cognitive abilities of rats in the study of evoked search activity in the problem chamber of Grigoriev.

The problem camera we have proposed is known in which individual quanta of the search behavior are fixed on a paper tape of a recorder or in a PC memory [3]. The design of the chamber is a hexagon made of plexiglass with vertical side walls, with an electrified grating floor connected to an electronic pulse stimulator - a source of aversive electrodermal irritation of rat paws. The chamber is covered with a transparent ceiling with a centrally located closing hatch for placing the animal in the chamber. The camera exits cover suspended sensory doors with magnets and reed switches in the side wall - sensors for touching the door from the inside. A detailed description and installation diagram is presented in our publications [2, 4, 5, 6].

The disadvantages of this device are:

1) the impossibility of a highly objective assessment of the quality of the search activity of productive and erroneous runs from the problem camera without recording the search behavior of the camera due to the lack of visual markers of the effective run - the result of a correctly made decision or an erroneous run - the result of an incorrect decision;

2) the presence of artifacts due to the slight displacement from the equilibrium position of the vertical door to the outside of the chamber from tangentially directed touches, casually along the tangent (non-essential), when the reed switches are triggered and the recorders record unfocused touches of the body with the side or tail of the animal running past the door;

3) the absence of a stable stable initial overlay of the door, sensitive only to significant deliberate shocks, having sufficient intensity and strength, which are provided by targeted, close to perpendicular hits with the head or front paws;

4) the difficulty of eliminating olfactory marks from the previous animal due to the solidity of the camera device and the inability to penetrate inside for cleaning;

5) the absence in the chamber of the device of a sound conditioned stimulus for preliminary development of a conditioned reflex of active avoidance (URAI);

6) the absence of guiding side walls in the cover around the central hole, providing a standard direction for the animals to run when placed in the chamber.

A new device is proposed - a problem camera (a problem environment of varying complexity) for quantitative assessment of an individual level of cognitive abilities in the process of finding a way out of a camera motivated by a problem situation.

The device operates as follows.

Figure 1 shows the problem chamber, which is a truncated hexagonal pyramid with walls tilted inward at an angle of 75 °. Such an inclination inward provides a stable and stable fit of the transparent suspended door (1) to the inclined wall of the chamber due to downward, pressing it gravitational forces. That is why the camera is given a conical shape.

This eliminates the false triggering of the reed switches (2) when touching the tail or side of a running animal to the doors. Figure 2 shows the reed switches (2), which only trigger targeted deliberate direct hits with the head or front paws when the magnet (10) glued to the door closes a tight contact when approaching the reed switch. The reed switch clearance is no more than 3-4 mm.

Figure 1 shows the reed switches. For effective video surveillance of relatively quick runs and touches, the reed switches (2) close the electric circuit, - Fig. 4 shows a diagram in which above each door there is an LED (3) with its door number, the first flash of which in each search cycle indicates correctly received the decision and exit of the animal from the chamber, and all subsequent ones are about erroneous decisions. Thus, all elements of search behavior are objectively recorded by a video camera. Figure 2 shows the inclined walls of the chamber. The second function of the inclined walls of the chamber is that the inclination of the door makes it easier for animals to exit the chamber into the surrounding space because raising the door with the animal’s head is tangential, which makes it easy to unidirectionally lift and open the door from the inside of the chamber and the inability to open it from the outside . To facilitate orientation and the choice of the direction of the pace, the doors are left transparent, the walls of the chamber, and the gaps of which they are located, are painted black and opaque (4). Thus, the animal is presented with six directions for running. The blocked door is partially obscured by the blocking transverse bar (5) shown in Figs. 1, 2, which is an auxiliary reference point for the animal looking for a way out. In the previous version, this hint was absent.

In order to exclude artifacts that the experimenter can make, around the central hole for placing the animal in the chamber, guide lateral walls (6) are made, shown in FIG. 1, which always ensure only the unidirectional entry of the animal into the chamber, which standardizes the decision-making step for choosing the direction of the next run . The camera is covered by a transparent ceiling (7), which excludes vertical search activity of the animal (column ascents in the form of a rack), with a hole in the center that is closed by a retractable cover (8) inserted into the guide grooves.

To exclude the orientation of animals in the chamber according to olfactory marks, it is made collapsible and consists of two halves: the lower one, shown in figure 3, - the electrode floor (11) connected to the pulse stimulator (12) with a circuit breaker (13), and the upper one removable half, that is, the actual camera shown in Fig.1. These system changes allow you to quickly wet-clean the camera and its floor after each next test.

To supply a conditioned stimulus, a sound source was introduced into the device system - an EFM-250A buzzer, 80 dB, 4 ± 0.5 kHz, 3.9 V (9).

The technical result of the invention is the modernization and improvement of the device for testing rats after the developed one-sided URAI in the conditions of objective video recording of the search behavior.

Literature

1. Grigoriev N.R. A method for determining search activity in an experiment. A.S. No. 1776385. 1992.

2. Grigoriev N.R. A method of researching search activity and search abandonment. // Journal. higher nervous activist - 1996. - T. 46, No. 2. S. 400-405.

3. Grigoriev N.R., Plastinin M.L., Brush A.A. A method for recording and analyzing indicators of search activity of animals in a problem chamber. Description of the invention to the patent of the Russian Federation No. 2204943. Bull. 3. 2002.

4. Grigoriev N.R. Typological features of rat behavior. / N.R. Grigoriev, T.A. Batalova, E.F. Kirichenko, A.A. Sergievich, G.E. Cherbikova. // Grew. fiziol. journal - 2007. - T.93, No. 8. S.817-826.

5. Grigoryev N.R. Experimental research model for the search of activity and cognitive abilities in rats. / N.R. Grigoryev, G. E. Cherbikova. // International Journal of Psychophysiology. - 2008. - Vol.69, No. 3. P.250.

6. Grigor'ev N.R. Typological Features in the Behavior of Rats. / N.R. Grigor'ev, T.A. Batalova, G.E. Cherbikova. // Neuroscience and Behavioral Physiology. - 2008 .-- Vol.38, No.6. P.597-603.

7. Shames A.L. Behavior. Perception. Thinking: the problems of creating artificial intelligence. M., 2004.

Claims (1)

A problem camera for measuring the level of individual cognitive abilities of rats when studying the behavior of finding a way out of a problem situation in a video environment, consisting of two modules: the top one in the form of a truncated hexagonal pyramid made of plexiglass, which provides tilt inside the camera of the side walls, with six output channels covered by inclined hanging doors with magnets, reed switches, photodiodes above each camera door, which turn on with targeted shocks inside the head or paws of the test Rysy inclined door when leaving or trying to open the locked door with a buzzer sound the conditioned stimulus and lower module - electrode for sex aversive electrostimulation of animal paws.

Images