Screening Methods for behavioural and muscle Coordination

Screening Methods for behavioural and muscle Coordination

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  Mrs. Pradnya N.Jagtap Ms. Sayali S. Chavan Department of Pharmacology PDEA’s SGRS College of Pharmacy Screening of Drugs for Behavioural and Muscle Coordination
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  Screening Methods forbehavioural and muscle Coordination a) Motor activity and behaviour 1. Method of intermittent observation 2. Open field test 3. Hole board test 4. Combined open field test b) Test for muscle coordination 1. Inclined plane method 2. Chimny test 3. Grip strength 4. Rotarod method
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  Motor Activity& Behaviour 1.Method of intermittent observations Purpose Tostudy stimulant and sedative drugs by changing animal behavior after adm. Procedure- • Mice weight-25 g ,12 animals are divided into group of 3 mice. • For testing sedative activity, the mice are injected after 10 min s.c with 0.5 mg/kg methamphetamine. • For testing stimulant activity, the mice are treated with 800 mg/kg paraldehyde. • each group is placed into a glass jar of 12 cm diameter and 20 cm height which in turn are placed in a wooden box of 130 50 30 cm & start observation. • amphetamine treated mice count between 120 to 150 and sedative drugs shows decrease in counts.
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  2. Open fieldtest Purpose- • To assess the activity of sedative or stimulant drugs. Procedure- • The rats are observed in a square open field area (68 68 45 cm) equipped with 2 rows of 8 photocells, sensitive to infrared light, placed 40 and 125 mm above the floor. • Measurements are made in the dark in a ventilated, sound-attenuating box. • Interruptions of photocell beams can be collected by a microcomputer and Interruption of light beams as a measure of movements of ratsor mice in a cage.
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  Purpose • The evaluationof certain components of behaviour of mice such as curiosity or exploration. They used an open field with holes on the bottom into which the animals could poke their noses. Procedure • Mice weight between 18 to 22 g are used. • The hole-board has a size of 40 × 40 cm. Sixteen holes with a diameter of 3 cm each are distributed evenly on the floor. • The board is elevated so that the mouse poking its nose into the hole. • Nose-poking is thought to indicate curiosity and motility is measured in addition by counting interruption of light beams. 3. Hole Board test:
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  Purpose • The simultaneousdetermination of locomotion and curiosity by using a modification of the hole-board test and a photo-beam system. Procedure • The animal is tested individually in an automated open-field box which consists of a black Plexiglas cage (35 35 20 cm) with a post (8 8 20 cm) in the centre of the cage. • Two evenly spaced photo cell beams perpendicular to the wall and 2 cm above the floor divide the box into 4 compartments. • Every photo cell beam interruption is registered automatically as an activity count. • 30 min. after i.p and 60 min. after oral administration of the test compound the animal is placed into the cage and the behaviour recorded for a period of 5 min. 4. Combined open field test:
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  1. Inclined planemethod procedure- • Male mice with a body weight between 20 to 30 kg are used. • The plane consists of two rectangular plywood boards connected at one end by a hinge. One board is the base, the other is the movable inclined plane. A rubber mat with ridges 0.2 cm in height is fixed to the inclined plane which is set at 65 degrees. • The test compound or the standard are administered to groups of 10 mice either i.p. or s.c. or orally. 30, 60 and 90 min thereafter, the mice are placed at the upper part of the inclined plane and are given 30 s to hang on or to fall off. • Purpose - The inclined plane method is used to assess skeletal muscle relaxation. Test For Muscle Co-ordination
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  2. Chimney Test: Purpose- •A simple test for assessing the tranquilizing and muscle relaxant activity. Procedure- • Male mice weighing between 16 to 22 are used. • Pyrex-glass cylinders 30 cm long are required. • The internal diameter varies with the animal’s weight: for mice weighing 16 to 18 g, the diameter is 22 mm, for mice weighing 18 to 20 g, 25 mm; for mice weighing 20 to 22 g, 28 mm. • Each tube has a mark 20 cm from its base. Initially, the tube is held in a horizontal • position. At the end of the tube, near the mark, a mouse is introduced with the head forward.
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  • When themouse reaches the other end of the tube, toward which it is pushed if necessary with a rod, the tube is moved to a vertical position. • Immediately, the mouse tries to climb backwards and performs coordinated movements similar to an alpinist to pass a chimney in the mountains. • The time required by the mouse to climb backwards out at the top of the cylinder is noted.
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  3. Grip Strengthtest: Purpose • The test is being used to assess muscular strength or neuromuscular function. Procedure- • Male or female mice with an average weight of 22 g are used. • The animals are exposed to a horizontal thin threat or metallic wire suspended about 30 cm into the air which they immediately grasp with the forepaws. • The mouse is released to hang on with its forelimbs. Normal animals are able to catch the threat with the hind limbs and to climb up within 5 s. • After oral or subcutaneous administration the animals are tested every 15 min. Animals which are not able to touch the threat with the hind limbs within 5 s or fall off from the threat are considered to be impaired.
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  4. Rotarod method Purpose- Procedure– • Male mice with an weight between 20 and 30 g are used. • The apparatus consists of a horizontal wooden rod or metal rod coated with rubber with 3 cm diameter attached to a motor with the speed adjusted to 2 rotations per minute. • The rod is 75 cm in length and is divided into 6 sections by plastic discs, thereby allowing the simultaneous testing of 6 mice. The rod is in a height of about 50 cm above the table top in order to discourage the animals from jumping off the roller. • The test is used to evaluate the activity of drugs interfering with motor coordination and muscle activity.
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  • Cages belowthe sections serve to restrict the movements of the animals when they fall from the roller. • Only those animals which have demonstrated their ability to remain on the revolving rod for at least 1 minute are used for the test. • The test compounds are administered intraperitoneally or orally. • 30 min. after intraperitoneal or 60 min after oral administration the mice are placed for 1 min on the rotating rod. • The number of animals falling from the roller during this time is counted.