ANIMAL MODELS FOR DEPRESSION PROCEDURE AND PROJECT REPORT FOR PHARMACY
Animal models serving in research may have an existing inbred or induced disease or injury that is similar to a human condition Animal model allows researchers to investigate disease state in ways which would be inaccessible in a human patient, performing procedures on the non human animal, that imply a level of harm that would not be considered ethical to inflict on a human.
ANIMAL MODELS FOR DEPRESSION:
• DESPAIR BASED
1. FORCED SWIM TEST
2. TAIL SUSPENSION TEST
• REWARD BASED
1. OPEN FIELD MODEL
• ANXIETY BASED
1. ELEVATED PLUS MAZE
2. DARK/LIGHT BOX
FORCED SWIM TEST:
Behavioral despair was proposed as a model to test for antidepressant activity by Porsolt .It was suggested that mice or rats forced to swim in a restricted space from which they cannot escape are induced to a characteristic behavior of immobility. This behavior shows a state of despair which can reduced by several agents which are therapeutically effective in human depression.
MATERIAL USED:
For rats, Plexiglass cylinder with a diameter of 20 cm and height of 40cm is used .and for mice cylinder with 20cm diameter and 25cm height is used. A standard antidepressants drug and reference antidepressant drugs are tested by this model.
PROCEDURE:
Male rats weighing 160–180 g are used. They are brought to the laboratory at least one day before the experiment and are housed separately in Makrolon® cages with free access to food and water. They are individually forced to swim inside a vertical Plexiglas cylinder (height: 40 cm; diameter: 20 cm, containing 15 cm of water maintained at 25 °C. Rats placed in the cylinders for the first time are initially highly active, vigorously swimming in circles, trying to climb the wall or diving to the bottom. After 2–3 min activity begins to subside and to be interspersed with phases of immobility or floating of increasing length. After 5–6 min immobility reaches a plateau where the rats remain immobile for approximately 80% of the time. After 15 min in the water the rats are removed and allowed to dry in a heated enclosure (32 °C) before being returned to their home cages. They are again placed in the cylinder 24 h later and the total duration of immobility is measured during a 5 min test. Floating behavior during this 5 min period has been found to be reproducible in different groups of rats. An animal is judged to be immobile whenever it remains floating passively in the water in a slightly hunched but upright position, its nose just above the surface. Test drugs or standard are administered one hour prior to testing.
PARAMETER RECORDED:
1. CLIMBING(UPWARD MOVEMENT)
2. ACTIVE SWIMMING
3. FLOATING
EVALUATION:
Duration of immobility is measured in controls and animals treated with various doses of a test drug or standard. Antidepressant drugs, but also stimulants like amphetamine and caffeine, reduce duration of immobility. Dose-responses can be evaluated.
CONCLUSION:
A Porsolt forced swim model is used to test the antidepressant activity in rat or mice It is made up of glass material and plastic material which can easily be prepared .It can easy to construct and handle as compared to other model .The forced swim test model is more convenient and cheep. This model does not require any type of software .It doesn’t cause any harm to the test animal. This model required parameters i.e. climbing, swimming, and floating which can easily be measured. This model provides the facilities of repeating the test for number of time with different doses.