Elevated Plus Maze sop ppt by nitin.pptx

describe working principle, uses, advantages, disadvantages, antianxiety drugs, standard operating procedure of elevated plus maze

1. Elevated Plus Maze By- Dr. Nitin Kumar Singh Junior Resident -1 Department of pharmacology and therapeutics King George’s Medical college , Lucknow

2. Objectives Introduction Measurements Observation Equipment Principle Materials Precautions Troubleshooting Drawback References

3. INTRODUCTION Elevated plus maze test is broadly used for determining anxiolytic properties of drugs in rodents. The test is performed on a plus-shaped apparatus with two open and the two closed arms. The animal is allowed to freely explore the maze while the duration and frequency of entries is recorded. The task is based on approach-avoidance conflict. Approach-avoidance conflict means that the animal is faced with a struggle between a propensity to explore a novel environment and an unconditional fear of high and open spaces. Consequently, an anxiety like state is characterized by increased open arm avoidance, compare to control animals.

4. MEASURMENTS Behavioral parameters measured by- 1.Locomotor activity 2.Anxiety Screening test- 1.Anxiolytic 2.Anxiogenic compounds

5. OBSERVATIONS Parameters to be measured during the next 5 minutes- Entries in open arms. Time spent in open arms. Entries into the closed arms. Time spent in the closed arms. Total arm entries.

6. Observation table S/No. Entries in open arms. Time spent in open arms Entries into the closed arms. Time spent in closed arms Total time spent   Entries into the closed arms. 1. 2. 3. 4. 5. 6.

7. SCORING: Calculate the percentage of time spent in open arms: Total time in open arms​×100 Calculate the percentage of open arm entries: Total arm entries Open arm entries​×100 DATA COLLECTION : Record the observations manually or using stop watch. If using video recording, review the video to verify the observations. DATA ANALYSIS: Compare the behaviour of the test group (e.g., treated with anxiolytic or anxiogenic compounds) with the control group. Analyse the data statistically (e.g., t-test, ANOVA) to determine significant differences.

8. Equipment The EPM apparatus consists of a “ + ” shaped maze elevated above the floor with two opposite positioned closed arms, two oppositely positioned open arms, and a center area. Elevated plus maze has 4 arms at an angle of 90° The plus maze apparatus consists of- Two open (16 × 5 cm for mouse and 50 × 10cm for the rats). Two closed arms (16 × 5 × 12 cm for mouse and 50 × 10 × 40 cm for rats). Entire maze elevated (25 cm for mouse and 50 cm for rats) from the floor.

9. PRINCIPLE The Elevated plus maze (EPM) is a model of anxiety that usually uses rodents as a screening test for anxiolytic or anxiogenic compounds. The model is based on the test animal aversion to open spaces and tendency to be thigmotaxis (a preference to remain near to, or touching, vertical surfaces).

10. MATERIALS Animal/species: Rat/Wistar Sex/Body weight: Either sex/150-250g Syringe/needle: 1ml/preferably 23G Drug: Diazepam (0.5-1 mg/kg, i.p. ) other drugs like alcohol, benzodiazepine, barbiturates etc.

11. PRECAUTIONS Laboratory should be dim lighted and noise free. Animal should be marked properly , to avoid mixing in two groups. Handle the animals with care (minimize the stress and pain to animal). Place the rat at the center of the plus maze, facing towards open field. Video recorder is placed to record the experiment in correct position. After each trial, clean with super hypochlorous water, to prevent a bias based on olfactory cues.

12. TROUBLESHOOTING Infrequently rats or mice run to the edge of the open arms and fall off. When this occurs, the experimenter must rapidly pick the animal up and place it back onto the open arms of the maze. This behavior must be recorded on the data sheet and taken into consideration when the behavioral data are analyzed.

13. Cont. If a noise or movement occurs while rodents are on the open arms of the elevated plus maze, rodents are likely to freeze for an extended period of time. Freezing for an extended period of time would be considered when the time spent on the open arms is more than 30% of the total test time (i.e., more than 100 s).

14. DRAWBACKS On account of being a very popular test, there can be considerable variations in the procedure applied across different laboratories. Time spent on the central platform can create ambiguity in terms of how that time is interpreted.

15. References Medhi B, Prakash A.Practical Manual of Experimental and Clinical Pharmacology:2010Jaypee Brothers.