SOP Actophotometer by Dr. Alisha Raj. ..

It's a standard operating procedure of Actophotometer

1. Actophotometer (Standard Operating Procedure) Presenter: Dr. Alisha Raj (JR3) Moderator: Dr. Ashish Dixit (SR) Peer support: Dr. Rashmi Chandra (JR3) Dept. of Pharmacology & Therapeutics King George’s Medical University, Lucknow, UP, India-226003 Email id: [email protected] 1 Dr. Alisha Raj 2-May-2025

2. Contents Introduction Principle Components Standard Operating Procedure Precautions Applications Advantages & Limitations Summary 2-May-2025 Dr. Alisha Raj 2

3. Specific learning objectives- By the end of this teaching learning session, my co-learners will be able to: Describe the parts of actophotometer Explain principle of actophotometer Explain the standard operating procedure Enumerate drugs used in actophotometer Enumerate the application of a ctophotometer Dr. Alisha Raj 3 2-May-2025

4. Introduction Acto photo meter “ Acto -" Greek word aktos activity or movement “ photo -" Greek word phōs light . "- meter " Greek word metron measuring instrument 2-May-2025 Dr. Alisha Raj 4

5. Introduction Used to measure the locomotor activity and behaviour in laboratory animals, particularly rodents, in response to pharmacological interventions Locomotor activity serves as an indicator of alertness or CNS activity Helps to assess CNS stimulant or depressant properties of drugs 2-May-2025 Dr. Alisha Raj 5

6. Principle Based on the principle of P hotoelectric cell S eries of light beams are placed across the chamber As the animal moves inside the chamber, it interrupts the light beams Each interruption is counted as a movement and displayed on a digital counter This count reflects the animal’s locomotor activity 2-May-2025 Dr. Alisha Raj 6

7. CNS stimulants - increased movement more beam breaks higher score 2-May-2025 Dr. Alisha Raj 7 CNS depressants - increased movement more beam breaks higher score

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9. Instrument ID : KG/PH/PG1/012 2-May-2025 Dr. Alisha Raj 9

10. Part Description Function 1. Enclosed Chamber rectangular or circular transparent box made of Plexiglas or acrylic Provides a safe and standardized space to move freely without escaping 2-May-2025 Dr. Alisha Raj 10 Components

11. 2-May-2025 Dr. Alisha Raj 11 Part Description Function 2. Photoelectric Sensors / Infrared Beams Pairs of light emitters and detectors (placed on opposite walls) form a grid of light beams Detect movement by counting how many times the animal breaks the light beam

12. 2-May-2025 Dr. Alisha Raj 12 Part Description Function 3. Digital/Analog Display Unit Screen or counter showing a numerical readout Shows the total locomotor activity count during a set time

13. 2-May-2025 Dr. Alisha Raj 13 Part Description Function 4. Control Panel / Timer Buttons or dials to reset counter , and start/stop the test control test conditions and record consistent data

14. 2-May-2025 Dr. Alisha Raj 14 Part Description Function 5. Power Supply Unit Electrical input Powers the sensors, counting unit , and any digital interface X axis sensor cord Y axis sensor cord Z axis sensor(optional) On/Off switch Main supply Fuse RS 232 cord

15. Other models of Actophotometer 2-May-2025 Dr. Alisha Raj 15

16. Activity cage – Arena, grid floor Photo sensors Tray Control panel- Control switch & indicator 4-digit digital counter Reset button Shock button, meter & indicator 2-May-2025 Dr. Alisha Raj 16

17. Step-wise Protocol Step Procedure Purpose 1. Acclimatize the animal to the lab environment for 30–60 minutes Minimizes stress and normalizes behaviour 2. Switch on the actophotometer and allow it to warm up for 5–10 minutes Ensures stable functioning and accurate beam detection 3. Check calibration by waving an object through beams or using a known control Confirms all sensors are working and activity counts are valid 4. Place the rodent inside the chamber and close the lid Begins the test under standardized condition 5. Record the baseline activity for a fixed time (usually 5 minutes) Establishes control (normal) locomotor activity for comparison 2-May-2025 Dr. Alisha Raj 17

18. Step Procedure Purpose 6. Administer the test drug (e.g., diazepam, amphetamine) intraperitoneally or orally Introduces the CNS-active agent to observe its effect 7. Wait for 30–60 minutes depending on drug onset time Allows the drug to take effect before testing activity 8. Place the animal back in the chamber and again record activity for the same time period Measures post-drug activity to assess stimulant or depressant action 9. Clean the chamber between animals using mild disinfectant Prevents odor interference in subsequent tests 10. Repeat for remaining animals (usually 6 per group) Ensures reproducibility and statistical reliability 2-May-2025 Dr. Alisha Raj 18

19. Standard operating procedure Weigh & number the Rat/Mice Turn on the equipment Check & sure that all the photocells are working for accurate reading Place individually each Rat/ Mice in the activity cage for 10 min Note down the basal activity score 2-May-2025 Dr. Alisha Raj 19

20. Note the difference in the activity, before & after the test drug Reset for the next animal Same procedure is followed for test & standard drugs Electric shock (for a fraction of a second) can be given when animal does not move from one place for a long time Inject the test drug & after 30 mins re-test each mouse for activity scores for 10 mins 2-May-2025 Dr. Alisha Raj 20

21. General reminders Note the difference in the activity, before & after the drug Calculate percent change in motor activity Reset button - used after each animal Electric shock - animal does not move from one place for a long time 2-May-2025 Dr. Alisha Raj 21

22. Observations S. No Weight (gm) Drug dose (mg/kg) Locomotor activity scores for 10 min Percentage change in locomotor activity Basal After treatment 1 2 3 4 5 6 2-May-2025 Dr. Alisha Raj 22

23. Result Reduction in motor activity CNS depressant property Increase in motor activity CNS stimulant property 2-May-2025 Dr. Alisha Raj 23

24. Commonly used drugs CNS depressants : Chlorpromazine hydrochloride (3 mg/kg, ip ) Fluoxetine (10 mg/kg, ip ) Imipramine (10-20 mg/kg, ip ) Phenobarbitone sodium (10 mg/kg, ip ) Alcohol (0.5-2 g, ip , po) CNS stimulants : Caffeine (8-10mg/kg, ip - mice & 30mg/kg, ip - rat) Amphetamine (1.5 mg/kg, ip & 3-5mg/kg, sc , ip - rats ) 2-May-2025 Dr. Alisha Raj 24

25. Precautions Keep the instrument clean & dry Do not the handle the instrument with wet hands Do not touch the grill when the shock strength is on Handle the Perspex box carefully 2-May-2025 Dr. Alisha Raj 25

26. Applications To quantify and assess the locomotor activity in animal models To evaluate the CNS effects of drugs by measuring changes in motor activity To study neurobehavioral studies Acts as Reliable screening tool in preclinical pharmacology 2-May-2025 Dr. Alisha Raj 26

27. Advantages Easy to operate Non-invasive Rapid and cost-effective Detects even slight stimulant or depressant effects 2-May-2025 Dr. Alisha Raj 27

28. Limitations Only measures movement, not anxiety or curiosity Influenced by factors like light, stress, noise Not suitable for large animals 2-May-2025 Dr. Alisha Raj 28

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30. Summary An actophotometer measures locomotor activity in small animals using photoelectric sensors Components: Enclosed chamber, IR sensors, digital display, control panel, power unit Movement interrupts infrared beams, and each interruption counts as one unit of activity To assess the CNS stimulant or depressant effect of drugs and also used for b behavioural studies Easy to use and non invasive 2-May-2025 Dr. Alisha Raj 30

31. Specific learning objectives achieved By the end of this teaching learning session, my co-learners are able to: Describe the parts of actophotometer Explain principle of actophotometer Explain the standard operating procedure Enumerate drugs used in actophotometer Enumerate the application of a ctophotometer Dr. Alisha Raj 31 2-May-2025

32. References Orchid Scientific & Innovative India Pvt Ltd. - Actophotometer book manual. Akshayraj Vanrajbhai C, Thorat VM, Patel VS, Patil KP, Chawla LL. Evaluation of Anxiolytic Activity of Angiotensin Receptor Blockers Using Actophotometer Test in Wistar Rats. Cureus . 2024 Sep 20; Bhosale U, Yegnanarayan R, Prachi P, Zambare M, Somani RS. Study of cns depressant and behavioral activity of an ethanol extract of achyranthes aspera ( chirchita ) in mouse model. Ann Neurosci . 2011 Apr;18(2):44–7. Jarrar Q, Ayoub R, Jarrar Y, Aburass H, Goh KW, Ardianto C, et al. Flumazenil Pretreatment Reduces Mefenamic Acid-Induced Central Nervous System Toxicity in Mice. J Integr Neurosci . 2023 Jul 26;22(4). Kulkarni SK. Handbook of Experimental Pharmacology . 3rd ed. New Delhi: Vallabh Prakashan; 2005 2-May-2025 Dr. Alisha Raj 32

33. THANK YOU! 2-May-2025 Dr. Alisha Raj 33

34. Questions ? What is the principle behind the actophotometer ? Enumerate the parts of an actophotometer and their functions ? How does an actophotometer helps to differentiate between CNS stimulant and CNS depressant activity in animal experiments? What precautions should be taken during the procedure ?