February 23, 2024

Effect of drugs on locomotor activity using actophotometer

Effect of drugs on locomotor activity using actophotometer

BP408P Pharmacology I Practical / S Y B Pharmacy Notes


To  study  the  central  nervous  system  depressant  property  of  chlorpromazine  on  the locomotor activity of mice using actophotometer


Most of the central nervous system acting drugs influencing the locomotor activities in man and animals. The CNS depressant drugs such as barbiturates and alcohol reduces the motor activity while the stimulants such as caffeine, amphetamines increases the activity. In other words , the locomotor activity can be index of wakefulness of mental activity. The locomotor activity can be easily measured using an actophotometer . which operates on photoelectric cells which are connected in circuit with a counter . when the beam of light falling on the photocell is cut off by the animal, a count is recorded. An actophotometer could have either circular or square arena in which the animal moves. Both rats and mice may be used for testing in this equipment.


Animal: Mice (20-25gm)

Drugs: Chlorpromazine hydrochloride

Equipment : Actophotometer


  1. Weigh the animals and number them
  2. Turn on the equipment and place individually each mouse in the activity cage for 10 min. Note the basal activity score of all the animals.
  3. Inject chlorpromazine and after 30 min re-test each mouse for activity scores for 10 min. Note the difference in the activity before and after chlorpromazine.
  4. Calculate percent decrease in motor activity.

Pharmacology I Practical

  1. Introduction to experimental pharmacology.
  2. Commonly used instruments in experimental pharmacology.
  3. Study of common laboratory animals.
  4. Maintenance of laboratory animals as per CPCSEA guidelines.
  5. Common laboratory techniques.
  6. Study of different routes of drugs administration in mice/rats.
  7. Study effect of hepatic microsomal enzyme inducers on phenobarbitone sleeping time in mice.
  8. Effect of drugs on ciliary motility of frog oesophagus
  9. Effect of drugs on rabbit eye.
  10. Effects of skeletal muscle relaxants using rota-rod apparatus.
  11. Effect of drugs on locomotor activity using actophotometer.
  12. Anticonvulsant effect of drugs by MES and PTZ method.
  13. Study of stereotype and anti-catatonic activity of drugs on rats/mice.
  14. Study of anxiolytic activity of drugs using rats/mice.
  15. Study of local anesthetics by different methods

Second Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

S Y B Pharm Sem IIIS Y B Pharm Sem IV
BP301T Pharmaceutical Organic Chemistry II TheoryBP401T Pharmaceutical Organic Chemistry III Theory
BP302T Physical Pharmaceutics I TheoryBP402T Medicinal Chemistry I Theory
BP303T Pharmaceutical Microbiology TheoBP403T Physical Pharmaceutics II Theory
BP304T Pharmaceutical Engineering TheoryBP404T Pharmacology I Theory
BP305P Pharmaceutical Organic Chemistry II PracticalBP405T Pharmacognosy I Theory
BP306P Physical Pharmaceutics I PracticalBP406P Medicinal Chemistry I Practical
BP307P Pharmaceutical Microbiology PracticalBP407P Physical Pharmaceutics II Practical
BP308P Pharmaceutical Engineering PracticalBP408P Pharmacology I Practical
BP409P Pharmacognosy I Practical

Suggested readings:

What is Actophotometer in pharmacology?

Actophotometer (Dolphin make) provided with a digital counter, photocell and a light source were used to measure locomotor activity (horizontal movement) of animals. Each animal was placed in Actophotometer for 5 minutes and basal activity score was recorded for all animals.
Reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4117029

What is the principle of Actophotometer?

It consists of six built in photo sensor and 4 digit digital counter to indicate the loco meter activity. It measures then spontaneous and indicated activity with digital totalize. It also incorporates electric shock of up to 100 volts for activating rats. The stimulus is variable from 0 to 100v & indicating on meter

What is the locomotor activity?

Locomotor activity is spontaneous movement of animals from one place to another.