EFFECT OF FINE PARTICULATE MATTER EXPOSURE ON TRIGGERING DEPRESSIVE-LIKE RESPONSE AND TOTAL BODY WEIGHT IN C57BL/6J MICE

Objective: To study the effect of fine particulate matter exposure in instigating depressive-like response and total body weight changes in C57BL/6J mice. Study Design: Laboratory-based experimental study. Place and Duration of Study: Anatomy Department, Army Medical College, Rawalpindi, in collaboration with the Military Hospital, Rawalpindi and the National Institute of Health (NIH), Islamabad, from Jun to Sep 2020. Methodology: Thirty male and female C57BL/6 mice, 8 weeks of age, weighing 37 ± 2 gm were obtained from NIH, Islamabad. They were retained in separate cages in the animal house of NIH under standard laboratory conditions. The animals were divided into two groups, 15 mice in each group (8 males and 7 females) Group A was marked as control, received regular diet and water ad libitum. Group B (experimental group) received dynamic inhalation of 3 mg/m³ fine particles (soot) through air circulation for 6h/d for 12 weeks, in a plastic cabin measuring 2x2x2 feet fitted with two small fans for evenly distribution of PM. The initial and final weight of animals was recorded, and a tail suspension test was performed to assessdepression in form of immobility. Result: The experimental group after exposure to fine particulate matter showed decreased activity and behavioural deficits with p-value <0.001 and loss in total body weight as compared to the control group with a p-value <0.001. Conclusion: Fine particulate matter has a significant effect on behaviour and cognition. It also causes a decrease in the total body weight of animals due to stress and agitation.