Hypolocomotive and anxious behaviour in obese and type 2 diabetic rats: An experimental study

Objectives: The objectives of the study are to examine the comparative effects of obesity and diabetes on locomotor activity and anxiety-like behaviour in Charles Foster male rats. Materials and Methods: Eighteen male rats were divided into three groups: the Control group fed a normal pellet diet, the obese group fed a high-fat diet (HFD), and the diabetic group fed HFD followed by a single low dose of streptozotocin injection intraperitoneally (35 mg/kg bw). Open field test (OFT) and elevated plus maze (EPM) test were performed. The central latency time, ambulation, number of rearing, self-grooming, freezing time, and number of faecal boli released by each rat were the observed parameters in OFT. The number of entries into the open arm and total entries, duration and distance travelled in the open arm were the observed parameters in the EPM test. Data were analysed by one-way analysis of variance followed by Tukey’s post hoc test for multiple comparisons. Results: In OFT, there was a significant decrease in central latency time and ambulation in the obese and diabetic groups compared to the control group. In the obese and diabetic groups, there was a significant increase in freezing time compared to the control group. There was a significant increase in defecation in the obese and diabetic groups in comparison to the control group. In the EPM test, there was a significant decrease in the number of open arm entries, time spent in the open arm and distance travelled in the open arm in the obese and diabetic groups compared to the control group. Conclusion: In conclusion, the present study shows that reduced motor activity and hypolocomotive behaviour in OFT are comparable in both the diabetic and obese groups. In addition, both groups exhibit comparable exploratory behaviour and anxiety-like traits in EPM.