Turning preferences in the corner turning test and the status of proinflammatory cytokines in the right-left brain hemispheres in the lipopolysaccharide-induced neuroinflammation model

Abstract

Aims: Neuroinflammation is described as an inflammatory response within the nervous system. The study aimed to investigate the behavior of rats in the corner turning test and the distribution of proinflammatory cytokines between the right/left hemispheres in the neuroinflammation model induced by lipopolysaccharide. Furthermore, locomotor activity, anxiety-like behaviors, and stress-related harderian gland secretion were also analyzed. Methods: 12 adults male Wistar albino rats were divided into control (n=6) and neuroinflammation animals (n=6). The neuroinflammation group received a single dose of 2 mg/kg intraperitoneally LPS, and 1 ml/kg physiological saline was administered to the control group. Six hours after LPS administration, open field test was performed for 5 minutes. The corner rotation test protocol was performed 6 and 24 hours after LPS administration. Subjects were sacrificed 24 hours after LPS administration. TNF-a and IL-1beta were analyzed in the prefrontal cortex, striatum, and serum. All procedures were conducted with the approval of the Balıkesir University Experimental Animals Ethics Committee (Date: 22.11.2023, Decision No: 2023/10- 5). Results were analyzed using the students’ T test. Results: In the open field test, locomotor activity decreased (p<0.0001), while anxiety-like behaviors increased (p<0.05-p<0.0001). Harderian gland secretion significantly increased by 4-5 points in the neuroinflammation group (p<0.0001). No difference was observed between the control and LPS groups in the corner-turning test (p>0.05). TNF-alpha and IL-1beta significantly increased compared to the control group (p<0.01-p<0.0001). There was no difference in proinflammatory cytokines between the right hemispheres (p>0.01). Conclusion: In the neuroinflammation group, anxiety-like behaviors and proinflammatory cytokines increased. Stress-related spotting around the eyes and nose increased. According to the corner-turning test, no significant difference was observed. More studies are needed in neuroinflammation models with the corner-turning test, which examines damage to the hemispheres in neurological experiments.