Abstract
This study investigated the ethological and neurochemical impacts of Neem (Azadirachta indica) leaf extract in female Wistar rats, with focus on the social hierarchy, anxiety-like states, and the serotonergic system. Methodology: Sixteen rats were randomly allocated into two groups: a control (G1) and a Neem-treated group (G2). Behavioral alterations were assessed by Open Field, Resident-Intruder, Social Interaction, and Light-Dark tests. Following behavioral profiling, serum corticosterone and brain serotonin levels were quantified to identify physiological correlations. Results: Quantitative analysis of Resident-Intruder test revealed that Neem administration significantly increased aggressive behavior, evidenced by a marked reduction in attack latency and a great increase in total offense scores. In social contexts, treated rats exhibited profound social withdrawal, characterized by decreased social exploration and social preference scores. Light-Dark test results further indicated a lowered anxiety-like behavior, with G2 rats spending more time in the light arena and displaying increased displacement grooming. Biochemically, these shifts were associated with a significant increment in brain serotonin concentrations and a concurrent suppression in serum corticosterone. Conclusion: These findings indicate that Neem Leaf Extract works as a powerful modifier of brain chemistry, shifting behavior from social engagement to aggression. This transition appears to be driven by an increase in serotonin levels and decrease in hormonal stress pathways cortisone levels causing an anxiolytic effect. Ultimately, the extract overstimulates the brain’s systems, making rats physically angry, aggressive, and socially withdrawn.

Key words: Azadirachta indica, Aggression, Serotonin, Social Interaction, Anxiety, Corticosterone.