4 Study of Stress, Anxiety and Depression in Type 2 Diabetic Model of Zebrafish (Danio rerio)

Ikhlef Hassina1*,  Aouar-Sadli Malika2, Korichi Yamina3, Medjdoub-Bensaad Ferroudja4

Shovit Ranjan1* and Praveen Kumar Sharma2
1Department of Zoology, Miranda House, University of Delhi, Delhi 110007, India.
2Department of Life Sciences, Central University of Jharkhand, Brambe, Ranchi, Jharkhand 835205, India.
Corresponding author email id: shovitranjan@gmail.com; shovit.ranjan@mirandahouse.ac.in

ABSTRACT
Type 2 Diabetes (T2D), which causes hyperglycemia, affects the central nervous system, leading to certain neurobehavioral disorders. These days, zebrafish (Danio rerio) has emerged as a promising model organism for experimental studies of neurobehavioral disorders like stress, anxiety and depression. The aim of this study was to investigate the effects of high sucrose induced hyperglycemia or T2D on stress, anxiety as well as depression like behavior of zebrafish. Hyperglycemia was induced in adult zebrafish by immersion in 83.25 mM sucrose solution for 14 days after performing the study for survival in sucrose solutions.  The animals were divided into 2 groups in replicates: control and sucrose-treated hyperglycemic groups. Afterwards, the behavioral performance was evaluated in both the groups using novel tank diving test and light-dark box test.High-sucrose induced hyperglycemic group produced robust anxiogenic effects like increased latency, reduced exploration in the top of the tank, increased erratic movements and freezing behavior in the novel tank diving test and scototaxis like behavior in the light-dark box test. Overall, our results confirm that an unfamiliar environment of high-sucrose induced hyperglycemia in the zebrafishes can evoke relatively simple, yet robust stress, anxiety and depression-like behavioral responses.

Keywords
Type 2 Diabetes, Hyperglycemia, Zebrafish, Stress, Anxiety, Depression, Novel tank test, Light-dark box test.