Wistar Experiment Report

2. Materials and methods
2.1. Animals
Experiments were carried out in adult male Wistar rats (200-225 g; 2-2.5 months old), obtained from Central Animal Research Facility, NIMHANS, Bengaluru. Adult rats were group-housed (3 per cage) in a climate-controlled vivarium with a 12:12 h dark/light cycle. All animals had free access to food and drinking water except during the stress procedure or behavioral evaluation. All the experiments were performed during the light phase between 10:00 h and-14:00 h.
All experiments were approved by the Institutional Animal Ethical Committee and performed according to the guidelines of the Committee for the Purpose of Control and Supervision of Experiments on Animals, Government of India.
2.2. Experimental groups
Animals were randomly assigned to normal controls (NC - naïve animals), sham controls [SC (IBO) -
A 30 gauge stylet was inserted to maintain the patency of the cannula. Following surgery, the rats were allowed 10 days to recover and then subjected to temporary inactivation of BLA prior to chronic immobilization stress. The lidocaine (20 µg/ml) was freshly prepared in isotonic saline and injected using 30 gauge infusion needle fitted in guide cannula by removing the stylet. The tip of the infusion needle protruded 1 mm below the guide cannula to reach the BLA. Lidocaine (2µl/side) was infused bilaterally over a period of 3 minutes (Parent and McGaugh, 1994; Almaguer-Melian et al., 2003; Ahn and Phillips, 2003). The needle was retained in place for an additional 2 min for diffusion. These infusions were carried out every day for 10 days, 30 min before subjecting them to CIS. The vehicle controls were infused with isotonic saline before stress paradigm. The sham controls were subjected to implantation of cannula, but lidocaine was not