ACC at the following coordinates relative to bregma (injection 1: AP, +0.2 mm; ML: ±0.5 mm; DV: −2.2 mm; injection 2: AP, +1.2 mm; ML: ±0.5 mm; DV: −2.2 mm). Coordinates were chosen based on a previous recording study targeting the same area (11) and in consultation with the authors of two previous ibotenic acid lesion studies that also targeted this brain region (10, 39). For each injection site, a beveled 33-ga, 5-µL Neuros Syringe (Hamilton) was lowered slowly over the course of 5 min to its final depth. Care was taken to ensure that the bevel of the needle was positioned away from the midline of the brain (10, 39). Rats were unilaterally infused with either 0.2 µL of 0.6 M ibotenic acid in saline or 0.2 µL of 0.9% saline per site over the course of 3 min (approximately 125 nL/min). Needles were left in place for 5 min before being slowly removed over the course of an additional 5 min in order to minimize the risk of tissue damage and backflow. Holes were loosely filled with sterile bonewax prior to beginning electrode implantation.
