Effects of MT lesion on the initial and retention latencies tested in the inhibitory avoidance task. a. A typical example of histology illustrating the lesion site (arrow). Drawing of radiofrequency lesions of the MT sustained by rats in all experiments were composed in a series of coronal planes. The lighter areas indicate the maximum extent of all lesions, and the darker areas indicate the minimum damage sustained by any rat. b. Mean latency in seconds (± SE) to enter the dark compartment by MT Sham and MT lesion rats tested before, 30 s after (short retention test), and 24 h after (long retention test) footshock training.