Differential modulation of lateral septal vasopressin receptor blockade inspatial learning, social recognition, and anxiety-related behaviors in rats

The role of lateral septal vasopressin (VP) in the modulation of spatial me mory, social memory, and anxiety-related behavior was studied in adult, mal e Wistar rats. Animals were equipped with osmotic minipumps delivering the VP-antagonist d(CH2)5-D-Tyr(Et)VAVP (1 ng/0.5 mu l per h) bilaterally into the lateral septum (LS). Subsequently, all rats were subjected to four beha vioral tests. First, animals were tested in a spatial learning paradigm (Mo rris water maze; 12 trials), followed by the social recognition test. A pos sible role for VP in anxiety-related behavior was then studied in the shock -probe burying test and the elevated plus-maze, respectively. The results s howed that VP receptor antagonism impaired social recognition and reduced o pen-arm activity in the plus-maze, while it had no effect on spatial learni ng (Morris maze) and shock-probe burying behavior. The results indicate a s trong task-dependent specificity of lateral septal VP functioning. (C) 1999 Elsevier Science B.V. All rights reserved.