Effects of fimbria-fornix lesions on avoidance tasks with temporal elements in rats

Abstract

Sidman schedule active avoidance, passive avoidance, and multiple avoidance (continuous alternation of active and passive avoidance) tasks were given to fimbria-fornix (FF)-lesioned ( n = 10) and control ( n = 10) rats to assess the effects of fimbria-fornix lesions on unsignaled avoidance learning with temporal cognition requirement. Active avoidance required subjects to make running responses, and passive avoidance required them to stop running and remain immobile on a running wheel. The tasks could be achieved purely by temporal cues, and no spatial elements were involved. Animals in the FF group performed the active, passive, and multiple avoidance tasks as well as control animals, showing no deficits by lesions in either the number of running responses nor the number of shocks received, although animals in the FF group displayed a greater negative transfer in passive avoidance when they received the active training before the passive training. The results indicate that fimbria-fornix lesions do not impair avoidance tasks when the tasks do not require spatial information, even if temporal information and/or inhibition are necessary to perform the tasks.