Place navigation in rats with unilateral tetrodotoxin inactivation of the dorsal hippocampus: place but not procedural learning can be lateralized to one hippocampus

摘要: Lateralization of the Morris water maze task was examined by injecting 5 ng tetrodotoxin (TTX) into one dorsal hippocampus (HPC) chronically cannulated rats (n = 20). The task, acquired (A) during unilateral HPC block, retrieved (R) TTX blockade ipsi- (I) or contralateral (C) HPC. Escape latencies (in seconds) at 3 levels acquisition and in first 4-trial block I C retrieval suggest lateralization absent after (A 49, 40, 44), partial training to an efficient search strategy 6, 9, 14), complete overtraining goal-directed escape 4, 12), as further indicated comparisons A vs. R behavior probe trials. analyses also indicate that (a) contributes but is unnecessary for procedural engram, (b) overtrained learning with intact brain similar, (c) there no left-right hemispheric specialization place learning.