Transecting the dorsal fornix results in novelty detection but not temporal ordering deficits in rats

It has been shown that CA1 subserves temporal ordering processes in the hippocampus. It has also recently been shown that transecting the subcortical outputs of dorsal CA1 via the dorsal fornix results in retrieval deficits similar to those seen after lesions to CA1. The present experiment was designed to evaluate the effects of disrupting CA1 subcortical outputs for the temporal processing of visual objects and for a visual object novelty detection paradigm. The results of the present study suggest that CA1 subcortical efferents are not critically involved in temporal processing of visual objects, but are critically involved in visual object novelty detection. The data also suggest that temporal processing and novelty detection may potentially be subserved by independent mechanisms in CA1.