What part of the hippocampus is involved in nonspatial memory, and for how long?
The ventral hippocampus seems to serve a preferential role in the retrieval of information during STFP. No other subfield of the hippocampus showed a significant decrease or increase in Fos-IR associated with learning over the course of the consolidation period. We did observe an increase in Fos-IR in the VDG, but this increase could not be distinguished from a similar trend for increasing Fos expression observed in controls and therefore cannot be unambiguously associated with learning. Also, direct comparison of the increase in Fos-IR counts in the experimental groups during retrieval of STFP revealed a greater increase in the VSUB than the DSUB. These findings are consistent with a previous study showing an increase in c-fos activation in the ventral hippocampus but not the dorsal hippocampus during acquisition and retrieval 2 d after training in the STFP task (Countryman et al., 2005). These findings contrast with previous reports that the dorsal and ventral hippocampus are both ac
