Functional double dissociation within the entorhinal cortex for visual scene-dependent choice behavior

How visual scene memory is processed differentially by the upstream structures of the hippocampus is largely unknown. We sought to dissociate functionally the lateral and medial subdivisions of the entorhinal cortex (LEC and MEC, respectively) in visual scene-dependent tasks by temporarily inactivating the LEC and MEC in the same rat. When the rat made spatial choices in a T-maze using visual scenes displayed on LCD screens, the inactivation of the MEC but not the LEC produced severe deficits in performance. However, when the task required the animal to push a jar or to dig in the sand in the jar using the same scene stimuli, the LEC but not the MEC became important. Our findings suggest that the entorhinal cortex is critical for scene-dependent mnemonic behavior, and the response modality may interact with a sensory modality to determine the involvement of the LEC and MEC in scene-based memory tasks.

Long–Term Recall Memory: Behavioral and Neuro–Developmental Changes in the First 2 Years of Life

Until not long ago, psychologists conceptually and methodologically linked the capacity for recall of the past to developments in language. With the advent of a nonverbal measure of recall, this association has been challenged. It now is apparent that the capacity for long–term recall emerges well before the verbal ability to describe past experiences. Long–term recall is newly (or recently) emergent late in the 1st year of life; over the 2nd year, it consolidates and becomes reliable. The course of age–related changes in mnemonic behavior is consistent with current understanding of developments in the neural substrate implicated in recall memory.