The ensemble activity of hippocampal neurons carries information about the location of an animal in its environment (see ‘A code for space‘). For example, one may find that cell 1 is only active when a rat is in location A; and cell 2 is only active when the rat is in location B. Conversely, if…

Structures in the medial temporal lobe, including the hippocampus and entorhinal cortex, are associated with memory function. In humans and animal models, damage of the hippocampus leads to deficits in the ability to remember new information (anterograde amnesia) and impairments in recall of old memories (retrograde amnesia). In rodents, the hippocampus is often studied in…