Distinct ensemble codes in hippocampal areas CA3 and CA1.
The hippocampus has differentiated into an extensively connected recurrent stage (CA3) followed by a feed-forward stage (CA1). We examined the function of this structural differentiation by determining how cell ensembles in rat CA3 and CA1 generate representations of rooms with common spatial elements. In CA3, distinct subsets of pyramidal cells were activated in each room, regardless of the similarity of the testing enclosure. In CA1, the activated populations overlapped, and the overlap increased in similar enclosures. After exposure to a novel room, ensemble activity developed slower in CA3 than CA1, suggesting that the representations emerged independently.
Centre for the Biology of Memory, Medical-Technical Research Centre, Norwegian University of Science and Technology, 7489 Trondheim, Norway.
Stefan
S
Leutgeb
Jill K
JK
Leutgeb
Alessandro
A
Treves
May-Britt
MB
Moser
Edvard I
EI
Moser
D000200:Action Potentials; D000818:Animals; D001931:Brain Mapping; D003463:Cues; D004567:Electrodes, Implanted; D018728:Entorhinal Cortex / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D008297:Male; D008568:Memory; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D013028:Space Perception