Development of the hippocampal cognitive map in preweanling rats.
Orienting in large-scale space depends on the interaction of environmental experience and preconfigured, possibly innate, constructs. Place, head-direction, and grid cells in the hippocampal formation provide allocentric representations of space. Here we show how these cognitive representations emerge and develop as rat pups first begin to explore their environment. Directional, locational, and rhythmic organization of firing are present during initial exploration, including adultlike directional firing. The stability and precision of place cell firing continue to develop throughout juvenility. Stable grid cell firing appears later but matures rapidly to adult levels. Our results demonstrate the presence of three neuronal representations of space before extensive experience and show how they develop with age.
Wills
Tom J
TJ
Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK. t.wills@ucl.ac.uk
Cacucci
Francesca
F
Burgess
Neil
N
O'Keefe
John
J
D000200:Action Potentials; D000375:Aging; D000818:Animals; D000833:Animals, Suckling; D001931:Brain Mapping; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D003071:Cognition; D004567:Electrodes, Implanted; D018728:Entorhinal Cortex / Q000166:cytology / Q000502:physiology*; D005106:Exploratory Behavior; D008297:Male; D009474:Neurons / Q000502:physiology*; D009949:Orientation; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D013028:Space Perception; D013037:Spatial Behavior; D013826:Theta Rhythm