Summary: A MODEL OF SPATIAL MAP FORMATION
IN THE HIPPOCAMPUS OF THE RAT
Kenneth I. Blum* and L.F. Abbott
Center for Complex Systems
Waltham, MA 02254
Published in Neural Comp. 8:85-93 (1996).
Using experimental facts about long-term potentiation (LTP) and hippocampal place
cells, we model how a spatial map of the environment can be created in the rat hippocam-
pus. Sequential firing of place cells during exploration induces, in the model, a pattern
of LTP between place cells that shifts the location coded by their ensemble activity away
from the actual location of the animal. These shifts provide a navigational map that, in a
simulation of the Morris maze, can guide the animal toward its goal. The model demon-
strates how behaviorally generated modifications of synaptic strengths can be read out to
affect subsequent behavior. Our results also suggest a way that navigational maps can be
constructed from experimental recordings of hippocampal place cells.
*Current address: Dept. of Brain and Cognitive Sciences, MIT E25-236, 45 Carlton St.,
Cambridge, MA 02139.
Blockade of long term potentiation (LTP) and hippocampal lesions drastically impair