  The proposed analysis of the currently available experimental results
concerning the neural cell activity in the brain area known as hippocampus
suggests a particular mechanism of spatial information and memory processing.
Below it is argued that the spatial information available through the analysis
of the hippocampal cell activity is predominantly of topological nature. It is
pointed out that a direct topological analysis can produce a topological
invariant based classification of the cell activity patterns and a complete
topological description of animal's current environment. It also provides a
full first order logical system for local topological reasoning about spatial
structure and animal's navigational strategies.
