Universidade do Porto

The work described here has the goal of providing mathematical models for important spatial information processing mechanisms in the brain. Two original models were developed targeting two core mechanisms: one dedicated to the phase precession effect and the other to the formation of hexagonal firing patterns of grid cells. Both mechanisms are embedded on the general problem of spatial information coding in the animal brain and, possibly in the human brain. The models were constructed in close relation with the known biophysical details of the brain areas being modeled. Phase precession is one of the most well-known examples within the temporal coding hypothesis. Here we present a biophysical spiking model for phase precession in hippocampal CA1 which focuses on the interaction between place cells and local inhibitory interneurons. The model's functional block is composed by a place cell (PC) connected with a local inhibitory cell (IC) which is modulated by the population theta rhythm. Both cells receive excitatory inputs from the entorhinal cortex (EC). These inputs are both theta modulated and space modulated. The dynamics of the two neuron types ar