Figure 1.

Schematic representation of the structural organization of the rat hippocampus. It is known that the hippocampus is connected to the entorhinal cortex through different anatomical circuitries that have been well described. Particularly, the perforant pathway projects from the DG and the CA3 to the CA1 (green and blue arrows). One of the characteristics of this circuitry is its directionality between the different neuronal layers. The DG, CA3 and the apical layers of CA1 (orange arrows) project mainly via the superficial layers of the entorhinal cortex (II and III). On the other hand, many pieces of evidence have reported that the hippocampus is highly vulnerable to cell loss via seizure activity, particularly in the CA1 and CA3 subfields (red marks). The dispersion of dentate granular cells (yellow arrows) and intense axonal sprouting (asterisks) are common in epileptogenesis process. These structural changes affects the organization and function of hippocampal circuitry and contribute to the establishment of the TLE.