Fig.1.

A simplified hippocampal circuitry illustrating trisynaptic and monosynaptic circuits. The basic circuitry of the hippocampus is commonly termed the trisynaptic circuit. Layer II of the entorhinal cortex provides input to the granule cells of the dentate gyrus via the medial (light blue) and lateral (purple) perforant paths. The dentate granule cells project to pyramidal cells of the CA3 via the mossy fibre pathway (green). CA3 pyramidal neurons project to the CA1 via schaffer collaterals (pink). The CA1 pyramidal cells project to both the subiculum and to layers V and VI of the entorhinal cortex. Abbreviations: Cornu Ammonis (CA); Dentate Gyrus (DG); Entorhinal Cortex (EC); Lateral Perforant Path (LPP); Medial Perforant Path (LPP); Mossy Fibres (MF); Schaffer Collaterals (SC); Subiculum (S).