Dentate Gyrus

The dentate gyrus is part of the hippocampal formation. It is thought to contribute to the formation of new memories, as well as possessing other functional roles. It is notable as being one of a select few brain structures currently known to have high rates of neurogenesis in adult rats (other sites include the olfactory bulb and cerebellum).

The dentate gyrus cells receive excitatory input from the entorhinal cortex, in the medial temporal lobe, through the perforant path into the molecular layer. This activates pyramidal cells among the CA4 and CA3 pyramidal neurons (CA stands for cornu ammonis), which are components of Ammon's horn within the hippocampus. Tracts exit CA3 neurons via the Schaffer collaterals and activate CA1 pyramidal cells, allowing the dentate gyrus to be in a position to control the flow of information within the hippocampus.