The dentate gyrus receives excitatory projections from neurons in layer II of the entorhinal cortex as well as input from surrounding neuroglia. The unmyelinated granule cell axons of the mossy fiber pathway express both GABA receptors and glutamate receptors along their membranes that allow them to be modulated by both excitatory and inhibitory input from nearby glial cells. Axons from the entorhinal cortex synapse primarily on the dendritic spines of outer layer dentate granule cells. The entorhinal cortex passes sensory information from neocortical structures to the hippocampal formation. The pathway allows sensory information to reach the hippocampus for encoding.
