Mossy fiber

Mossy fiber refers to the axons projected from the granule cells in the dentate gyrus and the pyramidal cells in the hippocampus. These fibers are a critical component of the trisynaptic circuit, which is a primary functional pathway in the hippocampus.

Anatomy

Mossy fibers are named for their appearance, as they exhibit a moss-like structure when observed under a microscope. They originate from the granule cells in the dentate gyrus and project to the CA3 region of the hippocampus. The fibers make excitatory synaptic connections with the dendrites of the pyramidal cells in the CA3 region.

Function

The primary function of mossy fibers is to transmit information from the granule cells to the pyramidal cells. This transmission is part of the trisynaptic circuit, which plays a crucial role in the processing and storage of memory and spatial navigation.

Clinical Significance

Alterations in mossy fiber pathways have been associated with several neurological disorders, including epilepsy and Alzheimer's disease. In epilepsy, mossy fiber sprouting, a phenomenon where the fibers form abnormal synaptic connections, has been observed. In Alzheimer's disease, a reduction in mossy fiber synapses has been reported.

Research

Research on mossy fibers has provided valuable insights into the functioning of the hippocampus and the pathophysiology of various neurological disorders. Studies have explored the role of these fibers in memory formation, spatial navigation, and the development of epilepsy and Alzheimer's disease.