hippocampal mossy fiber pathway

Introduction

The 2nd fiber pathway of the trisynaptic circuit through the hippocampal formation. Fibers originate from granule cells in the dentate gyrus & synapse on proximal dendrites of pyramidal cells in the CA3 region of the hippocampus. Long-term potentiation (LTP) is observed in the mossy fiber pathway but may not be associative in nature.

Apparently, synapses of hippocampal mossy fibers are quite plastic. During torpor, synapses of mossy fibers & hippocampal pyramidal dendrites undergo regressive changes that fully & rapidly reverse during euthermia or activity. This rapid, reversible, & repeated regression of synaptic & dendritic components on CA3 neurons is associated with a reversible paired helical filament (PHF)-like phosphorylation of microtubule-associated protein tau at a similar time course.

More general terms

• mossy fiber

Additional terms

• cornus ammonis [CA]-3
• dentate gyrus
• long term potentiation (LTP)
• trisynaptic circuit