Enhancement of postsynaptic responsiveness during long-term potentiation of mossy fiber synapses in guinea pig hippocampus.
The primary site responsible for the long-lasting enhancement of synaptic transmission during long-term potentiation (LTP) was examined by quantal analysis of excitatory postsynaptic potentials in thin sections of the guinea pig hippocampus. With induction of LTP in mossy fiber synapses, estimated values of quantal amplitude (q) and Pascal parameters p and r were increased significantly. No increases in quantal content (m) were detected. The magnitude of increases in q was almost equal to that of LTP. These results indicate that LTP in mossy fiber synapses results from increases in responsiveness of postsynaptic neurons.
Yamamoto
C
C
Department of Physiology, Faculty of Medicine, Kanazawa University, Japan.
Sawada
S
S
Kamiya
H
H
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D004558:Electric Stimulation; D005071:Evoked Potentials; D006168:Guinea Pigs; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D009412:Nerve Fibers / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology; D013569:Synapses / Q000502:physiology*