The Mobility of AMPA-Type Glutamate Receptors as a Key Factor in the Expression and Maintenance of Synaptic Potentiation

The dynamics of the expression of post-tetanic potentiation of the focal response (the P spike) in the synaptic system consisting of Schaffer collaterals and field CA1 pyramidal neurons were studied in hippocampal slices from ICR mice. Potentiation was induced by high-frequency stimulation of Schaffer collaterals (1 sec, 100 Hz). At 10 sec, all slices in the group demonstrated an increase in the amplitude of the P spike in response to test stimuli. Slices with sharp increases in amplitude to maximal levels were seen, along with slices showing smooth increases in P-spike amplitude. Studies with the transport vesicle formation blocker brefeldin A assessed the relationship between the dependence of the phase of post-tetanic potentiation on intracellular transport. Brefeldin A was added to the perfusion solution before tetanic stimulation. This treatment of slices for 60 min had no effect on the magnitude of the basal P spike or the expression of post-tetanic potentiation, though it impaired the subsequent phase, i.e., maintenance of potentiation. A drop in P-spike amplitude was seen. The integrative activity of the system supporting the delivery of glutamate receptors to dendritic spines in the numbers and at the times required for rapid changes in and prolonged maintenance of the effectiveness of neurotransmission is discussed.

from Physiology via xlomafota13 on Inoreader http://ift.tt/2qscW4L
via IFTTT