Effects of blockers of voltage-operated potassium channels on an NMDA component of excitatory synaptic transmission in theCA1 subfield of the rat hippocampus |
| |
Authors: | M V Kopanitsa N A Lozovaya Ya A Boychuk O A Krishtal |
| |
Institution: | (1) Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine;(2) International Center for Molecular Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine |
| |
Abstract: | The effects of voltage-operated potassium channel blockers on evoked excitatory synaptic transmission were studied in theCA1 subfield of rat hippocampal slices. Incubation with 50 μM 4-aminopyridine (n=27), 300 nM α-dendrotoxin (n=3), or 5 to 25 mM tetraethylammonium (n=7) resulted in an enhancement of the peak amplitude
of excitatory postsynaptic currents (EPSC) and significant prolongation of their decay at strong stimuli, due to an increased
contribution of NMDA receptors into EPSC. In five experiments, the presence of an AMPA receptor antagonist, 4-aminopyridine,
led to the appearance of NMDA receptor-mediated field excitatory postsynaptic potentials (fEPSP). It is suggested that various
modulations increasing presynaptic Ca2+ entry and, consequently, glutamate release may increase an NMDA component of synaptic transmission via excitation of polysynaptic
excitatory pathways and/or due to glutamate spillover to distant extrasynaptic NMDA receptors. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|