Characterization of spontaneous synaptic transmission in rat medial vestibular nucleus.
Spontaneous synaptic currents of medial vestibular nucleus (MVN) neurons were studied using whole cell recording in slices prepared from 13- to 17-day-old rats. The spontaneous inhibitory postsynaptic currents (sIPSCs) were significantly reduced by the GABAA antagonist bicuculline (20 microM), but were not affected by the glycine antagonist strychnine (1 microM). The frequency, amplitude, and decay time constant of sIPSCs were 4.3 +/- 0.9 Hz, 18.1 +/- 2.0 pA and 8.9 +/- 0.4 ms, respectively. The specific AMPA receptor antagonist GYKI-52466 (50 microM) completely blocked the non-NMDA-mediated spontaneous excitatory postsynaptic currents (sEPSCs), indicating that they are mediated by an AMPA-preferring receptor. The AMPA-mediated sEPSCs were characterized by low frequency (1.5 +/- 0.4 Hz), small amplitude (13.9 +/- 1.9 pA) and rapid decay kinetics (2.8 +/- 0.2 ms). The majority (15/21) displayed linear I-V relationships, suggesting the presence of GluR2-containing AMPA receptors.
Chun
Sang Woo
SW
Department of Oral Physiology, Wonkwang University College of Dentistry, Iksan 570-749, South Korea.
Choi
Jeong Hee
JH
Kim
Min Sun
MS
Park
Byung Rim
BR
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D001569:Benzodiazepines / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists; D018684:Glycine Agents / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000378:metabolism; D013331:Strychnine / Q000494:pharmacology; D009435:Synaptic Transmission / Q000502:physiology*; D014726:Vestibular Nuclei / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D058787:GABA-A Receptor Antagonists; D018684:Glycine Agents; D011810:Quinoxalines; D018091:Receptors, AMPA; C061950:GYKI 52466; D001569:Benzodiazepines; C056723:FG 9041; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; D013331:Strychnine; C104722:glutamate receptor ionotropic, AMPA 2; D001640:Bicuculline