Gating of Ca2+-activated K+ channels controls fast inhibitory synaptic transmission at auditory outer hair cells

被引:200
作者
Oliver, D [1 ]
Klöcker, N [1 ]
Schuck, J [1 ]
Baukrowitz, T [1 ]
Ruppersberg, JP [1 ]
Fakler, B [1 ]
机构
[1] Univ Tubingen, Dept Physiol 2, D-72074 Tubingen, Germany
关键词
D O I
10.1016/S0896-6273(00)81197-6
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
Fast inhibitory synaptic transmission in the central nervous system is mediated by ionotropic GABA or glycine receptors. Auditory outer hair cells present a unique inhibitory synapse that uses a Ca2+-permeable excitatory acetylcholine receptor to activate a hyperpolarizing potassium current mediated by small conductance calcium-activated potassium (SK) channels. It is shown here that unitary inhibitory postsynaptic currents at this synapse are mediated by SK2 channels and occur rapidly, with rise and decay time constants of similar to 6 ms and similar to 30 ms, respectively. This time course is determined by the Ca2+ gating of SK channels rather than by the changes in intracellular Ca2+. The results demonstrate fast coupling between an excitatory ionotropic neurotransmitter receptor and an inhibitory ion channel and imply rapid, localized changes in subsynaptic calcium levels.
引用
收藏
页码:595 / 601
页数:7
相关论文
共 32 条
[11]   Calmodulin mediates calcium-dependent activation of the intermediate conductance KCa channel, IKCa1 [J].
Fanger, CM ;
Ghanshani, S ;
Logsdon, NJ ;
Rauer, H ;
Kalman, K ;
Zhou, JM ;
Beckingham, K ;
Chandy, KG ;
Cahalan, MD ;
Aiyar, J .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1999, 274 (09) :5746-5754
[12]  
FUCHS PA, 1992, J NEUROSCI, V12, P800
[13]  
Guinan Jr J. J., 1996, PHYSL OLIVOCOCHLEAR, P435
[14]   Gating properties of single SK channels in hippocampal CA1 pyramidal neurons [J].
Hirschberg, B ;
Maylie, J ;
Adelman, JP ;
Marrion, NV .
BIOPHYSICAL JOURNAL, 1999, 77 (04) :1905-1913
[15]   IONIC CURRENTS OF OUTER HAIR-CELLS ISOLATED FROM THE GUINEA-PIG COCHLEA [J].
HOUSLEY, GD ;
ASHMORE, JF .
JOURNAL OF PHYSIOLOGY-LONDON, 1992, 448 :73-98
[16]   DIRECT MEASUREMENT OF THE ACTION OF ACETYLCHOLINE ON ISOLATED OUTER HAIR-CELLS OF THE GUINEA-PIG COCHLEA [J].
HOUSLEY, GD ;
ASHMORE, JF .
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, 1991, 244 (1310) :161-167
[17]   Corelease of two fast neurotransmitters at a central synapse [J].
Jonas, P ;
Bischofberger, J ;
Sandkühler, J .
SCIENCE, 1998, 281 (5375) :419-424
[18]   The impact of receptor desensitization on fast synaptic transmission [J].
Jones, MV ;
Westbrook, GL .
TRENDS IN NEUROSCIENCES, 1996, 19 (03) :96-101
[19]   Domains responsible for constitutive and Ca2+-dependent interactions between calmodulin and small conductance Ca2+ activated potassium channels [J].
Keen, JE ;
Khawaled, R ;
Farrens, DL ;
Neelands, T ;
Rivard, A ;
Bond, CT ;
Janowsky, A ;
Fakler, B ;
Adelman, JP ;
Maylie, J .
JOURNAL OF NEUROSCIENCE, 1999, 19 (20) :8830-8838
[20]   Modeling buffered Ca2+ diffusion near the membrane: Implications for secretion in neuroendocrine cells [J].
Klingauf, J ;
Neher, E .
BIOPHYSICAL JOURNAL, 1997, 72 (02) :674-690