Developmental changes in the BDNF-induced modulation of inhibitory synaptic transmission in the Kolliker-Fuse nucleus of rat
Developmental changes in the BDNF-induced modulation of inhibitory synaptic transmission in the Kolliker-Fuse nucleus of rat
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DOI：
10.1111/j.1460-9568.2007.05960.x
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发表时间：
2007-12-01
影响因子：
3.4
通讯作者：
Dutschmann, Mathias
中科院分区：
文献类型：
--
作者：
Kron, Miriam;Zhang, Weiqi;Dutschmann, Mathias
Kolliker-Fuse核(KF)是脑桥呼吸群的一部分，参与呼吸时程的控制，接受来自不同脑区的兴奋性和抑制性传入。有证据表明，神经营养因子脑源性神经营养因子(BDNF)对KF的兴奋性输入的调节发生了发育变化。在本研究中，我们研究了BDNF是否在KF抑制性突触传递中发挥发育作用。在脑桥脑片上记录的KF神经元的抑制性突触后电流(IPSCs)显示了一般的发育变化。自发和诱发性IPSCs(sIPSCs，eIPSCs)的记录显示，出生时IPSCs中的GABA能成分占主导地位，而在发育后期甘氨酸能神经递质显著增加。在各个发育阶段，沐浴应用BDNF显著降低了sIPSC的频率，而BDNF对eIPSCs的调节则表现出发育差异。只有出生后10d以下的大鼠神经元中的eIPSCs平均波幅在BDNF作用下均匀而显著降低。在出生后的后期，这种反应模式变得不同，eIPSC波幅既有增大又有降低。酪氨酸激酶B受体阻断剂K252a可逆转BDNF对eIPSCs和sIPSCs的作用。我们的结论是，抑制性神经传递的发育变化，包括BDNF介导的eIPSCs的调节，与出生后KF的成熟有关。BDNF介导的KF内IPSCs调控的变化可能对突触可塑性的发育变化和呼吸模式对传入输入的适应具有重要意义。
The Kolliker-Fuse nucleus (KF), part of the pontine respiratory group, is involved in the control of respiratory phase duration, and receives both excitatory and inhibitory afferent input from various other brain regions. There is evidence for developmental changes in the modulation of excitatory inputs to the KF by the neurotrophin brain-derived neurotrophic factor (BDNF). In the present study we investigated if BDNF exerts developmental effects on inhibitory synaptic transmission in the KF. Recordings of inhibitory postsynaptic currents (IPSCs) in KF neurons in a pontine slice preparation revealed general developmental changes. Recording of spontaneous and evoked IPSCs (sIPSCs, eIPSCS) revealed that neonatally the gamma-aminobutyric acid (GABA)ergic fraction of IPSCs was predominant, while in later developmental stages glycinergic neurotransmission significantly increased. Bath-application of BDNF significantly reduced sIPSC frequency in all developmental stages, while BDNF-mediated modulation on eIPSCs showed developmental differences. The eIPSCs mean amplitude was uniformly and significantly reduced following BDNF application only in neurons from rats younger than postnatal day 10. At later postnatal stages the response pattern became heterogeneous, and both augmentations and reductions of eIPSC amplitudes occurred. All BDNF effects on eIPSCs and sIPSCs were reversed with the tyrosine kinase receptor-B inhibitor K252a. We conclude that developmental changes in inhibitory neurotransmission, including the BDNF-mediated modulation of eIPSCs, relate to the postnatal maturation of the KF. The changes in BDNF-mediated modulation of IPSCs in the KF may have strong implications for developmental changes in synaptic plasticity and the adaptation of the breathing pattern to afferent inputs.