Presynaptic Ca2+ Entry Is Unchanged during Hippocampal Mossy Fiber Long-Term Potentiation
Presynaptic Ca2+ Entry Is Unchanged during Hippocampal Mossy Fiber Long-Term Potentiation
复制标题
海马苔藓纤维长时程增强期间突触前 Ca2 进入未改变
DOI：
10.1523/jneurosci.22-24-10524.2002
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
T. Manabe
中科院分区：
文献类型：
--
作者：
H. Kamiya;Kazumasa Umeda;S. Ozawa;T. Manabe
海马苔藓纤维(Mf)-CA3突触呈现NMDA受体非依赖性长时程增强(LTP)，突触前机制导致递质释放持续增强。最近的研究已经确定了几个可能在MF-LTP中发挥重要作用的分子。其中包括Rab3A、RIM1α、红藻氨酸自身受体和超极化激活的阳离子通道(Ih)。然而，确切的细胞表达机制仍有待确定，因为一些研究注意到释放机械分子的基本作用，而另一些研究则表明影响钙离子进入突触前终末的离子亲电过程的调制。通过对海马片突触前钙离子的荧光记录，我们证明了在动作电位过程中，MF-LTP并不伴随突触前钙内流的增加。CA3神经元的全细胞记录显示，在高频刺激MFS后，微型EPSCs的平均频率持续增加，但平均幅度没有增加。这些数据表明，在MF-LTP过程中，导致递质释放增加的突触前表达机制涉及位于钙离子进入下游的突触前分子靶点的持续修饰。
The hippocampal mossy fiber (MF)–CA3 synapse exhibits NMDA receptor-independent long-term potentiation (LTP), which is expressed by presynaptic mechanisms leading to persistent enhancement of transmitter release. Recent studies have identified several molecules that may play an important role in MF-LTP. These include Rab3A, RIM1α, kainate autoreceptor, and hyperpolarization-activated cation channel (Ih). However, the precise cellular expression mechanism remains to be determined because some studies noticed essential roles of release machinery molecules, whereas others suggested modulation of the ionotropic processes affecting Ca2+ entry into the presynaptic terminals. Using fluorescence recordings of presynaptic Ca2+ in hippocampal slices, here we demonstrated that MF-LTP is not accompanied by an increase in presynaptic Ca2+ influx during an action potential. Whole-cell recordings from CA3 neurons revealed long-lasting increases in mean frequency, but not mean amplitude, of miniature EPSCs after the high-frequency stimulation of MFs. These data indicate that the presynaptic expression mechanisms responsible for enhanced transmitter release during MF-LTP involve persistent modification of presynaptic molecular targets residing downstream of Ca2+ entry.
DOI：
10.1016/s0021-9258(18)83165-9
发表时间：
1989-05
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
A. Minta;J. Kao;R. Tsien
通讯作者：
A. Minta;J. Kao;R. Tsien
影响因子：
56.9
作者：
ZALUTSKY, RA;NICOLL, RA
通讯作者：
NICOLL, RA