Effects of baclofen on transient neurons in the mudpuppy retina: electrogenic and network actions.
Effects of baclofen on transient neurons in the mudpuppy retina: electrogenic and network actions.
复制标题
巴氯芬对泥巴犬视网膜瞬时神经元的影响：生电和网络作用。
DOI：
10.1152/jn.1989.61.2.382
复制
发表时间：
1989
影响因子：
2.5
通讯作者：
Slaughter,MM
中科院分区：
文献类型：
--
作者：
Bai,SH;Slaughter,MM
1.巴氯芬增加了无长突细胞和神经节细胞的瞬时光反应，尽管它是一种经典的抑制性递质，可以抑制这些细胞的过度增殖和分流。2.这种效应似乎发生在内层视网膜的水平，似乎不是由于双极细胞的额外输入。3.在某些瞬态细胞中，巴氯芬增加光反应的总振幅，但不改变光诱发EPSP的峰电位。在这些细胞中，由超极化引起的兴奋性突触后电位（EPSP）驱动力的增加可以解释Bacterium诱导的增强。4.然而，在其他细胞中，巴氯芬应用后的光响应的峰值更大，这不能通过驱动力的变化来解释。巴氯芬的这种作用可以通过γ-氨基丁酸（GABA）和甘氨酸的阻断剂来模拟，这表明在这些细胞中巴氯芬的增强部分是由于网络效应导致持续抑制的消除。5.因此，产生突触反应增强的抑制性递质的矛盾效应似乎是由于至少两种机制。6.结果表明，某些瞬时细胞受到明显的紧张性抑制，以推拉式机制限制其反应幅度，而另一些细胞则不受这种抑制性控制。
1. Baclofen increases transient light responses of amacrine and ganglion cells despite acting as a classical inhibitory transmitter to both hyperpolarize and shunt these cells. 2. This effect seems to occur at the level of the inner retina and appears not to be due to an additional input from bipolar cells. 3. In some transient cells baclofen increases the total amplitude of the light response but does not change the peak potential of the light evoked EPSP. In these cells, the baclofen-induced enhancement can be accounted for by an increase in driving force of the excitatory postsynaptic potential (EPSP) resulting from the hyperpolarization. 4. However, in other cells the peak of the light response after baclofen application is greater, which cannot be accounted for by a change in driving force. This effect of baclofen can be mimicked by a blockers of gamma-aminobutyric acid (GABA) and glycine, suggesting that in these cells baclofen's enhancement is due in part to network effects resulting in a removal of sustained inhibition. 5. Therefore, the paradoxical effect of an inhibitory transmitter producing an enhancement of synaptic responses seems due to at least two mechanisms. 6. The results indicate that some transient cells receive significant tonic inhibition which limits their response amplitude in a push-pull type mechanism, but other cells are not under this inhibitory control process.