Frerking M, Ohliger-Frerking P
Neurological Sciences Institute, Oregon Health and Science University, Beaverton, OR 97006, USA.
J Neurophysiol. 2006 Oct;96(4):2139-43. doi: 10.1152/jn.00243.2006. Epub 2006 Jun 14.
Presynaptic inhibition is a widespread mechanism for regulating transmitter release in the CNS. Presynaptic inhibitors act as a high-pass filter, but the functional consequence of this filtering during the synaptic processing of behaviorally relevant activity remains unknown. Here we use analytical approaches to examine the effects of presynaptic inhibition on synaptic output in response to activity patterns from CA3 pyramidal cells during the performance of a complex behavioral task. We calculate that presynaptic inhibition enhances the contrast between background activity and responses to environmental cues and that neuronal responses to location are subject to stronger contrast enhancement than neuronal responses to olfactory information. Our analysis suggests that presynaptic inhibition also enhances the importance of integrative inputs that respond to many behavioral cues during the task at the expense of specific inputs that respond to only a few of these cues.
突触前抑制是中枢神经系统中调节递质释放的一种广泛存在的机制。突触前抑制剂起到高通滤波器的作用，但在行为相关活动的突触处理过程中这种滤波的功能后果仍不清楚。在此，我们使用分析方法来研究突触前抑制对复杂行为任务执行过程中CA3锥体细胞活动模式所产生的突触输出的影响。我们计算得出，突触前抑制增强了背景活动与对环境线索反应之间的对比度，并且神经元对位置的反应比神经元对嗅觉信息的反应受到更强的对比度增强。我们的分析表明，突触前抑制还增强了在任务期间对许多行为线索做出反应的整合性输入的重要性，而牺牲了仅对其中少数线索做出反应的特异性输入。
