Auditory cortical function Insights from current approaches
Auditory cortical function Insights from current approaches
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听觉皮层功能 对当前方法的见解
DOI：
10.1121/1.4729579
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
and Lomber SG
中科院分区：
文献类型：
--
作者：
Schreiner CE;Kanold PO;Ojima H;Shamma SA;and Lomber SG
最近，使用突触电导的全细胞记录，我们发现，如果声刺激与基底核胆碱能神经调节系统的激活配对，则诱导听觉皮层兴奋性突触的持久的正性和负性变化（Froemke等人，2007年）。在感受野内的次优刺激与乙酰胆碱的释放配对仅几分钟，增强了对配对频率的兴奋性反应（图1B），但降低了神经元前BF的兴奋性活动。此外，成对频率下神经元的抑制电导暂时降低（图1C），但在几十分钟后恢复，与神经元的新BF匹配（Froemke等人，我们还发现，基底核激活的可塑性可以扩展到形状强度调谐。当我们检查声音水平强度的突触调谐曲线时，我们发现音调诱发的兴奋随着声音水平的增大而单调增加。然而，在将安静的低强度音调与基底核刺激配对后，对最初较弱的柔和音调的反应变得较强，而对较大音调的反应则受到抑制（Carcea等人，2012年）。这些突触修饰在整个感受野中被精确地协调，保留了平均兴奋，同时降低了总体方差，这意味着皮层突触感受野的每个参数（频率和强度）都可以独立地被修饰。
Recently, using whole-cell recordings of synaptic conductances, we found that long-lasting positive and negative changes to auditory cortical excitatory synapses were induced, if acoustic stimuli were paired with activation of the nucleus basalis cholinergic neuromodulatory system (Froemke et al., 2007). Pairing of a sub-optimal stimulus inside the receptive field with release of acetylcholine for only a few minutes enhanced the excitatory response to the paired frequency (Fig. 1B), but decreased the excitatory activity at the former BF of the neurons. In addition, the inhibitory conductance of the neurons at the paired frequency was reduced temporarily (Fig. 1C), but recovered after several tens of minutes matching the new BF of the neuron (Froemke et al., 2007).We also found that nucleus basalis-enabled plasticity could be extended to shape intensity tuning. When synaptic tuning curves for sound level intensity were examined, we found that tone-evoked excitation monotonically increased as sound level grew louder. However, after pairing a quiet, low-intensity tone with nucleus basalis stimulation, responses to soft tones that were initially weak became stronger, and responses to louder tones were depressed (Carcea et al., 2012). These synaptic modifications were precisely orchestrated across entire receptive fields, conserving mean excitation while reducing overall variance, which implied that each parameter of cortical synaptic receptive fields (frequency and intensity) could be modified independently of the other