Phase-locked responses to pure tones in the auditory thalamus.
Phase-locked responses to pure tones in the auditory thalamus.
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DOI：
10.1152/jn.00697.2007
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发表时间：
2007-10
影响因子：
2.5
通讯作者：
M. N. Wallace;L. Anderson;A. Palmer
中科院分区：
文献类型：
--
作者：
M. N. Wallace;L. Anderson;A. Palmer
通过锁定到正弦波的特定相位（锁相）的尖峰对低频音调进行准确的时间编码，发生在大脑中处于不同处理水平的特定神经元组中。锁相反应先前已经在豚鼠的下丘和新皮层中进行了研究，现在我们描述了听觉丘脑中的反应。记录了241个单单元，其中32个（13%）显示锁相响应。锁相反应的单元主要位于内侧膝状体（MGB）的腹侧部（82%）和内侧部（18%），但在背侧和壳部未发现。锁相上限频率在不同单元（60- 1100 Hz）和不同解剖分区之间变化很大。腹侧的上限为520 Hz，内侧的上限为1100 Hz。从相位图计算的稳态延迟范围也有所不同：腹侧分割，8.6-14 ms（平均11.1 ms, SD 1.56）；内侧分裂，7.5-11 ms（平均9.3 ms; SD 1.5）。综上所述，这些测量结果与内侧分裂直接从脑干接收锁相输入相一致，而没有在下丘进行强制性中继。MGB的腹侧和内侧分裂的细胞都显示出与豚鼠咕噜声的基本频率相锁的反应，可能与分析通信呼叫有关。
Accurate temporal coding of low-frequency tones by spikes that are locked to a particular phase of the sine wave (phase-locking), occurs among certain groups of neurons at various processing levels in the brain. Phase-locked responses have previously been studied in the inferior colliculus and neocortex of the guinea pig and we now describe the responses in the auditory thalamus. Recordings were made from 241 single units, 32 (13%) of which showed phase-locked responses. Units with phase-locked responses were mainly (82%) located in the ventral division of the medial geniculate body (MGB), and also the medial division (18%), but were not found in the dorsal or shell divisions. The upper limiting frequency of phase-locking varied greatly between units (60-1,100 Hz) and between anatomical divisions. The upper limit in the ventral division was 520 Hz and in the medial was 1,100 Hz. The range of steady-state delays calculated from phase plots also varied: ventral division, 8.6-14 ms (mean 11.1 ms; SD 1.56); medial division, 7.5-11 ms (mean 9.3 ms; SD 1.5). Taken together, these measurements are consistent with the medial division receiving a phase-locked input directly from the brain stem, without an obligatory relay in the inferior colliculus. Cells in both the ventral and medial divisions of the MGB showed a response that phase-locked to the fundamental frequency of a guinea pig purr and may be involved in analyzing communication calls.