Neurons sensitive to interaural phase disparity in gerbil superior olive: diverse monaural and temporal response properties.
Neurons sensitive to interaural phase disparity in gerbil superior olive: diverse monaural and temporal response properties.
复制标题
DOI：
10.1152/jn.1995.73.4.1668
复制
发表时间：
1995-04
影响因子：
2.5
通讯作者：
M. W. Spitzer;M. Semple
中科院分区：
文献类型：
--
作者：
M. W. Spitzer;M. Semple
1. 我们通过记录麻醉沙鼠（Meriones unguiculatus）的上橄榄复合体（SOC）中的单个单元反应，评估了双耳相互作用的机制，该机制是检测耳间相位差（IPD）的基础。双耳反应是从 58 个 IPD 敏感的单个单元获得的，其中 44 个是组织学局部的。还获得了 58 个 IPD 敏感单元中 52 个的单耳反应。此外，还记录了侧向 SOC 中 16 个单位（最佳频率 < 2.4 kHz）的响应，这些单位被同侧刺激激发并被对侧刺激 (EI) 抑制，其中没有一个对 IPD 敏感。我们的结果与双耳交互机制一致，涉及检测来自两只耳朵的一致兴奋输入。没有令人信服的证据表明双耳敏感性是由两耳的锁相兴奋性和抑制性输入的 IPD 依赖性相互作用引起的。尽管双耳相互作用具有一致性，但观察到时间和单耳响应特性的相当大的多样性。 2. 58 个 IPD 敏感单元中的 35 个的单耳和双耳响应被锁相到低频 (< 2.5 kHz) 音调的周期。大多数锁相单元都是双边兴奋的，并且与符合检测模型一致，它们的 IPD 选择性可以根据单耳响应的平均相位之间的差异来预测。其余单元（58 个中的 23 个）没有响应单耳或双耳音调的锁相。大多数非锁相单元无法对一只或双耳的单耳刺激做出反应（单耳无反应单元）。 3.一些IPD敏感单位受到同侧耳或双耳的单耳刺激的抑制。一些单位仅在单耳和双耳音调开始时做出反应。这些单耳抑制和起始单位中的一些但不是全部的反应中存在锁相。 4. 大多数 IPD 敏感神经元出现在内侧上橄榄 (MSO) 细胞柱内或紧邻细胞柱的部位。 IPD 敏感单位也记录在外侧上橄榄 (LSO)、上橄榄旁核 (SPN) 以及在 MSO 周围形成内侧背帽的区域内。双侧兴奋单位集中在 MSO 周围，但也出现在 SPN、背内侧区域和 LSO 中。在 MSO 附近记录了一些单耳无反应单位，但大多数位于内侧背侧区域。单耳抑制单位位于 MSO 细胞柱的内侧边界或 SPN。发病单位定位于 SPN 和内侧背侧区域。 EI 单位仅位于 LSO。（摘要截断为 400 字）
1. We assessed mechanisms of binaural interaction underlying detection of interaural phase disparity (IPD) by recording single-unit responses in the superior olivary complex (SOC) of the anesthetized gerbil (Meriones unguiculatus). Binaural responses were obtained from 58 IPD-sensitive single units, 44 of which were histologically localized. Monaural responses were also obtained for 52 of 58 IPD-sensitive units. Additionally, responses were recorded from 16 units (best frequency < 2.4 kHz) in lateral SOC that were excited by ipsilateral stimulation and inhibited by contralateral stimulation (EI), none of which was IPD sensitive. Our results are consistent with a mechanism of binaural interaction involving detection of coincident excitatory inputs from the two ears. There was no compelling evidence of binaural sensitivity arising from IPD-dependent interactions of phase-locked excitatory and inhibitory inputs from the two ears. Despite the uniformity of binaural interactions, considerable diversity of temporal and monaural response properties was observed. 2. Monaural and binaural responses of 35 of 58 IPD-sensitive units were phase locked to the period of low-frequency (< 2.5 kHz) tones. Most phase-locking units were bilaterally excitable and, consistent with the coincidence-detection model, their IPD selectivity could be predicted from the difference between the mean phases of the monaural responses. The remaining units (23 of 58) did not phase lock in response to monaural or binaural tones. Most non-phase-locking units failed to respond to monaural stimulation of one or both ears (monaurally unresponsive units). 3. Some IPD-sensitive units were inhibited by monaural stimulation of the ipsilateral ear or both ears. A few units responded only at the onset of monaural and binaural tones. Phase locking was present in responses of some, but not all, of these monaurally inhibited and onset units. 4. Most IPD-sensitive neurons were encountered at sites within or immediately adjacent to the cell column of the medial superior olive (MSO). IPD-sensitive units were also recorded in the lateral superior olive (LSO), in the superior paraolivary nucleus (SPN), and within a region forming a medial-dorsal cap around MSO. Bilaterally excitable unites were concentrated around MSO, but were also encountered in SPN, the medial-dorsal region, and LSO. Some monaurally unresponsive units were recorded in the vicinity of the MSO, but most were located in the medial-dorsal region. Monaurally inhibited units were localized to the medial border of the MSO cell column or to SPN. Onset units were localized to SPN and the medial-dorsal region. EI units were located exclusively in LSO.(ABSTRACT TRUNCATED AT 400 WORDS)