Deactivation of the inferior colliculus by cooling demonstrates intercollicular modulation of neuronal activity.
Deactivation of the inferior colliculus by cooling demonstrates intercollicular modulation of neuronal activity.
复制标题
DOI：
10.3389/fncir.2012.00100
复制
发表时间：
2012
影响因子：
3.5
通讯作者：
Rees A
中科院分区：
文献类型：
--
作者：
Orton LD;Poon PW;Rees A
穿过脑干的听觉通路以围绕中线的镜像方式双边组织，并且两侧在多个层面上相互连接。最突出的互连点之一是下丘连合 (CoIC)。解剖学研究表明，这些纤维按照下丘 (IC) 的音位组织进行相互连接，并且连合处同时包含兴奋性纤维和尽管较少的抑制性纤维。这些连接在声音处理中的作用很大程度上是未知的。在这里，我们描述了一种在麻醉豚鼠中解决这个问题的方法。我们使用放置在一个 IC 上的冷冻回路来产生可逆失活，同时记录两个 IC 中对声音的电生理反应。我们记录了冷却前、冷却中和冷却后的单个单元、多单元簇和局部场电位 (LFP)。冷却的程度和扩散是通过放置在 IC 和其他听觉结构中的热电偶来测量的。足以消除起火的冷却仅限于与冷冻回路接触的 IC。其他听觉脑干结构（包括对侧 IC 和耳蜗）的温度受到的影响最小。冷却至 20°C 以下可减少或消除频率层中与高达约 8 kHz 的特征频率相对应的深度处的动作电位的激发。随着单单元发射和 LFP 的变化，神经活动的调节也发生在未冷却的 IC 中。向 IC 发出丘系传入输入信号的 LFP 成分在冷却时幅度或潜伏期几乎没有变化，而后面的成分（可能反映了丘脑间和丘内处理）在形式和幅度上表现出显着变化。我们得出的结论是，cryoloop 是选择性停用豚鼠中一个 IC 的有效方法，并证明 IC 中的听觉处理受到另一个 IC 的强烈影响。
The auditory pathways coursing through the brainstem are organized bilaterally in mirror image about the midline and at several levels the two sides are interconnected. One of the most prominent points of interconnection is the commissure of the inferior colliculus (CoIC). Anatomical studies have revealed that these fibers make reciprocal connections which follow the tonotopic organization of the inferior colliculus (IC), and that the commissure contains both excitatory and, albeit fewer, inhibitory fibers. The role of these connections in sound processing is largely unknown. Here we describe a method to address this question in the anaesthetized guinea pig. We used a cryoloop placed on one IC to produce reversible deactivation while recording electrophysiological responses to sounds in both ICs. We recorded single units, multi-unit clusters and local field potentials (LFPs) before, during and after cooling. The degree and spread of cooling was measured with a thermocouple placed in the IC and other auditory structures. Cooling sufficient to eliminate firing was restricted to the IC contacted by the cryoloop. The temperature of other auditory brainstem structures, including the contralateral IC and the cochlea were minimally affected. Cooling below 20°C reduced or eliminated the firing of action potentials in frequency laminae at depths corresponding to characteristic frequencies up to ~8 kHz. Modulation of neural activity also occurred in the un-cooled IC with changes in single unit firing and LFPs. Components of LFPs signaling lemniscal afferent input to the IC showed little change in amplitude or latency with cooling, whereas the later components, which likely reflect inter- and intra-collicular processing, showed marked changes in form and amplitude. We conclude that the cryoloop is an effective method of selectively deactivating one IC in guinea pig, and demonstrate that auditory processing in the IC is strongly influenced by the other.
登录
查看更多内容
影响因子：
3
作者：
Ben Coomber;Edwards, Darren;Palmer, Alan R.
通讯作者：
Palmer, Alan R.
影响因子：
2.4
作者：
HEFFNER, R;HEFFNER, H;MASTERTON, B
通讯作者：
MASTERTON, B
影响因子：
5.7
作者：
Dorr, A.;Sled, J. G.;Kabani, N.
通讯作者：
Kabani, N.
影响因子：
5.5
作者：
Hardingham, NR;Larkman, AU
通讯作者：
Larkman, AU
影响因子：
3.3
作者：
Girardin, C. C.;Martin, K. A. C.
通讯作者：
Martin, K. A. C.