The effect of auditory cortex deactivation on stimulus-specific adaptation in the inferior colliculus of the rat
The effect of auditory cortex deactivation on stimulus-specific adaptation in the inferior colliculus of the rat
复制标题
DOI：
10.1111/ejn.12018
复制
发表时间：
2013-01-01
影响因子：
3.4
通讯作者：
Malmierca, M. S.
中科院分区：
文献类型：
--
作者：
Anderson, L. A.;Malmierca, M. S.
从下丘（IC）到听觉皮层（AC）的中枢听觉通路中的许多神经元对常见刺激的反应不如对罕见刺激的反应强烈。这种现象的起源，称为刺激特异性适应（SSA），仍然不确定。AC向IC发送下行投射，这些投射最密集地终止于已报道的强SSA的背侧、外侧和喙侧IC皮质区域。要调查是否SSA在IC是依赖于AC的产生，我们记录了从单个IC神经元的反应，在一个古怪的范例之前，期间和之后可逆地灭活同侧AC与冷冻环的刺激。虽然IC神经元的基本反应特性的变化是广泛的（89%），SSA敏感性的变化是不太常见的，大约一半的神经元记录显示SSA的显着变化，而另一半保持不变。SSA的变化可以是任何一个方向：18%的人增加了他们的SSA敏感性，而34%的人显示SSA敏感性降低。对于后一组的大多数人来说，皮质失活减少了，但没有消除，显着的SSA水平。只有8个神经元似乎从AC继承SSA，因为它们先前存在的显著水平的SSA在皮层失活期间变得不显著。因此，SSA在IC中的存在通常不依赖于皮质丘投射，这表明AC对于皮质下SSA的产生不是必不可少的;然而，AC可能在皮质下SSA的调制中发挥作用。
Many neurons in the central auditory pathway, from the inferior colliculus (IC) to the auditory cortex (AC), respond less strongly to a commonly occurring stimulus than one that rarely occurs. The origin of this phenomenon, called stimulus-specific adaptation (SSA), remains uncertain. The AC sends descending projections to the IC that terminate most densely upon the dorsal, lateral and rostral IC cortices areas where strong SSA has been reported. To investigate whether SSA in the IC is dependent upon the AC for its generation, we recorded the response from single IC neurons to stimuli presented in an oddball paradigm before, during and after reversibly deactivating the ipsilateral AC with a cryoloop. While changes in the basic response properties of the IC neurons were widespread (89%), changes in SSA sensitivity were less common; approximately half of the neurons recorded showed a significant change in SSA, while the other half remained unchanged. Changes in SSA could be in either direction: 18% enhanced their SSA sensitivity, while 34% showed reduced SSA sensitivity. For the majority of this latter group, cortical deactivation reduced, but did not eliminate, significant SSA levels. Only eight neurons seemed to inherit SSA from the AC, as their pre-existing significant level of SSA became non-significant during cortical deactivation. Thus, the presence of SSA in the IC is generally not dependent upon the corticocollicular projection, suggesting the AC is not essential for the generation of subcortical SSA; however, the AC may play a role in the modulation of subcortical SSA.