Local neuronal circuits that may shape the discharge patterns of inferior collicular neurons
Local neuronal circuits that may shape the discharge patterns of inferior collicular neurons
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DOI：
10.1007/s12264-013-1346-7
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发表时间：
2013-06
影响因子：
5.6
通讯作者：
Z. Fu;Huixian Mei;Liang Cheng;Jing Bai;Jia Tang;P. Jen;Qicai Chen
中科院分区：
文献类型：
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作者：
Z. Fu;Huixian Mei;Liang Cheng;Jing Bai;Jia Tang;P. Jen;Qicai Chen
听觉中枢神经元的放电模式编码有关声音的信息。然而，很少有研究集中在使用细胞内记录技术形成放电模式的突触机制上。在这里，我们使用细胞内记录来研究下丘(IC)神经元的放电模式，以进一步阐明放电模式形成的机制。在活体细胞内记录条件下，对18只健康成年小鼠(Mus musculus，Km)的66个IC神经元进行了自由场刺激下的记录。其中58个神经元对听觉刺激产生阵发性动作电位，其余8个神经元仅产生局部反应，如兴奋性或抑制性突触后电位(n=4)。根据AP和阈值下反应，可将放电模式分为7种类型：相性(24/58，41.4%)、阵发性(8/58，13.8%)、间歇性(4/58，6.9%)、间歇性(1/58，1.7%)、斩波型(2/58，3.4%)、原始性强直(14/58，24.1%)和声诱导抑制性(5/58，8.6%)。我们的结论是：(1)IC神经元至少表现出7种不同的放电模式；(2)抑制参与了大多数IC神经元的放电模式的形成，并在模式的塑造中发挥了作用，但初级类紧张性模式不是由抑制形成的；(3)局部神经回路是形成IC神经元放电模式的可能的结构基础，可在IC或低级听觉结构中形成。
The discharge patterns of neurons in auditory centers encode information about sounds. However, few studies have focused on the synaptic mechanisms underlying the shaping of discharge patterns using intracellular recording techniques. Here, we investigated the discharge patterns of inferior collicular (IC) neurons using intracellular recordings to further elucidate the mechanisms underlying the shaping of discharge patterns. Underin vivointracellular recording conditions, recordings were obtained from 66 IC neurons in 18 healthy adult mice (Mus musculus, Km) under free fi eld-stimulation. Fiftyeight of these neurons fi red bursts of action potentials (APs) to auditory stimuli and the remaining eight just generated local responses such as excitatory (n= 4) or inhibitory (n= 4) postsynaptic potentials. Based on the APs and subthreshold responses, the discharge patterns were classifi ed into seven types: phasic (24/58, 41.4%), phasic burst (8/58,13.8%), pauser (4/58, 6.9%), phasic-pauser (1/58, 1.7%), chopper (2/58, 3.4%), primary-like tonic (14/58, 24.1%) and sound-induced inhibitory (5/58,8.6%). We concluded that (1) IC neurons exhibit at least seven distinct discharge patterns; (2) inhibition participates in shaping the discharge pattern of most IC neurons and plays a role in sculpting the pattern, except for the primary-like tonic pattern which was not shaped by inhibition; and (3) local neural circuits are the likely structural basis that shapes the discharge patterns of IC neurons and can be formed either in the IC or in lower-level auditory structures.