Enhanced sound perception by widespread-onset neuronal responses in auditory cortex
Enhanced sound perception by widespread-onset neuronal responses in auditory cortex
复制标题
DOI：
10.1162/neco.2007.19.12.3310
复制
发表时间：
2007-12-01
影响因子：
2.9
通讯作者：
Hoshino, Osamu
中科院分区：
文献类型：
--
作者：
Hoshino, Osamu
越来越多的证据表明，听觉皮层神经元对声音刺激表现出预激起始反应和限制性持续反应。当一个声音刺激被呈现给一个受试者时，听觉皮层首先在相对较大的神经元群体中以瞬时放电做出反应，显示出快速发作的反应。随着时间的推移，激活变得局限于一小群优先受刺激驱动的神经元，表现出有限的持续反应。持续性反应被认为在表达刺激的信息方面有一定作用，但持续性起始反应在听觉信息处理中的作用还有待观察。我们对听觉皮层外侧带区域的神经网络模型进行了数值模拟。在这个网络中，动态的细胞集合表达了关于听觉声音的信息。通过中间神经元的直接和间接投射，分别在细胞集合体之间建立了侧向兴奋性和抑制性连接。如果侧兴奋先于侧抑制，则神经元对声音刺激（带通噪声）的广泛传播起始反应在网络上发生，使得起始反应的时间窗口。预激起始反应加速了神经元对感觉刺激的反应时间。动态细胞组装体之间的横向相互作用对于维持正在进行的膜电位接近动作电位产生的阈值是必不可少的，从而也加速了对随后的感觉输入的反应时间。我们认为，prepread发作的神经元反应和正在进行的阈下皮层状态，不同的细胞组装之间的横向突触相互作用的协调是必不可少的，可能会一起工作，以使听觉皮层迅速检测到突然发生的声音从外部环境。
Accumulating evidence suggests that auditory cortical neurons exhibit widespread-onset responses and restricted sustained responses to sound stimuli. When a sound stimulus is presented to a subject, the auditory cortex first responds with transient discharges across a relatively large population of neurons, showing widespread-onset responses. As time passes, the activation becomes restricted to a small population of neurons that are preferentially driven by the stimulus, showing restricted sustained responses. The sustained responses are considered to have a role in expressing information about the stimulus, but it remains to be seen what roles the widespread-onset responses have in auditory information processing. We carried out numerical simulations of a neural network model for a lateral belt area of auditory cortex. In the network, dynamic cell assemblies expressed information about auditory sounds. Lateral excitatory and inhibitory connections were made between cell assemblies, respectively, by direct and indirect projections via interneurons. Widespread-onset neuronal responses to sound stimuli (bandpassed noises) took place over the network if lateral excitation preceded lateral inhibition, making a time widow for the onset responses. The widespread-onset responses contributed to the accelerating reaction time of neurons to sensory stimulation. Lateral interaction among dynamic cell assemblies was essential for maintaining ongoing membrane potentials near thresholds for action potential generation, thereby accelerating reaction time to subsequent sensory input as well. We suggest that the widespread-onset neuronal responses and the ongoing subthreshold cortical state, for which the coordination of lateral synaptic interaction among dissimilar cell assemblies is essential, may work together in order for the auditory cortex to quickly detect the sudden occurrence of sounds from the external environment.