Taste response variability and temporal coding in the nucleus of the solitary tract of the rat
Taste response variability and temporal coding in the nucleus of the solitary tract of the rat
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DOI：
10.1152/jn.00177.2003
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发表时间：
2003-09-01
影响因子：
2.5
通讯作者：
Victor, JD
中科院分区：
文献类型：
--
作者：
Di Lorenzo, PM;Victor, JD
脑干中味觉编码的理论一直基于这样的想法，即味觉反应随时间被整合，而不考虑味觉诱发的尖峰序列的时间结构。在本实验中，跨刺激重复的反应率的可靠性和潜在的贡献的时间编码的味觉刺激的歧视进行了检查。重复呈现代表四种基本味觉品质的味觉刺激，并记录麻醉大鼠孤束核（NTS）单细胞的电生理反应。重复四种促味剂的阻断，只要细胞保持分离。记录了19个细胞，每个刺激重复8至27次。对给定促味剂的响应幅度在一些NTS细胞内变化很大。这影响了对给定细胞的调谐宽度和最佳刺激的确定。基于两个家庭的指标的信息论方法的贡献的尖峰时间和模式的interspike间隔的味觉刺激的歧视进行了评估。尖峰时间显着贡献的10个（53%）细胞的味觉品质的歧视。这种贡献在响应的最初2秒期间尤其显著。那些在重复味觉刺激时表现出最可变的放电率的细胞往往表现出最大的时间编码贡献。这些结果表明，除了反应率，反应的时间参数可以传达信息的味觉刺激在NTS。
Theories of taste coding in the brain stem have been based on the idea that taste responses are integrated over time without regard to the temporal structure of the taste-evoked spike train. In the present experiment, the reliability of response rate across stimulus repetitions and the potential contribution of temporal coding to the discrimination of taste stimuli was examined. Taste stimuli representing the four basic taste qualities were presented repeatedly, and electrophysiological responses were recorded from single cells in the nucleus of the solitary tract (NTS) of anesthetized rats. Blocks of the four tastants were repeated for as long as the cell remained isolated. Nineteen cells were recorded with between 8 and 27 repetitions of each stimulus. Response magnitude to a given tastant varied widely within some NTS cells. This impacted the determination of both the breadth of tuning and best stimulus for a given cell. The contribution of spike timing and the pattern of interspike intervals to discrimination of taste stimuli was evaluated by an information-theoretic approach based on two families of metrics. Spike timing significantly contributed to the discrimination of taste qualities in 10 of 19 (53%) cells. This contribution was especially notable during the initial 2 s of the response. Those cells that showed the most variable firing rates in response to repetition of taste stimuli tended to show the largest contribution of temporal coding. These results suggest that, in addition to response rate, the temporal parameters of responses may convey information about taste stimuli in the NTS.