Cecchetto Claudia, Mahmud Mufti, Vassanelli Stefano
Annu Int Conf IEEE Eng Med Biol Soc. 2015;2015:4721-4. doi: 10.1109/EMBC.2015.7319448.
The rat barrel cortex is a widely used model of information processing in the somatosensory area, thanks to its precise and easily recognizable organization. However, evoked Local Field Potentials (LFPs) generated in the barrel cortex by repetitive deflections of rat whiskers show large variability in shapes and timings. Moreover, anesthetics can deeply affect the profile of evoked responses. This paper presents preliminary report on the variability and the effect of commonly used anesthetics on these signals. We studied representative signal shape characteristics (e.g., latency and amplitude of events) extracted from evoked responses acquired by means of standard Ag/AgCl electrodes from different cortical layers. As an early result, we found significant difference in the latency of the first principal peak of the responses. Under Tiletamine-Xylazine anesthetic, the responses or events of the evoked LFPs occurred later than the ones recorded while urethane was administered. Furthermore, the distributions of the peak latencies in all cortical layers were narrower in case of Urethane. This behavior should be attributed to the different effects of these two anesthetics on specific synaptic receptors and thus on the processing of neural information and the encoding of sensory input along the cortical pathway.
大鼠桶状皮层是体感区广泛使用的信息处理模型，这得益于其精确且易于识别的组织结构。然而，大鼠胡须的重复偏转在桶状皮层中诱发的局部场电位（LFP）在形状和时间上表现出很大的变异性。此外，麻醉剂会深刻影响诱发反应的特征。本文呈现了关于常用麻醉剂对这些信号的变异性及影响的初步报告。我们研究了从不同皮层层通过标准银/氯化银电极获取的诱发反应中提取的代表性信号形状特征（例如，事件的潜伏期和幅度）。作为早期结果，我们发现反应的第一个主峰潜伏期存在显著差异。在替来他明 - 赛拉嗪麻醉下，诱发LFP的反应或事件比给予乌拉坦时记录的反应或事件出现得更晚。此外，在乌拉坦麻醉情况下，所有皮层层的峰值潜伏期分布更窄。这种行为应归因于这两种麻醉剂对特定突触受体的不同作用，进而对神经信息处理以及沿皮层通路的感觉输入编码产生的不同影响。
