Abstract：
The reactions to novelty manifesting in mismatch negativity in the rat brain were studied. During dissociative anesthesia, mismatch negativity-like waves were recorded from the somatosensory cortex using an epidural 32-electrode array. Experimental animals: 7 wild-type Wistar rats and 3 transgenic rats. During high-dose anesthesia, deviant 1,500 Hz tones were presented randomly among many standard 1,000 Hz tones in the oddball paradigm. \"Deviant minus standard_before_deviant\" difference waves were calculated using both the classical method of Naatanen and method of cross-correlation of sub-averages. Both methods gave consistent results: an early phasic component of the N40 and later N100 to 200 (mismatch negativity itself) tonic component. The gamma and delta rhythms power and the frequency of down-states (suppressed activity periods) were assessed. In all rats, the amplitude of tonic component grew with increasing sedation depth. At the same time, a decrease in gamma power with a simultaneous increase in delta power and the frequency of down-states. The earlier phasic frontocentral component is associated with deviance detection, while the later tonic one over the auditory cortex reflects the orienting reaction. Under anesthesia, this slow mismatch negativity-like wave most likely reflects the tendency of the system to respond to any influences with delta waves, K-complexes and down-states, or produce them spontaneously.
摘要：
研究了大鼠大脑中不匹配负性表现出的对新颖性的反应。在分离麻醉期间，使用硬膜外32电极阵列从体感皮层记录不匹配的负波。实验动物:野生型Wistar大鼠7只,转基因大鼠3只。在大剂量麻醉期间，在oddball范例中，在许多标准的1,000Hz音调中随机呈现了1,500Hz的音调。使用Naatanen的经典方法和次平均值的互相关方法计算“偏差减去标准_before_deviant”差波。两种方法都给出了一致的结果：N40的早期阶段性成分和后来的N100至200（错配负电性本身）强直成分。评估了伽马和δ节律功率以及下降状态（抑制活动期）的频率。在所有的老鼠中，强直成分的振幅随镇静深度的增加而增加。同时,伽玛功率的减少，同时增加delta功率和下降状态的频率。较早的相位额中央分量与偏差检测有关，而后来的补品在听觉皮层上反映了定向反应。在麻醉下,这种缓慢不匹配的负波很可能反映了系统对任何影响的响应趋势，K-复合体和下行状态，或者自发地产生它们。
