Department of Physiology, Third Military Medical University, Chongqing, P. R. China.
Physiol Res. 2011;60(4):687-93. doi: 10.33549/physiolres.932086. Epub 2011 May 16.
Spontaneous activity of cortical neurons exhibits alternative fluctuations of membrane potential consisting of phased depolarization called "up-state" and persistent hyperpolarization called "down-state" during slow wave sleep and anesthesia. Here, we examined the effects of sound stimuli (noise bursts) on neuronal activity by intracellular recording in vivo from the rat auditory cortex (AC). Noise bursts increased the average time in the up-state by 0.81+/-0.65 s (range, 0.27-1.74 s) related to a 10 s recording duration. The rise times of the spontaneous up-events averaged 69.41+/-18.04 ms (range, 40.10-119.21 ms), while those of the sound-evoked up-events were significantly shorter (p<0.001) averaging only 22.54+/-8.81 ms (range, 9.31-45.74 ms). Sound stimulation did not influence ongoing spontaneous up-events. Our data suggest that a sound stimulus does not interfere with ongoing spontaneous neuronal activity in auditory cortex but can evoke new depolarizations in addition to the spontaneous ones.
在慢波睡眠和麻醉期间，皮质神经元的自发活动表现出膜电位的交替波动，包括相位去极化的“上状态”和持续超极化的“下状态”。在这里，我们通过在体大鼠听觉皮层（AC）的细胞内记录，检查了声音刺激（噪声爆发）对神经元活动的影响。与 10 秒的记录持续时间相关，噪声爆发将上状态的平均时间增加了 0.81+/-0.65 秒（范围，0.27-1.74 秒）。自发上事件的上升时间平均为 69.41+/-18.04 毫秒（范围，40.10-119.21 毫秒），而声音诱发的上事件的上升时间明显更短（p<0.001），平均仅为 22.54+/-8.81 毫秒（范围，9.31-45.74 毫秒）。声音刺激不会影响正在进行的自发上事件。我们的数据表明，声音刺激不会干扰听觉皮层中正在进行的自发神经元活动，但除了自发活动外，还可以引发新的去极化。
