Brain electrical activity on temporal discrimination in rats.

我们研究了大鼠脑电活动对定时行为的影响。本研究探讨了大鼠大脑在时间分辨任务中的功能。在本实验研究中，动物在操作室中使用峰间隔（PI） 30秒程序进行训练，其中包括固定间隔（FI） 30秒试验和探针试验。FI 30-s试验包括食物颗粒强化，在张力刺激开始后30多s出现第一个杠杆按压反应，刺激终止。探针试验无强化反应，音调刺激持续90 s。在探针试验中，杆压响应的3-s周期有一个明显的峰值点。该方法是研究大鼠生物钟的一种有效方法。随着加固时间的增加，峰值时间在30-s左右。在自我启动组中，试验开始时的应答数超过了对照组。但峰值点与自主启动对照组相同。随着加固时间的增加，峰值时间在30 ~ 30秒左右。该图有一个峰值点，表示回归曲线与泊松函数拟合的峰值。然后将电极植入大鼠大脑。采用PI法测定大鼠海马脑电图（EEG）。电极被植入大脑皮层下区域。海马和纹状体区的脑电图功率显示海马θ节律与定时行为模式相关。这些结果表明，海马体和纹状体振荡在大脑中具有重要的时序机制。海马体和纹状体可能在动物对时间流逝的估计中起着非常重要的作用。

We studied the electrical activity of the brain on timing behavior in rats. This study was investigated for the function of the brain on the temporal discrimination task in rats. In this experimental study, animals were trained in operant chambers using the peak-interval (PI) 30-s procedure that included fixed interval (FI) 30-s trials and probe trials. The FI 30-s trials consisted of a food pellet reinforcement that presented by the first lever press response more than 30-s after the onset of tone stimulus, and the stimulus was terminated. The probe trials delivered no reinforcement with responses and tone stimulus lasted for 90-s. The 3-s bin of lever press responses on probe trials showed a clear peak point. This PI procedure is a useful procedure to investigate about timing in rats.The peak time corresponded to near the 30-s with reinforcement time. In the self-start group, the number of responses at the beginning of the trials exceeded that of the control group. But the peak point was the same as the autonomic start control group. The peak time corresponded to near the 30-s with reinforcement durations. The graph had a peak point that showed the peak of the regression curve fitting with the Poisson function. Then the electrodes were implanted in the rat brain. We measured the hippocampal electroencephalography (EEG) with performing PI procedure in rats. The electrodes were implanted in the sub-cortex brain areas. The EEG power of the hippocampus and striatum region showed hippocampal theta rhythm correlation with timing behavior patterns. These results suggest that the hippocampus and striatum oscillations are important with timing mechanism in the brain. The hippocampus and striatum may play a very important role to estimate the passage of the time in living animals.