基于自然图像认知的大鼠上丘神经元恐惧信息编码机制

为了探究大鼠对自然图像的认知效果以及在自然图像认知过程中上丘(superior colliculus, SC)神经元的恐惧信息编码机制,采用条件性恐惧联结训练方法,设计了基于三种不同情感属性自然图像的实验方案(恐惧:"蛇"、中性:"树"、奖励:"鼠粮"),对大鼠进行了视觉认知训练。首先,从行为学分析了大鼠对具有不同情感意义自然图像的认知效果;其次,采用第一动作电位延时(first spike latency, FSL)以及Spike(峰电位)平均发放率两种编码方法,研究了大鼠上丘神经元在自然图像认知学习过程中的恐惧信息编码机制。结果表明,大鼠对奖励、恐惧、中性三种图像的抉择正确率分别在第6、22、26 d达到了75%基准线。训练后,在恐惧图像的刺激作用下,大鼠上丘神经元集群的平均FSL值显著低于训练前,且神经元集群的Spike发放率显著提高。这些结果揭示了恐惧信息能够激活大鼠上丘脑区,并通过SC脑区实现恐惧信息快速传递与表征。

Study on the Coding Mechanism of Fear Information in Rat Superior Colliculus Neurons Based on Natural Image Cognition

In order to explore the cognitive effects of rats on natural images and the fear information coding mechanism of superior colliculus (SC) neurons in natural image cognition. The conditional fear connection training method was used to design an experimental scheme based on natural images of three different emotional attributes (fear: "snake", neutral: "tree", reward: "rat food"). And the rats were trained in visual cognition. Firstly, the cognitive effects of rats on natural images with different emotional meanings were analyzed from behavioristics. Secondly, the first spike latency (FSL) and Spike mean firing rate were used to study the coding mechanism of fear information in rat superior colliculus neurons in the process of natural image cognitive learning. The results showed that the correct decision rate of reward, fear and neutral images in rats reached 75% baseline on the 6th, 22nd and 26th day, respectively. After training, under the stimulation of the fear image, the average FSL value of the rat superior colliculus neuron cluster was significantly lower than that before training, and the Spike mean firing rate of the neuron cluster was significantly increased. These results revealed that the superior colliculus can be activated by fear information, and the fear information can be rapidly transmitted and characterized through the SC brain region.