Establishment of Visual Fear Conditioning in Long-evans Rats

The neural mechanisms underlying visual information transmission and coding are currently attracting the attention of neuroscience and brain-like computing scholars. The subcortical visual pathway is known to affect fear emotion regulation via the amygdala; however an experimental paradigm for visual fear cognition training remains undefined. In this study,Long-Evans( LE) rats were used to develop an experimental training paradigm for visual cognition-associated fear conditioning based on the Pavlovian conditioning reflex. Simple images were shown on a unilateral screen( conditioned stimulus) were combined with electric foot shocks( unconditioned stimulus). We designed training paradigms and set up an estimated index using the rate of successful active escape. The training results were analyzed using a two-way ANOVA,and curve fitting was used to analyze the influence of decision time between the conditioned stimulus( CS) and unconditioned stimulus( US)on choice behavior. While neither the CS nor US had a significant effect on visual fear association training in LE rats,the decision time duration( CS-US) did have an impact on training. The method described here is most effective in establishing visual fear associations in rats when the( CS-UC) = 10 s. This study describes a new experimental training paradigm for fear conditioning using visual stimuli and a quantitative evaluation standard according to the training mode of visual stimulation graphics. Moreover,it is an efficient paradigm for future study on visual information-processing mechanisms in the subcortical visual pathway during fear conditioning.