Frequency Effect On Auditory Fear Memory Generalization And Mechanism Research

Memory and generalization are the higher cognitive functions of the brain.As information is repeatedly retrieved and recoded in different environments,memory usually becomes less detailed and specific,generalizations occur.How memory is extracted has always been a problem that the neuroscience research needs to solve.The retrieval of memory is divided into accurate retrieval of memory and generalization retrieval of memory.However,the accurate retrieval of memory is usually rare,it is difficult to recall memory completely.Accurate retrievals of memories can only be fully reproduced under laboratory conditions.There will always a loss of some detail,the generalization retrieval has always been the main way of memory retrieval.Firstly,in order to explore the relationship between auditory generalization and context generalization,the tone of 5kHz was used for training and 20kHz tone for auditory generalization retrieval,and the similar but different from the training context is used as the context generalization retrieval.It is found that there are significant development differences between the auditory generalization and the context generalization.Then,using two different frequencies as training tone,which the generalization performance of 5kHz training and 20kHz retrieval was significantly better than that using 20kHz training and 5kHz retrieval.This suggests that tone frequency may be an important factor affecting auditory generalization.Then,in order to further explore the influence of frequency on auditory generalization,the tone of 5kHz was used as the training tone,and different tone frequencies were retrieved to explore the influence of frequency on the auditory generalization.The results show that the mouse more easier to form a generalization with high frequency tone.For the time development of the auditory generalization,the tone of 5kHz is used as the training tone,and the tone of 10kHz is used as the generalization tone.The auditory generalization may be formed after learning and may maintain for at least seven days.Then to explore the brain mechanism of auditory generalization,c-Fos immunohistochemical immediately labeling of active neurons was used to analyze the activated brain regions of high frequency generalization retrieval and the low frequency generalization retrieval.It was found that there were significant differences in the clusters of c-Fos positive cells in different brain regions at the whole brain level.The analysis of same brain regions activated by c-Fos were retrieval by different frequency generalization,and it was found that the number of c-Fos positive cells activated by different frequency in thalamus,amygdala,cortex and its subregions was significantly different.These results indicate that these brain regions may be the nodal brain regions that regulate auditory generalization.After that,h M3 Dq virus was used to specifically activate the brain regions with reduced cell number activated by c-Fos,and h M4 Di virus was used to specifically inhibit the brain regions with increased cell number activated by c-Fos.Finally,it was found that when Au1 was inhibited,auditory generalization was reduced,and memory was not affected.Other brain regions were inhibited or activated,and there was no significant change in auditory generalization and memory.Further verification by photogenetic also confirmed the node status of Au1.Our results lay a foundation for the study of generalized retrieval and the mechanism of brain regions,and also provide a new research idea for how to achieve memory retrieval.