A Comparative Study On The Difference Of Spatial Memory Ability Of Rodents With Different Food Hoarding Preferences

Food hoarding is one of the most important behaviors of rodents.According to the spatial distribution characteristics of food hoarding sites,the food hoarding patterns of rodents can be mainly divided into two types: scatter-hoarding and larder-hoarding.Scatter-hoarding is defined as hoarders build many small hoarding sites in a large space,while the larder-hoarding is the hoarders hoard a large amounts of food in one or limited hoarding sites.The memory of hoarding food is spatial in nature,so only the hoarders are more familiar with their food hoarding sites they can have more advantages in retrieving the hoarded food,and the food hoarding will be meaningful.The food hoarding behavior of rodents is closely related to spatial memory,and individuals with scatter-hoarding may have stronger spatial memory ability.However,at present,there is still a lack of systematic research and deep understanding of the relationship between food hoarding patterns and spatial memory,and the neural mechanisms of food hoarding patterns and spatial memory are also unclear.Therefore,this paper aims at three kinds of rodents: Apodemus agrarius,Cricetulus triton and mice.The patterns of food hoarding and retrieval were determined by food hoarding experiment.The spatial exploration behavior of rodents with different food preference was determined by open field experiment.The spatial memory of rodents with different food preference was determined by maze and other behavioral experiments.The BDNF(brain derived neurotrophic factor)/ Trk B(Tyrosine receptor kinase B)pathway in hippocampus of rodents with different food preferences were measured by Western blot and real-time fluorescent quantitative PCR,to explore the relationship between food hoarding patterns and spatial memory,and this study will provide references for revealing the neural mechanism of food hoarding behavior in rodents.The main results are as follows:1.Food hoarding and retrieving of rodents with different food hoarding preferencesThe results of food hoarding experiment showed that Apodemus agrarius had strong scatter-hoarding and weak larder-hoarding preferences,Cricetulus triton had strong larder-hoarding and weak scatter-hoarding preferences,and mice had no-hoarding and weak larder-hoarding preferences.The food retrieving and re-hoarding ability of Apodemus agrarius with stronger scatter-hoarding preference was better than that of Apodemus agrarius with weaker scatter-hoarding preference.2.Differences in spatial exploration behavior of rodents with different food hoarding preferencesThe results of open field experiment showed that the spatial exploration ability of scatter-hoarding rodents was better than that of larder-hoarding and no-hoarding,and scatter-hoarding rodents were more inclined to explore the central area of open field.The time and distance proportion of movement in the central area of scatter-hoarding rodents was higher than that of larder-hoarding and no-hoarding,but the difference was not significant,indicating that the food hoarding preferences of rodents were not significantly related to their exploration ability.3.Differences in spatial memory of rodents with different food hoarding preferencesThe spatial memory of scatter-hoarding rodents was better than that of larder-hoarding and no-hoarding rodents.The results of new object recognition and new location recognition show that the scatter-hoarding rodents have higher discrimination index of the new object / new location.The study of Y-maze spontaneous alternation experiment showed that the alternation rate of Apodemus agrarius in scatter-hoarding was higher than that in larder-hoarding and no-hoarding,and the difference was significant.Morris water maze experiment found that individuals with scatter-hoarding crossed the platform more times than those with other food hoarding preferences.These experiments showed that there was a close relationship between spatial memory and food hoarding patterns of rodents.4.The relationship between food hoarding patterns and BDNF/Trk B pathway in hippocampusThe differences of BDNF and Trk B gene expression,BDNF and Trk B protein expression in hippocampus of Apodemus agrarius with different hoarding preferences were studied.The results showed that BDNF m RNA and Trk B m RNA expression,BDNF and Trk B protein expression of scatter-hoarding preferences were higher than those of larder-hoarding and no-hoarding preferences,which indicated that the hippocampal BDNF/Trk B pathway of rodents was closely related to their food hoarding behavior.Conclusion:In this study,three kinds of rodents were used for parallel experiments to reveal the relationship between spatial memory and food hoarding preferences.Food hoarding preferences is closely related to its spatial memory ability of rodents,but its spatial exploration ability is weaker;the spatial memory ability of scattere-hoarding is stronger,and the expression of hippocampal BDNF/Trk B genes is also higher.It means that there is a close relationship between food hoarding behavior,spatial cognition and hippocampal BDNF/Trk B pathway.