Investigate The Difference Between The Vomeronasal System To Sense Pheromone Of Rattus Norvegicus Subspecies And Rattus Tanezumi

Rattus norvegicus and Rattus tanezumi are harmful rats that are closely related to people's lives,and they are the focus of rodent prevention and control.As rodents,their olfactory systems are extremely developed,so chemical communication is their primary mode of communication.The vomeronasal system(VNS)of rodents is mainly responsible for identifying and processing pheromone signals.Some researchers have studied the regulatory effects of pheromones on Rattus norvegicus humiliates(RNH),Rattus norvegicus caraco(RNC),and Rattus tanezumi(RT)based on behavior.This is helpful for rodent prevention and control from the perspective of chemical communication.However,research on the recognition of pheromone signals by VNS in these three types of rats at the cellular and molecular levels remains to be done.In this study,we first investigated the activation of vomeronasal sensory neurons(VSNs)in RNH,RNC,and RT with 2-heptanon,squalene,MUP13,and OBP3,respectively,using calcium imaging technology.The results showed that the vomeronasal organs of the three kinds of experimental rats had significant differences in their sensibility to the same pheromone,and RNH had the strongest sensibility,followed by RNC,and RT had the weakest.At the same time,the results also showed that when different pheromones were applied to the live vomeronasal organ slice preparation of the same animal,the number of activated VSNs also varies.Next,in order to verify whether the above differences still exist in the subsequent central nervous system,we selected 2-heptanone with the highest VSNs activation ratio and MUP13 with the lowest ratio in the calcium imaging experiment.The c-Fos immunohistochemical method was used to study the the brain tissue sections(BNST,PMCo,MeA,VmH,MPA)and accessory olfactory bulb(AOB)tissue sections of the three types of rats.The results showed that the expression of c-Fos immunoreactivity in AOB and the above five brain regions was significantly different in these three types of rats,and the number of c-Fos positive neurons in RNH was the largest,followed by RNC,and the lowest in RT.In addition,different pheromone focused subsequent pathways in the same genus of experimental animals are also different.The number of 2-heptanon activated neurons in the AOB,BNST,and MPA of RNH was significantly higher than that of MUP13.The excitatory effect of 2-heptanon in the AOB,BNST,VmH and MeA of RNC was significantly higher than that of MUP13.In RT,the response intensity of BNST,PMCo and MPA to 2-heptanon signal was significantly higher than MUP13.We deeply study the differences in signal recognition of VNS of RNH,RNC and RT,and provide important evidence for their VNS differentiation.