The Study On Gustatory Electrophysiological Responsive Property Of The Chorda Tympani Nerve In The Conditionded Salty Taste Aversion Rats And Their Changes On Sodium Appetite

Conditioned taste aversion(CTA),a self protective mechanism that animals in the complex nature of food supply developed and was built to avoid feeding again harmful substances.The establishment of CTA cooperated by the central nervous system and the peripheral nervous system.At present,most of the researches about CTA are concerned with the study of the central nervous system,and it is unknown whether the peripheral gustatory nervous system is involved.Sodium depletion will give rise to a series of internal secretion changes,by activating the specific brain circuitry to produce sodium appetite and with the change of salty taste function to regulate sodium ingestion and recover body sodium balance.Sodium depletion will arouse the change of taste reflection,when sodium desire becomes stronger,sodium depletion animals will demonstrate the growing fondness for hypertonic salty solution and the characteristic of reward response.Nevertheless,when sodium depletion rats feel disgust for salty taste,what is the regulation of rat organism? Whether salty taste will change or not is a question worth of discussing.Objective1.To explore after the establishment of conditioned taste aversion,whether the peripheral taste system of chorda tympani nerve takes part in the rats' mechanism change for salty taste aversion.2.To explore after rats establish conditioned taste aversion to salty taste,under the condition of sodium depletion and the enhancement of sodium appetite,rats' choice and the effect of salty sodium disgust on sodium appetite.Method1.The experimental method of the first part: establish the experimental group and the control group model of conditioned taste aversion model.Then,anesthesia was weighed to find and separate the Chorda tympani nerve under the microscope.In the case of not hurting chorda tympani nerve,strip nerve sheath,hang it in the monopolar electrode,and give different tastes on the lingual surface.Use electrophysiology to record electrophysiological changes of the tympanic nerve to different tastes.2.The experimental method of the second part: to use three groups rats of different treatment factors to discuss the regulation of taste aversion to sodium appetite.The experimental group: to establish taste aversion model and rapid sodium removal;the control group 1: to establish taste aversion model;the control group of 2: to establish a rapid sodium control.Through three groups of rats with different treatment factors to explore their sodium appetite regulation.This experiment use SPSS 17 statistical software to analyze the data.Descriptive statistical analysis method(mean,standard deviation)was used to describe the data.Two independent samples t test,variance analysis,repeated measurement of general linear model,single factor were used to statistical analysis.Statistical test level ? = 0.05,P values were two-sided probability.Result1.After rats established conditioned taste aversion to salty taste,their chorda tympani nerve reaction characteristiCS of different concentrations of NaCl didn't change significantly.2.After rats established conditioned taste aversion to salty taste,the characteristiCS of chorda tympani nerve on the other four kinds of taste stimuli did not change significantly.3.There were significant differences among three different treatment factors ——(P<0.05).4.There were no significant differences between 0.1M and 0.3M ——(P>0.05)in the experimental group,but there was significant difference between the two groups in the control of NaCl with different concentrations of NaCl ——(P<0.05).5.The difference of daily preferences showed that when experimental group at 0.1M NaCl,the preferences tend to CTA group;at 0.3M Na Cl,the preferences of the experimental group tended to be faster in the Na group.Conclusion1.After rats established conditioned taste aversion,the transformation from love to hate on salty,is mainly because the central nervous system plays a role in taste,while the peripheral taste system as the main information transmission,plays very little in the transformation of preference for salty taste.2.Rats' aversion to salty taste could attenuate the sodium desire induced by sodium deficiency in vivo.Conversely,sodium appetite induced by sodium deficiency in vivo could weaken the aversion to salty taste and increase the intake of sodium salt.