Effects of CeA lesions on the initiation and expression of sodium appetite in sodium-deficient rats / 中国应用生理学杂志

OBJECTIVE@#To investigate the effects of central nucleus of amygdala (CeA) lesion on the initiation and expression of sodium appetite in sodium-deficient rats.@*METHODS@#Three groups of SD rats (n=6 in each group) were treated with bilateral CeA lesion, sham lesion or no lesion. After the recovery, the rats were fed with low-sodium diets for 14 days to establish a sodium-deficient rat model. The double-bottle selection in single cage test was used to observe the intake of 0.3 mol/L NaCl and DW in 5 timepoint with 24 hours in sodium-deficient rats. Immunofluorescence staining of aldosterone-sensitive neurons in the nucleus tractus solitarii (NTS)was used to investigate the effect of CeA lesion or not on the activity of aldosterone-sensitive neurons in rats with or without sodium deficiency.@*RESULTS@#After fed with low-sodium diet for14 days, the volume and preference rate of 0.3 mol/L NaCl intake of the rats within 24 h were significantly increased compared with those before low-sodium diet (P＜0.01). The intake volume and the preference rate of 0.3 mol/L NaCl in CeA lesion rats were significantly decreased than those in CeA sham lesion rats and normal rats in the sodium-deficient condition (P＜0.01). The CeA lesion had no effects on the activity of aldosterone-sensitive neurons in NTS in rats with low-sodium diet.@*CONCLUSION@#Low-sodium diet induces an increase in the expression of sodium appetite in rats. CeA lesions inhibit the behavioral expression of sodium appetite in sodium-deficient rats but have no effects on the initiation of sodium appetite in rats with sodium-deficient rats.

The electrophysiological response of chorda tympani nerve to taste stimuli in rats with conditioned taste aversion to saltiness / 中国应用生理学杂志

OBJECTIVE@#To explore the characteristic changes of the peripheral chorda tympanic nerve (CT) electrophysiological responses to salty stimulus and other taste stimuli in rats with the conditioned taste aversion to saltiness.@*METHODS@#Fourteen adult SD male rats were divided into a conditioned taste aversion to salty group (CTA) and a control group (Ctrl) (n=7/group). On the first day of the experiment, rats were given a 0.1 mol/L NaCl intake for 30 min, then, the rats in CTA and Ctrl groups were injected intraperitoneally with 2 ml of 0.15 mol/L LiCl and the same amount of saline respectively. On day 2, 3 and 4, the 30 min consumption of NaCl and distilled water was measured for both groups of rats. On the 4th day after the behavioral test of that day, CT electrophysiological recording experiments were performed on CTA rats and control rats.@*RESULTS@#Compared with the rats in Ctrl group, the electrophysiological characteristics of CT in CTA group rats did not change significantly the responses to the series of NaCl and other four basic taste stimuli (P＞0.05). The amiloride, the epithelial sodium channel blocker, strongly inhibited the response of CT to NaCl in CTA and Ctrl group rats (P＜0.01).@*CONCLUSION@#The electrophysiological responses of CT to various gustatory stimuli do not significantly change in rats after the establishment of conditional taste aversion to the saltiness.

Progress in the effects of injury and regeneration of gustatory nerves on the taste functions in animals / 生理学报

The sensor of the taste is the taste bud. The signals originated from the taste buds are transmitted to the central nervous system through the gustatory taste nerves. The chorda tympani nerve (innervating the taste buds of the anterior tongue) and glossopharyngeal nerve (innervating the taste buds of the posterior tongue) are the two primary gustatory nerves. The injuries of gustatory nerves cause their innervating taste buds atrophy, degenerate and disappear. The related taste function is also impaired. The impaired taste function can be restored after the gustatory nerves regeneration. The rat model of cross-regeneration of gustatory nerves is an important platform for research in the plasticity of the central nervous system. The animal behavioral responses and the electrophysiological properties of the gustatory nerves have changed a lot after the cross-regeneration of the gustatory nerves. The effects of the injury, regeneration and cross-regeneration of the gustatory nerves on the taste function in the animals will be discussed in this review. The prospective studies on the animal model of cross-regeneration of gustatory nerves are also discussed in this review. The study on the injury, regeneration and cross-regeneration of the gustatory nerves not only benefits the understanding of mechanism for neural plasticity in gustatory nervous system, but also will provide theoretical basis and new ideas for seeking methods and techniques to cure dysgeusia.