The electrophysiological response of chorda tympani nerve to taste stimuli in rats with conditioned taste aversion to saltiness

doi:10.12047/j.cjap.5768.2019.051

Abstract

Abstract: 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.

Key words: conditioned taste aversion, chorda tympani, taste, rat

LI La-mei, LIAO Ying-ying, JIANG En-she. The electrophysiological response of chorda tympani nerve to taste stimuli in rats with conditioned taste aversion to saltiness[J]. CJAP, 2019, 35(3): 239-244.

References

[1] Welzl H, D'Adamo P, Lipp HP. Conditioned taste aversion as a learning and memory paradigm[J]. Behav Brain Res, 2001, 125 (1-2): 205-213.
[2] Yamamoto T, Nagai T, Shimura T, et al. Roles of chemical mediators in the taste system[J]. Jpn J Pharmacol, 1998, 76 (4): 325-348.
[3] Swank MW, Bernstein IL. c-Fos induction in response to a conditioned stimulus after single trial taste aversion learning[J]. Brain Res, 1994, 636 (2): 202-208.
[4] Grancha ML, Navarro M, Cubero I, et al. Induction of a brainstem correlate of conditioned taste aversion expression: role of the pontine parabrachial nucleus[J]. Behav Brain Res, 2002, 131 (1-2): 205-209.
[5] Reilly S, Bornovalova MA. Conditioned taste aversion and amygdala lesions in the rat: a critical review[J]. Neurosci Biobehav Rev, 2005, 29 (7): 1067-1088.
[6] Ninomiya Y, Funakoshi M. Amiloride inhibition of responses of rat single chorda tympani fibers to chemical and electrical tongue stimulations[J]. Brain Res, 1988, 451 (1-2): 319-325.
[7] Sakamoto T, Fujii A, Saito N, et al. Alteration of amiloride-sensitive salt taste nerve responses in aldosterone/NaCl-induced hypertensive rats[J]. Neurosci Res, 2016, 108: 60-66.
[8] Bernstein IL, Taylor EM. Amiloride sensitivity of the chorda tympani response to sodium chloride in sodium-depleted Wistar rats[J]. Behav Neurosci, 1992, 106 (4): 722-725.
[9] 蒋恩社, 闫剑群, 宋新爱. 味觉刺激与内脏刺激对大鼠孤束核FOS表达的影响[J]. 神经解剖学杂志, 2002, 18(4): 342-346.
[10]蒋恩社, 闫剑群, 宋新艾. 味觉刺激和内脏刺激对大鼠臂旁核c-Fos表达的影响[J]. 西安交通大学学报(医学版), 2003, 24(1): 20-23.
[11]蒋恩社, 闫剑群, 康怡, 等. 内脏不适刺激对大鼠不同味觉溶液摄食的影响[J]. 中国应用生理学杂志, 2003, 19(3): 255-256.
[12]Ninomiya Y. Reinnervation of cross-regenerated gustatory nerve fibers into amiloride-sensitive and amiloride-insensitive taste receptor cells[J]. Proc Natl Acad Sci U S A, 1998, 95 (9): 5347-5350.
[13]吕波, 闫剑群, 陈坷, 等. 低钠饮食性缺钠对大鼠咸味觉敏感性的影响[J]. 西安交通大学学报(医学版), 2011, 32 (6): 695-700.
[14]蒋恩社, 靳永萍, 范媛媛, 等. 多功能鼠类头颈部手术头部固定仪[P]. 中华人民共和国国家知识产权局, 中国, 2015.
[15]Jiang E, Blonde G, Garcea M, et al. Greater superficial petrosal nerve transection in rats does not change unconditioned licking responses to putatively sweet taste stimuli[J]. Chem Senses, 2008, 33 (8): 709-723.
[16]Blonde GD, Garcea M, Spector AC. The relative effects of transection of the gustatory branches of the seventh and ninth cranial nerves on NaCl taste detection in rats[J]. Behav Neurosci, 2006, 120 (3): 580-589.
[17]Golden GJ, Ishiwatari Y, Theodorides ML, et al. Effect of chorda tympani nerve transection on salt taste perception in mice[J]. Chem Senses, 2011, 36 (9): 811-819.
[18]St John SJ, Markison S, Guagliardo NA, et al. Chorda tympani transection and selective desalivation differentially disrupt two-lever salt discrimination performance in rats[J]. Behav Neurosci, 1997, 111 (2): 450-459.
[19]Mungarndee SS, Lundy RF, Norgren R. Central gustatory lesions and learned taste aversions: unconditioned stimuli[J]. Physiol Behav, 2006, 87 (3): 542-551.
[20]康怡, 闫剑群, 黄涛. 损毁大鼠杏仁中央核对不同味觉溶液摄入的影响[J]. 中国应用生理学杂志, 2004, 20(3): 276-279.
[21]Jiang E, Yu D, Feng Z. Subdiaphragmatic vagotomy reduces intake of sweet-tasting solutions in rats[J]. Neural Regen Res, 2013, 8 (17): 1560-1567.