Smith J C, Miller I J, Krimm R F, Nejad M S, Beidler L M
Florida State University, Department of Psychology, Tallahassee 32306.
Physiol Behav. 1988;44(4-5):435-44. doi: 10.1016/0031-9384(88)90303-4.
The chorda tympani nerve (CT) innervates the fungiform papillae on the tip of the tongue and has been considered an important nerve for the sense of taste. The CT also contains the parasympathetic supply to the submaxillary and sublingual salivary glands. Therefore, changes in taste or feeding behavior following bilateral sections of CT are caused by both degeneration of fungiform papillae and the inevitable partial desalivation of the rat. In the present experiments we compared the effects of bilateral chorda tympani nerve sections with extirpation of submaxillary and sublingual glands on daily home cage eating and drinking patterns in the rat. Before and after surgery we analyzed the daily eating and drinking patterns, including such measures as intake, bout number, bout length, interbout interval and rate of consumption during bouts. The results of desalivation and bilateral CT sections were indistinguishable. The most profound change was that eating bout duration was increased following surgery. Since food intake did not increase, the results indicate a marked loss in eating efficiency over the daily ingestion periods. Although the eating patterns of desalivated and chorda tympani sectioned rats are quite similar, the evidence is not compelling that they have the same physiological basis. A second experiment was designed to test the hypothesis that the atypical eating patterns observed following bilateral sectioning of CT were the direct result of partial desalivation resulting from the denervation of the salivary glands. In this experiment a unilateral section was made of one CT and it was shown that the eating behavior was not affected. Then the contralateral submaxillary and sublingual salivary glands were removed. This resulted in a six-fold increase in feeding bout length. In all cases a unilateral CT section combined with extirpation of the contralateral salivary glands resulted in rats whose eating behavior was indistinguishable from the earlier data following either the bilateral CT sections or bilateral desalivations. The conclusion is drawn that the eating irregularities noted following bilateral CT sections result from this partial desalivation. CT sections were verified by taste bud counts in the fungiform papillae and histological examinations were made of salivary glands in rats receiving CT sections.
鼓索神经（CT）支配舌尖的菌状乳头，一直被认为是味觉的重要神经。鼓索神经还包含至颌下腺和舌下腺的副交感神经供应。因此，双侧切断鼓索神经后味觉或摄食行为的改变是由菌状乳头的退化以及大鼠不可避免的部分唾液分泌减少共同引起的。在本实验中，我们比较了双侧鼓索神经切断与切除颌下腺和舌下腺对大鼠每日笼内进食和饮水模式的影响。手术前后，我们分析了每日的进食和饮水模式，包括摄入量、进食次数、进食时长、进食间隔和进食期间的消耗速率等指标。唾液分泌减少和双侧鼓索神经切断的结果难以区分。最显著的变化是手术后进食时长增加。由于食物摄入量并未增加，结果表明在每日摄食期间进食效率显著降低。尽管唾液分泌减少的大鼠和鼓索神经切断的大鼠的进食模式非常相似，但没有令人信服的证据表明它们具有相同的生理基础。第二个实验旨在检验以下假设：双侧切断鼓索神经后观察到的异常进食模式是唾液腺去神经支配导致部分唾液分泌减少的直接结果。在这个实验中，单侧切断一条鼓索神经，结果表明进食行为未受影响。然后切除对侧的颌下腺和舌下腺。这导致进食时长增加了六倍。在所有情况下，单侧鼓索神经切断并切除对侧唾液腺的大鼠的进食行为与早期双侧鼓索神经切断或双侧唾液分泌减少后的数据无法区分。得出的结论是，双侧鼓索神经切断后出现的进食不规律是由这种部分唾液分泌减少导致的。通过对菌状乳头中的味蕾计数验证了鼓索神经切断，并对接受鼓索神经切断的大鼠的唾液腺进行了组织学检查。
