Morphological and functional changes of taste buds on the soft palate during development.

对大鼠软腭和舌生后发育过程中味蕾的定量观察表明，出生时软腭上有200个味蕾，与3周龄时一样多，但有50个味蕾存在味孔。而新生大鼠舌前部菌状乳头内味蕾数不足100个，未观察到味孔，生后4周内味蕾数逐渐增多，最多达200个。在大鼠和仓鼠的GSP的电生理记录表明，味觉刺激与甜物质的软腭产生强大的反应的GSP神经。大鼠GSP不仅对糖，而且对各种氨基酸产生了强烈的反应。在大鼠鼓索中，L-氨基酸比D-形式更有刺激性，而GSP对D-氨基酸的反应比对映体更好。此外，在仓鼠的GSP和/或CT神经的双边横切导致在一个显着减少的条件性味觉厌恶蔗糖。切片效果的顺序为GSP + CT > GSP（）SY ≥。（）CT > sham。由于软腭上分布着数量众多的味蕾，且对含有多种氨基酸的甜味物质有较强的反应性，因此软腭的味觉功能在出生后发育早期对乳汁的摄取起着重要的作用。

Quantitative examination of taste buds on the soft palate and the tongue in the rat during the postnatal development revealed that there exist 200 taste buds on the soft palate at birth as many as in 3-week-old although taste pore were observed in 50 taste buds. On the contrary, less than 100 taste buds, without observation of taste pore, existed in fungiform papillae on the anterior tongue in new born rats, and the number of taste buds postnatally increased during 4 weeks, reached to the maximum of 200. Electrophysiological recordings from the GSP in the rat and hamster showed that taste stimulation with sweet substances on the sofr palate produces robust responses on the GSP nerve. The rat GSP produced robust responses not only to sugars but also to various amino acids. In the rat chorda tympani, L-amino acids are more stimulatory than the D-forms, while the GSP responds better to Damino acids compared to the enantiomers. Also, bilateral transection of the GSP and/or CT nerves in the hamster resulted in a significant reduction of the conditioned taste aversion for sucrose. The order of the sectioning effects was GSP + CT > GSP (〕SY.gtoreq.〔) CT > sham. Considering numeral taste buds distributed on the soft palate, and the strong responsiveness for sweet substances including many amino acids, gustatory function of the soft palate should play an important role on the ingestion of milk during early development in postnatal stage.