DEVELOPMENT OF TASTE RESPONSES IN RAT NUCLEUS OF SOLITARY TRACT
DEVELOPMENT OF TASTE RESPONSES IN RAT NUCLEUS OF SOLITARY TRACT
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大鼠孤束核味觉反应的发展
DOI：
10.1152/jn.1983.50.4.879
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发表时间：
1983-01-01
影响因子：
2.5
通讯作者：
MISTRETTA, CM
中科院分区：
文献类型：
--
作者：
HILL, DL;BRADLEY, RM;MISTRETTA, CM
用一氯盐、柠檬酸和盐酸、蔗糖、糖精钠和盐酸奎宁对5天大的大鼠舌头进行化学刺激，研究了孤立束核神经元的细胞外反应。在5-7日龄的大鼠中记录了多单元味觉反应，在14-20日龄、25-35日龄、50-60日龄和成年4个年龄组中记录了111个神经元的单单元味觉反应。5-7日龄大鼠NST神经元对相对高浓度（0.5 M）的NH4Cl和KCl以及柠檬酸和盐酸持续有反应。它们通常对0.5 M NaCl或0.1 M NH4Cl没有反应。14天及以上大鼠的单个NST神经元对所有0.1和0.5 M盐以及两种酸都有反应。至少75%的神经元对蔗糖和糖精钠也有反应，46%的神经元对所有这些刺激和盐酸奎宁都有反应。14天后，神经元对刺激的反应数量没有发生发育变化。在对某些化学刺激的反应程度上有实质性的发育改变。35日龄后，0.1和0.5 M NaCl、LiCl、KCl以及蔗糖和糖精钠的平均响应频率增加。NH4Cl、柠檬酸、盐酸和盐酸奎宁的反应频率在整个发育过程中没有变化。单个NST神经元对特定一氯盐反应最大的比例在发育过程中没有变化。所有年龄组的大多数单个神经元对NH4Cl、NaCl和LiCl的反应都一样好。没有NST神经元对KCl反应最大。14天及以上大鼠的反应潜伏期也没有发育差异。二级NST神经元的反应频率通常反映了在整个发育过程中来自初级传入神经——鼓室索纤维的反应变化。NST神经元盐反应频率的增加发生在发育的较晚阶段。在所有年龄段，与鼓室索神经元相比，NST对一氯盐的味觉反应包括更高的反应频率和普遍的反应特异性丧失。鼓室索和NST味觉数据的比较表明，NST神经元反应的一些发育变化仅仅反映了外周的变化，而另一些可能与NST细胞突触接触和形态特征的改变有关。
Extracellular responses from neurons in the nucleus of the solitary tract (NST) were studied in rats aged 5 days to adulthood during chemical stimulation of the tongue with monochloride salts, citric and hydrochloric acids, sucrose, sodium saccharin, and quinine hydrochloride. Multiunit taste responses were recorded in rats at 5-7 days of age and single-unit responses were recorded from 111 neurons in 4 other age groups of 14-20 days, 25-35 days, 50-60 days, and adult. NST neurons in rats aged 5-7 days consistently responded to relatively high concentrations (0.5 M) of NH4Cl and KCl and to citric and hydrochloric acid. They often did not respond to 0.5 M NaCl or to 0.1 M NH4Cl. Single NST neurons in rats aged 14 days and older characteristically responded to all 0.1 and 0.5 M salts and to both acids. At least 75% of neurons also responded to sucrose and sodium saccharin, and 46% responded to all of these stimuli and quinine hydrochloride. After 14 days, no developmental changes occurred in the number of stimuli to which neurons responded. There were substantial developmental alterations in the response magnitudes to some chemical stimuli. Average response frequencies increased after 35 days of age for 0.1 and 0.5 M NaCl, LiCl, KCl, and for sucrose and sodium saccharin. Response frequencies for NH4Cl, citric and hydrochloric acid, and quinine hydrochloride did not change throughout development. The proportion of single NST neurons that responded maximally to specific monochloride salts did not change during development. Most single neurons in all age groups responded equally well to NH4Cl, NaCl, and LiCl. No NST neuron responded maximally to KCl. There were also no developmental differences in response latencies in rats aged 14 days and older. Response frequencies of 2nd-order NST neurons generally reflect changes in responses from the primary afferent, chorda tympani fibers, throughout development. The increases in salt response frequencies from NST neurons occur comparatively later in development. At all ages, the taste responses to monochloride salts include higher response frequencies and a general loss in response specificity in NST compared to chorda tympani neurons. Comparisons of chorda tympani and NST taste data indicate that some of the developmental changes in responses of NST neurons simply reflect peripheral changes, whereas others probably relate to alterations in synaptic contacts and morphological characteristics of NST cells.