Sollars S I, Walker B R, Thaw A K, Hill D L
Department of Psychology, University of Nebraska Omaha, 418 Allwine Hall, Omaha, NE 68182, USA.
Neuroscience. 2006;137(4):1229-36. doi: 10.1016/j.neuroscience.2005.09.040. Epub 2005 Dec 9.
Institution of a low-NaCl diet beginning at embryonic day 3 and continued throughout pre- and postnatal development has widespread effects on the neuroanatomical organization of the first gustatory relay in the nucleus of the solitary tract. To determine when these effects are expressed postnatally, the terminal field of the chorda tympani nerve was compared between sodium-restricted and sodium-replete rats at postnatal days 15-17, postnatal days 25-27, postnatal days 35-37, and adults. Total terminal fields were significantly larger in postnatal days 35-37 and adult sodium-restricted rats compared with aged-matched controls. The group-related differences appear related more to a remodeling of the terminal field in the dorsal zone of the terminal field in controls. Specifically, the terminal field volume in the dorsal zone in controls decreased dramatically from postnatal days 25-27 to postnatal days 35-37 and then again from postnatal days 35-37 to adulthood. In contrast, the fields did not change during development in sodium-restricted rats. These findings suggest that remodeling of the chorda tympani field occurs in controls at about the developmental period of taste response maturation. The lack of remodeling in sodium-restricted rats may be explained by a corresponding lack of functional response development to sodium salts. These results also illustrate the specificity and extent of how early dietary manipulations shape the developing brainstem.
从胚胎第3天开始采用低氯化钠饮食，并在整个产前和产后发育过程中持续，这对孤束核中第一味觉中继的神经解剖组织有广泛影响。为了确定这些影响在出生后何时表现出来，在出生后第15 - 17天、出生后第25 - 27天、出生后第35 - 37天以及成年期，比较了限钠大鼠和钠充足大鼠的鼓索神经终末场。与年龄匹配的对照组相比，出生后第35 - 37天和成年限钠大鼠的总终末场明显更大。组间差异似乎更多地与对照组终末场背侧区终末场的重塑有关。具体而言，对照组背侧区的终末场体积从出生后第25 - 27天到出生后第35 - 37天急剧下降，然后从出生后第35 - 37天到成年期再次下降。相比之下，限钠大鼠的终末场在发育过程中没有变化。这些发现表明，鼓索终末场的重塑在对照组中大约在味觉反应成熟的发育时期发生。限钠大鼠缺乏重塑可能是由于对钠盐缺乏相应的功能反应发育。这些结果还说明了早期饮食操作对发育中的脑干塑造的特异性和程度。
