Fountain S B, Hennes S K, Teyler T J
Department of Neurobiology, Northeastern Ohio Universities College of Medicine, Rootstown 44272.
Fundam Appl Toxicol. 1988 Aug;11(2):221-8. doi: 10.1016/0272-0590(88)90146-7.
Aspartame (APM) is a low-calorie sweetener recently approved and released for widespread use in the United States. However, concerns still exist that APM consumption may be responsible for adverse neurological and psychological effects in some people. In addition, recent reports indicate that APM exposure may alter regional brain neurotransmitter levels. The present study assessed the effects of APM and its amino acid moieties on rat hippocampal slice excitability and plasticity. Specifically, tests of excitatory systems, inhibitory systems, and synaptic plasticity (induction of long-term potentiation--LTP) were administered postexposure. Exposures of 0.01, 0.1, 1, and 10 mM APM potentiated the response of hippocampal CA1 pyramidal cells, but had no apparent effect on local inhibitory systems. APM exposure did not block the establishment of LTP at any dose despite the potentiation of pyramidal cell response observed postexposure. In addition, 0.1 mM phenylalanine (PHE) produced a greater increase in excitability than that produced by an equivalent dose of APM, 0.1 mM aspartic acid (ASP) and 0.1 mM phenylalanine methyl ester (PM) produced effects comparable to those produced a smaller, but reliable, change in hippocampal CA1 excitability relative to baseline. Like APM, none of the amino acids produced detectable changes in inhibitory systems or neuronal plasticity.
阿斯巴甜（APM）是一种低热量甜味剂，最近在美国被批准并广泛使用。然而，仍有人担心食用APM可能会对某些人的神经和心理产生不良影响。此外，最近的报告表明，接触APM可能会改变大脑区域的神经递质水平。本研究评估了APM及其氨基酸部分对大鼠海马切片兴奋性和可塑性的影响。具体而言，在接触后对兴奋性系统、抑制性系统和突触可塑性（长期增强——LTP的诱导）进行了测试。0.01、0.1、1和10 mM的APM暴露增强了海马CA1锥体细胞的反应，但对局部抑制系统没有明显影响。尽管在接触后观察到锥体细胞反应增强，但APM暴露在任何剂量下都没有阻断LTP的建立。此外，0.1 mM苯丙氨酸（PHE）比同等剂量的APM产生了更大的兴奋性增加，0.1 mM天冬氨酸（ASP）和0.1 mM苯丙氨酸甲酯（PM）产生的效果与较小但可靠的海马CA1兴奋性相对于基线的变化相当。与APM一样，这些氨基酸都没有在抑制系统或神经元可塑性方面产生可检测到的变化。
