Schmued L C, Scallet A C, Slikker W
Division of Neurotoxicology, Food and Drug Administration, Jefferson, AR 72079-9502, USA.
Brain Res. 1995 Oct 9;695(1):64-70. doi: 10.1016/0006-8993(95)00799-v.
Domoic acid is a potent excitotoxin produced by diatoms which is subsequently passed along the marine food chain. Its chemical structure and toxicological properties are similar to kainic acid. Like kainic acid, exposure results in extensive hippocampal degeneration. The effect of domoic acid on other primate brain structures, however, is less resolved. In an attempt to clarify this issue, the present study applied a degeneration specific histochemical technique (de Olmos' cupric-silver method) to reveal degeneration within the brains of domoic acid-dosed cynomolgus monkeys. Degenerating neuronal cell bodies and terminals were found not only within the hippocampus, but also within a number of other 'limbic' structures including the entorhinal cortex, the subiculum, the piriform cortex, the lateral septum, and the dorsal lateral nucleus of the thalamus. Although the hippocampus is a component of the original limbic circuit of Papez, other components such as the mammillary bodies, the anterior nucleus of the thalamus and the cingulate cortex contained no degeneration, while a number of more recently documented efferent targets of the hippocampal formation revealed extensive degeneration. The pattern of degeneration generally correlated with those regions containing high densities of kainate receptors.
软骨藻酸是一种由硅藻产生的强效兴奋性毒素，随后会沿着海洋食物链传递。其化学结构和毒理学特性与海人酸相似。与海人酸一样，接触软骨藻酸会导致海马体广泛退化。然而，软骨藻酸对其他灵长类动物脑结构的影响尚不清楚。为了阐明这个问题，本研究应用了一种特异性的变性组织化学技术（德奥尔莫斯的铜银法）来揭示给予软骨藻酸的食蟹猴大脑中的变性情况。不仅在海马体内发现了变性的神经元细胞体和终末，还在包括内嗅皮质、下托、梨状皮质、外侧隔核和丘脑背外侧核在内的许多其他“边缘”结构中发现了变性。虽然海马体是帕佩兹原始边缘回路的一个组成部分，但其他组成部分，如乳头体、丘脑前核和扣带回皮质没有变性，而海马结构最近记录的一些传出靶点显示出广泛的变性。变性模式通常与那些含有高密度海人酸受体的区域相关。
