Papka R, Peretz B, Tudor J, Becker J
J Neurobiol. 1981 Sep;12(5):455-68. doi: 10.1002/neu.480120505.
Neurons of Aplysia californica are naturally pigmented and the pigment accumulates with age. In the present study the pigment was examined in the same neuron from Aplysia of three postmetamorphic ages: young, sexually mature, and old. The large central neuron, R2, was examined by light and electron microscopy to determine if the pigment possessed properties similar to lipofuscin pigment seen in aging mammalian neurons. We used the same microscopic techniques that demonstrate the presence of lipofuscin in mammalian neurons. Light microscopic studies demonstrated a regional correlation between autofluorescence, staining with Sudan Black, and the naturally occurring pigment in old R2s. Electron microscopic studies revealed the presence of large vacuolated and lamellated membrane-bound bodies in the peripheral cytoplasm of old R2s, similar to those found in mammalian neurons. The bodies were located in the same region in which autofluorescence and Sudan Black staining were observed. Although the naturally occurring pigment accumulates with age, it acquires characteristics of lipofuscin pigment in the neurons of older sexually mature animals. The presence of these pigment characteristics can be used as an index of aging in Aplysia neurons as they are in mammalian neurons.
加州海兔的神经元天然带有色素，且色素会随着年龄增长而积累。在本研究中，对来自三个变态后年龄阶段（幼体、性成熟体和老年体）的加州海兔同一神经元中的色素进行了检测。通过光学显微镜和电子显微镜对大型中央神经元R2进行检测，以确定该色素是否具有与衰老哺乳动物神经元中所见脂褐素相似的特性。我们采用了与证明哺乳动物神经元中存在脂褐素相同的显微技术。光学显微镜研究表明，老年R2神经元中的自发荧光、苏丹黑染色与天然存在的色素之间存在区域相关性。电子显微镜研究显示，老年R2神经元的外周细胞质中存在大型空泡化和层状膜结合体，类似于在哺乳动物神经元中发现的那些。这些物体位于观察到自发荧光和苏丹黑染色的同一区域。尽管天然存在的色素会随着年龄增长而积累，但在年龄较大的性成熟动物的神经元中，它获得了脂褐素的特征。这些色素特征的存在可作为海兔神经元衰老的指标，就如同它们在哺乳动物神经元中一样。
