Margotta Vito, Caronti Brunella, Colombari Paolo Tito, Castiglia Riccardo
Dipartimento di Biologia animale e dell'Uomo (Sede di Anatomia comparata), Università di Roma "La Sapienza", Italy.
Ital J Anat Embryol. 2007 Jan-Mar;112(1):45-58.
It is now well known that the Teleosts among Osteichthyes, Urodele and Anuran Amphibians, Lacertilian Reptiles possess encephalic natural proliferative activities even into adulthood, as demonstrated by a great number of researches performed both under normal and various experimental conditions. Few years ago we have undertaken in adult heterothermic vertebrates a reappraisal on spontaneous cerebral proliferative events involving some organisms (Podarcis sicula, Triturus carnifex, Rana esculenta, Carassius carassius) representative of these vertebrates and belonging to the same or phylogenetically similar species used by previous researchers in studies having the same object. In our investigations, these performances were revealed by a proliferative immunocytochemical marker, the Proliferating Cell Nuclear Antigen (PCNA). At this point of our study in the scenario emerging from findings a missing piece is represented by Petromyzontidae. To fill up this gap in the present investigation, using our usual test, we have paid attention to adult specimens of Lampetra planeri. The obtained immunostaining panorama has revealed the presence of a considerable number of spontaneous proliferative activities. These events might differ in quantity, in various encephalic districts. PCNA-labelled cells appeared scattered in the cranial portion of olfactory bulbs, while the PCNA expression has been observed steadily localized with a distinctly continous distribution in cells interposed among the ependymal epithelium which lines the cavities of the proximal portion of the olfactory region and of the cerebral ventricles. DNA synthesis activity has been also found in cells scattered in the telencephalic, diencephalic, mesencephalic and medulla oblongata periventricular grey. This immunoreactivity was not revealable in the cerebellum. Our findings are discussed in the light of bibliographic news.
现在众所周知，硬骨鱼纲中的硬骨鱼、有尾目和无尾目两栖动物、蜥蜴目爬行动物即使到成年也具有脑内自然增殖活动，大量在正常和各种实验条件下进行的研究都证明了这一点。几年前，我们对成年变温脊椎动物中涉及一些代表这些脊椎动物的生物体（意大利壁蜥、意大利真螈、食用蛙、鲫鱼）的自发性脑增殖事件进行了重新评估，这些生物体与先前研究人员在具有相同目标的研究中使用的属于相同或系统发育相似的物种。在我们的研究中，这些表现通过增殖免疫细胞化学标记物增殖细胞核抗原（PCNA）得以揭示。在我们研究的这个阶段，从研究结果中出现的情况来看，七鳃鳗科是缺失的一环。为了填补本研究中的这一空白，我们使用常规测试，关注了溪七鳃鳗的成年标本。所获得的免疫染色全景显示存在大量自发性增殖活动。这些事件在数量上可能因不同的脑区而异。PCNA标记的细胞散在于嗅球的颅部，而PCNA表达在位于嗅区近端部分和脑室腔衬里的室管膜上皮之间的细胞中呈明显连续分布且稳定定位。在端脑、间脑、中脑和延髓室周灰质中散在的细胞中也发现了DNA合成活性。在小脑中未发现这种免疫反应性。我们根据文献报道对研究结果进行了讨论。
