Povlishock J T, Kriebel R M, Seibel H R
Am J Anat. 1975 Aug;143(4):465-84. doi: 10.1002/aja.1001430405.
The pineal gland of the 13-lined ground squirrel (Citellus tridecemlineatus) has been examined at the light and electron microscopic level. This gland is composed of low-density parenchymal cells interspersed among which are occasional glial, vascular and neural elements. Punctuating the glandular parenchymal mass are prominent perivascular and intercellular spaces. The parenchymal cells possess numerous mitochondria and less prominent profiles of rough and smooth-surfaced endoplasmic reticulum. Golgi apparatus, microtubules and lipid droplets of varying size and electron density constitute regular cytoplasmic features, with dense-core vesicles being present occasionally. The parenchymal cells have numberous processes. One among these in each cell extends for several micra to terminate in a bulbous expansion containing both clear and dense-core vesicles and occasional electron-dense inclusions. These bulbous terminals are found within the perivascular and intercellular spaces where they course in close proximity to both other parenchymal elements and axon terminals. Glial cells and their processes invest the pineal periphery and incompletely separate the parenchymal cells.
对十三条纹地松鼠（Citellus tridecemlineatus）的松果体进行了光镜和电镜水平的检查。该腺体由低密度实质细胞组成，其间散布着偶尔出现的神经胶质、血管和神经成分。突出的血管周围间隙和细胞间隙穿插于腺实质团块中。实质细胞拥有大量线粒体，粗糙型和光滑型内质网轮廓不那么突出。高尔基体、微管以及大小和电子密度各异的脂滴构成了规则的细胞质特征，偶尔还存在致密核心小泡。实质细胞有许多突起。每个细胞中的一个突起延伸数微米，终止于一个球状膨大，其中含有清亮和致密核心小泡以及偶尔的电子致密内含物。这些球状终末见于血管周围间隙和细胞间隙内，在那里它们与其他实质成分和轴突终末紧邻。神经胶质细胞及其突起围绕松果体周边，并未完全分隔实质细胞。
