McNeill M E, Whitehead D S
J Neural Transm. 1979;45(2):149-64. doi: 10.1007/BF01250090.
Pinealocyte ultrastructure has been studied in four sterile, four pregnant and three fertile but non-pregnant females, and also in three reproductively active male pigmented Duncan Hartley guinea pigs. Synaptic ribbons are dense, rod-like structures with a linear arrangement of clear vesicles periodically spaced on both sides of the rodlet. Although these structures were observed in the pinealocytes of all of the animals studied, they were scarce and difficult to locate in tissue from the fertile, non-pregnant females and from the reproductively active males. They were numerous in the pineal glands of the pregnant and sterile females. Typically they lie perpendicular to the cell membrane of the pinealocyte polar process and in close proximity to a polar process of a neighboring cell. The increased incidence of synaptic ribbons in pinealocytes which appear to be in a heightened state of activity strongly suggests a function for this structure. Synaptic ribbons are also present in sensory systems such as rods and cones of the retina, hair cells of the organ of Corti and hair cells of the vestibular apparatus. This fact, plus the photoreceptor function of pinealocytes in lower vertebrates, lends credence to the possibility that this structure may serve a sensory or receptor function in the guinea pig gland.
在4只不育、4只怀孕以及3只可育但未怀孕的雌性豚鼠，以及3只生殖活跃的雄性有色邓肯·哈特利豚鼠中研究了松果体细胞的超微结构。突触带是致密的杆状结构，在小杆两侧有呈线性排列且周期性间隔的清亮小泡。尽管在所研究的所有动物的松果体细胞中都观察到了这些结构，但在可育未怀孕雌性动物和生殖活跃雄性动物的组织中，它们稀少且难以定位。它们在怀孕和不育雌性动物的松果体中数量众多。通常，它们垂直于松果体细胞极性突起的细胞膜，并紧邻相邻细胞的一个极性突起。在似乎处于活动增强状态的松果体细胞中，突触带的发生率增加，这有力地表明了该结构具有某种功能。突触带也存在于感觉系统中，如视网膜的视杆和视锥细胞、柯蒂氏器的毛细胞以及前庭器官的毛细胞。这一事实，加上低等脊椎动物松果体细胞的光感受器功能，使得这种结构可能在豚鼠松果体中发挥感觉或感受器功能这一可能性更具可信度。
