Haldar C, Guchhait P
Pineal Research Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India.
J Exp Zool. 2000 Jul 1;287(2):145-50. doi: 10.1002/1097-010x(20000701)287:2<145::aid-jez4>3.0.co;2-k.
It has been reported that owls (Strigiformes) do not have a pineal gland. However, our light microscopy study revealed an intermediate form of tubulofollicular and solid-type large pineal gland in a tropical owlet, Athene brama. The epithelial cells forming follicles (6-8) in the distal region and the solid cluster of parenchymal cells of different diameters in the proximal region anteriorly tapered with a long cylindrical stalk and continued into commissural organs and choroid plexus. The intrapineal localization of perivascular nerve fibers and blood vessels clearly explained the sympathetic innervation as well as vascularization of this neuroendocrine gland. Further, electron microscopy revealed a developed intracellular structure of the pinealocytes with a large number of mitochondria, Golgi bodies, and granular as well as clear vesicles in the process terminals. The evidence of intrapinealocyte lipid droplets and dense bodies and a moderate amount of melatonin in plasma (ranging from 100-365 pg/mL) during different reproductive phases finally proved a defined secretory activity of the gland in this tropical, nocturnal bird.
据报道，猫头鹰（鸮形目）没有松果体。然而，我们的光学显微镜研究发现，在热带小猫头鹰（纹鸮）中存在一种管状滤泡型和实体型大型松果体的中间形式。在远端区域形成滤泡（6 - 8个）的上皮细胞以及近端区域不同直径实质细胞的实体簇向前逐渐变细，形成一个长圆柱形的柄，并延续到连合器官和脉络丛。松果体内血管周围神经纤维和血管的定位清楚地解释了这个神经内分泌腺的交感神经支配以及血管形成。此外，电子显微镜显示松果体细胞具有发达的细胞内结构，在突起末端有大量线粒体、高尔基体以及颗粒状和清亮小泡。松果体细胞内脂滴和致密体的证据以及在不同繁殖阶段血浆中适量的褪黑素（范围为100 - 365 pg/mL）最终证明了这种热带夜行性鸟类的松果体具有明确的分泌活性。
