Kachi T, Banerji T K, Quay W B
J Auton Nerv Syst. 1980 Oct;2(3):241-58. doi: 10.1016/0165-1838(80)90014-4.
This work describes a special ultrastructural feature, the invagination complex (IC), involving the plasma membrane of nerve endings on adrenomedullary adrenaline cells. Quantitative characteristics of the IC and their changes were studied in 122 male albino (Holtzman strain) rats in 3 surgical groups: normal (non-operated, NO) sham-operated (SO) and pinealectomized (PX), all maintained in a standardized daily photoperiod (light : dark 12 : 12 h). Animals were decapitated 14 days postsurgery and at 8 specific times during the light : dark cycle. Left adrenal glands were removed, dn strain) rats in 3 surgical groups: normal (non-operated, NO) sham-operated (SO) and pinealectomized (PX), all maintained in a standardized daily photoperiod (light : dark 12 : 12 h). Animals were decapitated 14 days postsurgery and at 8 specific times during the light : dark cycle. Left adrenal glands were removed, dn strain) rats in 3 surgical groups: normal (non-operated, NO) sham-operated (SO) and pinealectomized (PX), all maintained in a standardized daily photoperiod (light : dark 12 : 12 h). Animals were decapitated 14 days postsurgery and at 8 specific times during the light : dark cycle. Left adrenal glands were removed, dissected and prepared for electron microscopy. In section profiles the diameter of each IC was usually 0.12-0.40 micrometers, and the depth 0.2-1.0 micrometers. They were frequently seen to be located near the synaptic complex (or the active zone). Coated pits, about 50 nm wide and 60 nm deep, often opened near the bottom of the invaginations of the IC. In NO animals, relative number and depth of the ICs showed daily rhythmic changes with minimal values about 1 h after onset and maximal (acrophase) values 3--5 h later (P less than 0.02 to less than 0.005, depending on index or measure). These changes occurred 3--5 h earlier, but less apparently, in SO animals, and appeared to be more greatly modified and dampened in PX animals. Two-way analysis of variance (ANOVA) and t-tests applied to 11 kinds of indices derived from counts and measurements of the ICs, support the differences between surgical groups, at least in many instances (P less than 0.05 to less than 0.001). It is concluded that the IC is a characteristic and dynamic feature of the nerve terminals and that it may possibly have a role in such phenomena as recycling of synaptic vesicles or related membrane constituents. It is also concluded that significant time-of-day and neuroendocrine effects are demonstrable in these structures, and that the time-of-day effects shown in these chronic studies have importance in the design of acute experiments designed to further test the functional relations and importance of ICs.
本研究描述了一种特殊的超微结构特征——内陷复合体（IC），它涉及肾上腺髓质肾上腺素细胞上神经末梢的质膜。在3个手术组的122只雄性白化（霍尔兹曼品系）大鼠中研究了IC的定量特征及其变化：正常组（未手术，NO）、假手术组（SO）和松果体切除组（PX），所有大鼠均维持在标准化的每日光照周期（光照：黑暗12:12小时）。术后14天以及在光照：黑暗周期的8个特定时间将动物断头。摘除左肾上腺，解剖并制备用于电子显微镜检查。在切片轮廓中，每个IC的直径通常为0.12 - 0.40微米，深度为0.2 - 1.0微米。它们经常位于突触复合体（或活性区）附近。宽约50纳米、深约60纳米的有被小窝常常在IC内陷底部附近开口。在正常组动物中，IC的相对数量和深度呈现每日节律性变化，起始后约1小时达到最小值，3 - 5小时后达到最大值（高峰期）（P小于0.02至小于0.005，取决于指标或测量方法）。在假手术组动物中，这些变化提前3 - 5小时出现，但不太明显，而在松果体切除组动物中，变化似乎受到更大的改变和抑制。对从IC计数和测量得出的11种指标进行的双向方差分析（ANOVA）和t检验支持了手术组之间的差异，至少在许多情况下是这样（P小于0.05至小于0.001）。得出的结论是，IC是神经末梢的一个特征性和动态特征，它可能在诸如突触小泡或相关膜成分的循环利用等现象中发挥作用。还得出结论，在这些结构中可以证明明显的每日时间和神经内分泌效应，并且这些慢性研究中显示的每日时间效应在设计用于进一步测试IC功能关系和重要性的急性实验中具有重要意义。
