Mukuno K, Witmer R
Albrecht Von Graefes Arch Klin Exp Ophthalmol. 1977 Jul 8;203(1):1-8. doi: 10.1007/BF00410042.
Contacts between melanocytes and nerve terminals in human iris stroma were investigated by means of electron microscopy. Four distinct types of nerve terminal making synaptic contacts with melanocytes can be distinguished: (1) nerve terminals containing only empty synaptic vesicles (400-800 A in diameter) and with intervening basement membrane material (separation 1000 A); (2) nerve terminals with both empty vesicles and granulated vesicles (600-1100 A in diameter) also with intervening basement membrane material (separation 750 A); (3) nerve terminals containing empty vesicles and forming close contacts with melanocytes (distance about 400 A) without interposed basement membrane material, and (4) nerve terminals containg both empty and granulated vesicles (750 A in diameter) which make closer contacts with melanocytes (distance 270 A) without interposed basement membrane material. Type (1) and type (3) nerve terminals are thought to be cholinergic; type (2) and type (4) nerve terminals appear to be adrenergic. Taking into consideration these morphologic findings and previously reported data, it seems justified to postulate the presence of trophic innervation of melanocytes in the human iris.
利用电子显微镜对人虹膜基质中黑素细胞与神经末梢之间的接触进行了研究。可区分出与黑素细胞形成突触接触的四种不同类型的神经末梢：(1) 仅含有空突触小泡（直径400 - 800埃）且其间有基底膜物质（间距1000埃）的神经末梢；(2) 既有空小泡又有颗粒小泡（直径600 - 1100埃）且其间也有基底膜物质（间距750埃）的神经末梢；(3) 含有空小泡并与黑素细胞形成紧密接触（距离约400埃）且无插入基底膜物质的神经末梢，以及(4) 含有空小泡和颗粒小泡（直径750埃）且与黑素细胞形成更紧密接触（距离270埃）且无插入基底膜物质的神经末梢。第(1)型和第(3)型神经末梢被认为是胆碱能的；第(2)型和第(4)型神经末梢似乎是肾上腺素能的。考虑到这些形态学发现和先前报道的数据，推测人虹膜中存在黑素细胞的营养性神经支配似乎是合理的。
