三叉神经尾侧亚核大颗粒小泡的非突触部位胞吐及膜再循环的形态观察

MORPHOLOGICAL STUDIES OF LARGE DENSE CORE VESICLE NONSYNAPTIC EXOCYTOSIS AND MEMBRANE RECYCLING IN THE TRIGEMINAL SUBNUCLEUS CAUDALIS

在切除大鼠刚髭部皮肤的刺激下,从常规醛-锇酸固定的三叉神经脊束核尾侧亚核的超薄切片中观察到:1.大颗粒小泡轴突终末非突触部位的胞吐影像;2.含致密物质的大有衣小泡,由终末质膜内陷而成,提示大颗粒小泡在终末通过有衣小泡进行膜再循环;3.大颗粒小泡也可由含致密物质的平滑内质网样的管状结构形成。本研究支持大颗粒小泡在非突触部位,通过胞吐释放递质或神经调节物的假说。

Large dense core vesicle in the trigeminal subnucleus caudalis of the rat has been observed electron microscopically.It is fixed in glutaraldehyde-osmium tetroxide following removal of the skin of the vibrissae areas.The findings of the present study are:1.Morphological evidence for exocytosis of large dense core vesicle from non-synaptic sites of the axonal terminal has been presented.2.The large coated vesicles equipped with central densities derived from the invagination of the plasma membrane.These observations suggest that membrane recycling occur at location in the terminal via these coated vesicles.3.Some large dense core vesicles may also form the tubular structures which may represent smooth endoplasmic reticulum containing dense material.This study supports the hypothesis that release of the transmitter of the great dense core vesicles occur at nonsynaptic sites by exocytosis.