유두체 제거 후 Fundus striati의 신경종말에 관한 연구 = Study on the Synaptic Organization of Fundus Striati Following Damage to the Mammillary Bodies in Rat

다국어 초록 (Multilingual Abstract)

Morphological status of fundus striati nucleus has long been a subject of argument. It was named nucleus accumbens septi, in which instance it is a constituent of limbic system. Whereas the name 'fundus striati' means a constituent of striatal system. Authors carried the ultrastructural study on the relation between fundus striati and mammillary body which is one of the major limbic nuclei, since the ultrastructural studies of the synaptic connections of fundus striati as a striatal chracteristics, with cerebral cortex, CM-PF nuclei of thalamus, globus pallidus, substantia nigra, etc., are proved recently. The left mammillary bodies of rats were electrically coagulated on the stereotaxic apparatus. Following the time course of 2 hrs, 2 days, 1 week and 2 weeks, the rats were perfused with 1% glutaraldehyde-1% paraformaldehyde solution (phosphate buffer, pH 7.2∼7.4) under nembutal anesthesia. The brains were carefully inspected. Tissue punchings from ipsilateral fundus striati were fixed overnight in the same fixative and later fixed again 8in 2% osmic acid solution.
Ultrathin sections stained with uranyl acetate-lead citrate sequence were observed with JEOL 100 CX electron microscope. It was proved that the mammillary body of rat send axons to the fundus striati. Degenerated terminal boutons of mammillo-striatal neurons exhibit the asymmetric axo-spinous synapses. A few degenerated boutons synapsed directly with dendrite, but they were interpreted as retracted axo-spinous synapses. There were two kinds of degeneration, i.e., lucent degeneration and dark degeneration.
Lucent type shows the depletion and/or dissolution of synaptic vesicles, and at least some of lucently degenerated terminals were expected to restore their synaptic vesicles or to be recovered. Darkly degenerating terminals were interpreted as an irreversible type of degeneration. Some times there found the dark cells. But it is not clear, if the dark cells represent the projecting cells from fundus striati to mammillary body or artefacts occurred during fixation procedures. Summarizing the above results, the fundus striati is the bridge nucleus that interrelate the motivation of limbic system with the control of striatal system.