著者
Yutaka MITSUHASHI Koji HAYASAKI Taichiro KAWAKAMI Takashi NAGATA Yuta KANESHIRO Ryoko UMABA Kenji OHATA
出版者
The Japan Neurosurgical Society
雑誌
Neurologia medico-chirurgica (ISSN:04708105)
巻号頁・発行日
vol.56, no.6, pp.326-339, 2016 (Released:2016-06-15)
参考文献数
75
被引用文献数
13 27

The cavernous sinus (CS) is one of the cranial dural venous sinuses. It differs from other dural sinuses due to its many afferent and efferent venous connections with adjacent structures. It is important to know well about its complex venous anatomy to conduct safe and effective endovascular interventions for the CS. Thus, we reviewed previous literatures concerning the morphological and functional venous anatomy and the embryology of the CS. The CS is a complex of venous channels from embryologically different origins. These venous channels have more or less retained their distinct original roles of venous drainage, even after alterations through the embryological developmental process, and can be categorized into three longitudinal venous axes based on their topological and functional features. Venous channels medial to the internal carotid artery “medial venous axis” carry venous drainage from the skull base, chondrocranium and the hypophysis, with no direct participation in cerebral drainage. Venous channels lateral to the cranial nerves “lateral venous axis” are exclusively for cerebral venous drainage. Venous channels between the internal carotid artery and cranial nerves “intermediate venous axis” contribute to all the venous drainage from adjacent structures, directly from the orbit and membranous skull, indirectly through medial and lateral venous axes from the chondrocranium, the hypophysis, and the brain. This concept of longitudinal venous axes in the CS may be useful during endovascular interventions for the CS considering our better understandings of its functions in venous drainage.
著者
Yujiro Nagasaka Shoko Hososhima Naoko Kubo Takashi Nagata Hideki Kandori Keiichi Inoue Hiromu Yawo
出版者
The Biophysical Society of Japan
雑誌
Biophysics and Physicobiology (ISSN:21894779)
巻号頁・発行日
vol.17, pp.59-70, 2020 (Released:2020-07-22)
参考文献数
51
被引用文献数
5

Microbial rhodopsin is a large family of membrane proteins having seven transmembrane helices (TM1-7) with an all-trans retinal (ATR) chromophore that is covalently bound to Lys in the TM7. The Trp residue in the middle of TM3, which is homologous to W86 of bacteriorhodopsin (BR), is highly conserved among microbial rhodopsins with various light-driven functions. However, the significance of this Trp for the ion transport function of microbial rhodopsins has long remained unknown. Here, we replaced the W163 (BR W86 counterpart) of a channelrhodopsin (ChR), C1C2/ChRWR, which is a chimera between ChR1 and 2, with a smaller aromatic residue, Phe to verify its role in the ion transport. Under whole-cell patch clamp recordings from the ND7/23 cells that were transfected with the DNA plasmid coding human codon optimized C1C2/ChRWR (hWR) or its W163F mutant (hWR-W163F), the photocurrents were evoked by a pulsatile light at 475 nm. The ion-transporting activity of hWR was strongly altered by the W163F mutation in 3 points: (1) the H+ leak at positive membrane potential (Vm) and its light-adaptation, (2) the attenuation of cation channel activity and (3) the manifestation of outward H+ pump activity. All of these results strongly suggest that W163 has a role in stabilizing the structure involved in the gating-on and -off of the cation channel, the role of “gate keeper”. We can attribute the attenuation of cation channel activity to the incomplete gating-on and the H+ leak to the incomplete gating-off.