The involvement of voltage-operated calcium channels in somato-dendritic oxytocin release.
The involvement of voltage-operated calcium channels in somato-dendritic oxytocin release.
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DOI：
10.1371/journal.pone.0025366
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Ludwig M
中科院分区：
文献类型：
--
作者：
Tobin VA;Douglas AJ;Leng G;Ludwig M
视上核（SON）的大细胞神经元分泌催产素和加压素的轴突终末在神经垂体，但他们也释放大量的肽从他们的胞体和树突，这可以通过活动依赖性的Ca 2+内流和细胞内Ca 2+的动员调节。这种体细胞-树突状细胞释放也可以由动员细胞内Ca 2+的试剂引发，这意味着它的活性依赖性程度在生理上是不稳定的。我们研究了不同钙通道在体细胞-树突释放中的作用;阻断N型通道可减少成年和出生后第8天（PND-8）大鼠离体SONs去极化诱导的催产素释放，阻断L型仅对PND-8大鼠有效，而阻断其他类型的通道无显著影响。当催产素的释放是事先暴露于毒胡萝卜素，N-和L-型通道阻滞剂减少释放，而P/Q和R-型阻滞剂是无效的。利用共聚焦显微镜，我们发现免疫反应Cav1.2和1.3通道亚基（都形成L型通道），2.1（P/Q型），2.2（N型）和2.3（R型）的催产素和加压素神经元的胞体和树突，不同亚基的免疫荧光信号的强度不同PND-8，成年和哺乳期大鼠。使用膜片钳电生理学，N-型钙电流密度增加后毒胡萝卜素处理，但没有改变通道的电压敏感性。这些结果表明，N型钙通道的表达，位置或可用性改变时，需要高速率的体细胞-树突状肽释放。
Magnocellular neurons of the supraoptic nucleus (SON) secrete oxytocin and vasopressin from axon terminals in the neurohypophysis, but they also release large amounts of peptide from their somata and dendrites, and this can be regulated both by activity-dependent Ca2+ influx and by mobilization of intracellular Ca2+. This somato-dendritic release can also be primed by agents that mobilise intracellular Ca2+, meaning that the extent to which it is activity-dependent, is physiologically labile. We investigated the role of different Ca2+ channels in somato-dendritic release; blocking N-type channels reduced depolarisation-induced oxytocin release from SONs in vitro from adult and post-natal day 8 (PND-8) rats, blocking L-type only had effect in PND-8 rats, while blocking other channel types had no significant effect. When oxytocin release was primed by prior exposure to thapsigargin, both N- and L-type channel blockers reduced release, while P/Q and R-type blockers were ineffective. Using confocal microscopy, we found immunoreactivity for Cav1.2 and 1.3 channel subunits (which both form L-type channels), 2.1 (P/Q type), 2.2 (N-type) and 2.3 (R-type) in the somata and dendrites of both oxytocin and vasopressin neurons, and the intensity of the immunofluorescence signal for different subunits differed between PND-8, adult and lactating rats. Using patch-clamp electrophysiology, the N-type Ca2+ current density increased after thapsigargin treatment, but did not alter the voltage sensitivity of the channel. These results suggest that the expression, location or availability of N-type Ca2+ channels is altered when required for high rates of somato-dendritic peptide release.
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影响因子：
21.1
作者：
Catterall, WA;Striessnig, J;Perez-Reyes, E
通讯作者：
Perez-Reyes, E
影响因子：
16.2
作者：
KNOX, RJ;QUATTROCKI, EA;KACZMAREK, LK
通讯作者：
KACZMAREK, LK
影响因子：
2.5
作者：
DISCALAGUENOT, D;STROSSER, MT;RICHARD, P
通讯作者：
RICHARD, P
影响因子：
64.8
作者：
GUTHRIE, PB;SEGAL, M;KATER, SB
通讯作者：
KATER, SB
影响因子：
64.8
作者：
MULLER, W;CONNOR, JA
通讯作者：
CONNOR, JA