发信人: adamant (笨猫杀手), 信区: Biology
标 题: Re: membrane potential
发信站: The unknown SPACE (Tue May 23 12:35:58 2000), 转信

【 在 penh (怕怕~与bbs共存亡) 的大作中提到: 】
: 常在文献上看到membrane potential = 200 mV, blah...
: 这个电压夸的距离就是膜的厚度吗?

200 mv ? is it possible ?
Normally, rest membrane potential of neurons is about minus 50 to 80 mv,
as the outside membrane be the reference potential. For some astrocytes,
the value is about minus 20 to 30 mv. I can not recall the value for muscle
cells, but it is also minus.
You are right that you can assume the potential is distributed on the
membrane(double layer). Because compared with the resistance and capacitance
of the membrane, intra- and extracellular contributions can both be ignored.
Some voltage-gated ion channel can sensor the local voltage change
intracellularly, such as nicotine receptor(segment4 is the sensor).
For the distribution and transferation of the voltage on soma, dentrites,
and axons, it is more complicated, but you can find the reference.


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※ 修改:．adamant 于 May 23 12:45:53 修改本文．[FROM: 136.165.1.37]
※ 来源:．The unknown SPACE bbs.mit.edu．[FROM: 136.165.1.37]