[Neuroscience] Re: Equation that explains the behaviour of a
circuit in voltage clamp
(by connelly.bill from gmail.com)
Sat Apr 4 20:40:50 EST 2009
>and the dV on the membrane is Vp*Rm/(Rs+Rm). We often assume that
> dV=Vp but this is valid only if Rs is negligibly small compared to
Wait, is that dV, or is that just the steady state value of Vm, i.e.
Rs and Rm are acting as a voltage divider.
Assuming a neglible Rs,
Maybe, to include Rs, it should be
Where Vs is the voltage over Rs, which is Itot*Vs
On Apr 5, 1:30 pm, "Bill.Connelly" <connelly.b... from gmail.com> wrote:
> On Apr 5, 10:51 am, r norman <r_s_nor... from comcast.net> wrote:
> > On Sat, 4 Apr 2009 14:57:34 -0700 (PDT), "Bill.Connelly"
> > Whether or not there is Rs, the membrane current is still Im = V/Rm +
> > C dV/dt where V is the true transmembrane voltage, not a measured
> > voltage contaminated by the I * Rs term.
> Ohhhhh... okay then.... So
> Im = Vm/Rm + C dVm/dt
> And Vm... well
> No, that still isn't right, because Vm tends absolutely towards Vcmd.
> Somehow I need to take into account Im*Rs
> I'm sorry I'm being stupid here. I'm trying to grasp what you're
> saying, I'm just not very good at the math and the physics.
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