Please send replys to Mark. Thanks. Ron
---------- Forwarded message ----------
Date: Fri, 17 May 96 08:44 EDT
From: Mark Casteel <MAC13 at PSUVM.PSU.EDU>
To: tips at fre.fsu.umd.edu
Subject: neuronal threshold
A quick question for those of you with expertise in neuropsychology. When I
was an undergrad (and grad student as well), I was taught that the threshold
for an action potential was close to -55 mv. This value also seems to be
backed up by the classic Scientific American article by Stevens (1976).
Although I realize there are no absolutes, I've been teaching my students to
use the value of -55mv as an approximate threshold value.
Interestingly, I've just switched to the Weiten text, and in one of his figures
the threshold value is shown as -40mV. I also had a student that had two
neurophysiology courses that stated she was taught the threshold was closer
to -40 than -55. I'd just like to be cleared up on this issue. Is there a
relatively well-accepted threshold value, and if so, what is it? TIA.
Mark Casteel
Penn State York
MAC13 at PSUVM.PSU.EDU
